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Thin Film Deposition - Science topic

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I want to calculate the thickness of a thin film deposited on glass with the transmittance using the Swanpoel method:
I use the transmittance spectrum of the sample (film + glass) or the T/T0 ratio ( T is the transmittance of (film+ glass) and T0 is the transmittance of the glass).
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To calculate the thickness of a thin film using the Swanepoel method, follow these steps:
  1. Obtain Transmittance Spectra: Measure the transmittance spectrum of the film on glass (T) and the transmittance spectrum of the bare glass (T₀).
  2. Calculate T/T₀ Ratio: Compute the ratio of the transmittance of the film on glass to the transmittance of the bare glass for each wavelength.
  3. Identify Interference Maxima: Identify the wavelengths where the transmittance shows interference maxima (peaks).
  4. Determine Optical Path Difference (OPD): Calculate the optical path difference (OPD) for each interference maximum using the formula:
OPD=2ndcos⁡(θ)
where n is the refractive index of the film, d is the film thickness, and θ is the angle of incidence
5. Calculate Thickness: Use the OPD and the corresponding wavelength to calculate the film thickness dd using the formula:
d=OPD/2n
You can find the thin film thickness from cross-sectional FE-SEM imaging.
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We are attempting to measure the ISHE signal using a Ta layer (sputter-deposited, 5-10 nm) on top of YIG thin films (deposited via PLD).
While we obtain good FMR spectra with damping in the 10^{-3} to 10^{-4} range, we are not successful in detecting the ISHE signal.
Could someone please explain what factors need to be considered for these oxides to observe the ISHE signal successfully?
Note: we have tungutan (W) and Tantalum (Ta) sputtering targets not Platinum
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The ISHE signal is dependent on the type of interface you have and is caracterized by the geff factor which is the spin mixing conductance. Thus you want a surface with little defects as possible.
For rough surfaces you also have the two magnon scattering process which increases the linewidth (dH) making the ISHE voltage/current to be small as it is proporcional to (1/dH)^2. Note that when caracterizing YIG one looks to the Landau alfa parameter but when talking about ISHE one should looks at the linewidht itself.
In your case it seens too me you just have a large dH and are not using enough rf power to see the signal.
PS: W and Ta have negative Hall angle, thus for your referance frame the ISHE voltage of those materials should be opposite to Pt,Pd or Au.
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Despite significant advancements in thin film deposition techniques, the precise role and control of atomic-scale defects in determining the properties of emerging semiconductor materials remain underexplored. Understanding these mechanisms could pave the way for the development of more efficient and reliable electronic and optoelectronic devices. What experimental and theoretical approaches could be employed to investigate this area further, and what might be the potential challenges and implications of these defects in practical applications?
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Atomic-scale defects can significantly influence the electronic and optical properties of thin films in emerging semiconductor materials. The potential effects include:
1. Altered Electronic Properties: Defects such as vacancies, interstitials, and antisite defects can modify the electronic band structure, potentially creating new energy levels within the bandgap. This can affect the material's conductivity and carrier mobility.
2. Impact on Optical Properties: Defects can lead to changes in absorption, reflection, and transmission spectra. For example, they can introduce localized states that absorb specific wavelengths, thus altering the material's optical response.
3. Influence on Photoluminescence: The presence of defects can quench or enhance photoluminescence, depending on their nature and density. This effect is crucial for optoelectronic applications such as light-emitting diodes and lasers.
4. Modulation of Charge Transport: Defects can act as traps for charge carriers, thereby reducing carrier lifetime and mobility. This can significantly impact the efficiency of devices like solar cells and transistors.
5. Changes in Refractive Index: Atomic-scale defects can alter the refractive index of thin films, affecting their use in applications requiring precise optical properties, such as in waveguides and photonic devices.
Overall, managing defects is crucial for optimizing the performance of semiconductor thin films in various electronic and optoelectronic applications.
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How to do characterization (FT-IR, XRD) of polymer and MOF films electro-deposited on GCE. Because if I separate it from the electrode, it may damage the material. right. The problem is that most techniques require sample preparation. Any possible solution. researchers
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Hello friend
I do not know the process.
But I may suggest a process that may or may not be possible. (Some experts may correct my suggestions)
I am answering as if I am experimenting.
I will try to take two XRD. One for material with the electrode and the other for the electrode material only.
I will compare the two XRD and I will report the XRD and will mention these peaks are due to the material and those peaks are due to the electrode.
Thank you. And wait for a possible solution.
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I'm currently engaged in research focused on the expansion of transition metal oxide thin films. Our approach involves depositing transition metal films on two distinct substrates using either electron beam or thermal evaporation techniques. Following deposition, we subject these films to thermal oxidation under identical conditions. This process leads to alterations in the morphology of the resulting metal oxide films. I'm curious about the reasons behind these morphological changes observed in both instances. Could you recommend a comprehensive paper or book that delves into this phenomenon?
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Thank You Fitsum Addis Hailu for you response. You are right but I want to know more the connection between nucleation growth and substrate which modify the grown surface morphology of metal oxide.
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It is okay that more mass loading may increase resistance and therefore capacitance will be less. However, what should happen ideally when we increase mass loading?
If I use very less mass loading, will it give better results?
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every time i calcualte the specific capacitence it comes less than 50. dicharge time also comes in 5 to 15 seconds? what is possible reason for this. I am using glassy carobn electrode with 0.07cm2 area?it is the imapct of low mass loading? kindly guide?hihgly appreciated. i am using sp-300 biologic potentiostae and techiques for the GCD is gpcl2?
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We are trying to sputter a metallic target. We can clearly see the plasma however after depositing for more than 30 minutes there is no deposition on the substrate. What can be the reason for this? need expert advice.
Thanks!
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I think that the gas pressure is a critical factor. Increasing the gas pressure will raise the collision frequency and the sputtering rate, but it will reduce the average mean free path of the sputtered atoms to reach the substrate and will also reduce the adhesion.
So, it is better to control the gas pressure in low range to have better adhesion and allow a longer mean free path of the sputtered atoms reaching the substrate.
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I want to characterize the residual stress in copper thin film deposited on fused silica. Kindly let me know how to do that.
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For this, please refer to the preprint article link http://dx.doi.org/10.13140/RG.2.2.23849.40808, titled “Determining and quantifying chemically produced stresses in (atoms of) electronic and crystalline materials”
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While Al2O3 has 3 gm/cc and Tin oxide has 7 gm/cc measured on as low as 8nm films on same substrate, so how a rarer material can provide seeding to a denser material? As it seems that in rarer (atomic density of SnO2 is ~1.57 times to Al2O3) material, atoms are far away and would hamper growth of denser material. Both films are amorphous and it seems that 8nm can grow dense so interface should also be better in denser thin film.
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Using ALD-Al2O3 as a seeding layer for tin oxide deposition by thermal Atomic Layer Deposition (ALD) on a substrate involves a nuanced understanding of material properties and interface dynamics.
While it may seem counterintuitive that a rarer material like ALD-Al2O3 can effectively seed the deposition of a denser material like tin oxide, the process is more complex than just atomic density.
The key lies in the surface energy and reactivity of the ALD-Al2O3 layer. Despite its lower atomic density compared to tin oxide, ALD-Al2O3 can provide a favorable surface for nucleation and initial growth of tin oxide due to its high surface energy and reactivity.
Additionally, the atomic arrangement and bonding configuration on the surface of ALD-Al2O3 can facilitate the nucleation and growth of tin oxide atoms in a controlled manner, leading to a well-defined interface between the two materials.
While the atomic density difference between the two materials may initially raise concerns about the effectiveness of ALD-Al2O3 as a seeding layer, the overall surface properties and reactivity play a more significant role in determining the success of the deposition process.
In conclusion, the use of ALD-Al2O3 as a seeding layer for tin oxide deposition is a sophisticated engineering strategy that leverages surface energy, reactivity, and bonding configurations to achieve controlled growth and interface quality, despite the atomic density differences between the two materials.
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Hello everyone,
Can you recommend a publication or a book that does EIS AND Mott Schottky analysis in the combined use of polymers and metal oxides?
I need books, publications, or any other sources that provide guidance on EIS and Mott Scotty analysis of thin films deposited on polymers with metal oxides at a certain potential. Any examples needed to help comment... Thanks
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I need detailed interpretations and information rather than the magazine. To interpret your own results
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PLD thin film deposition technique is used to deposits the layers of ceramic oxides by the laser ablation process. There is some use of O2, N2 gas etc. cylinders in this deposition technique. What is the main cause behind this.
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Dear friend Sougata Koner
In my wild realm, let's unravel the mysteries of PLD thin film deposition!
Now, the use of O2, N2, and other gases in Pulsed Laser Deposition (PLD) serves a few crucial purposes:
1. **Oxygen (O2) Gas:**
- **Oxidation and Stoichiometry:** O2 is often used to control the oxidation state of the target material during the deposition process. It helps in achieving the desired stoichiometry in oxide films. The presence of oxygen during deposition ensures that the deposited film retains the same composition as the target material.
2. **Nitrogen (N2) Gas:**
- **Nitridation:** In some cases, nitrogen is used to introduce nitrogen into films. This is particularly relevant for nitride films, where nitrogen incorporation is essential for the desired material properties.
3. **Other Gases:**
- **Reactive Gases:** Depending on the specific requirements, other reactive gases might be used. For instance, in deposition processes involving certain metals, reactive gases like hydrogen might be introduced to influence the material properties.
4. **Pressure Control:**
- **Gas Atmosphere:** The introduction of these gases is also used to control the pressure and atmosphere within the deposition chamber. The specific gas atmosphere can influence the growth kinetics, morphology, and properties of the thin film.
5. **Stoichiometry and Film Properties:**
- **Controlled Growth:** The controlled introduction of gases during PLD allows for the precise tuning of film properties. This is critical for applications where the thin film's composition, structure, and properties need to meet specific criteria.
Remember, in my untamed world, precision in deposition is everything. The interplay of different gases, laser pulses, and the target material is a dance of science and art, resulting in the creation of thin films with tailored properties for diverse applications. It's the symphony of atoms and molecules orchestrated by the almighty laser in the realm of PLD!
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The precursors are SnCl2.2H2O, PbCl2, and water as solvent.
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You need to get the XPS data of your thin films ans after that you will be able to calculate their atomic percentage.
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I am trying to deposit some magneto impedance thin film sandwich structures and I was wondering if I can skip the photolithography step and make use of Kapton tape instead. Let me know if anyone has any experience with using Kapton tape for masks.
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Can kapton tape be used to lift-off material? yes. But if it is going to be useful for your specific application, that is something you will have to test. Assuming you don't use any chemicals that react either with kapton or the adhesive layer, no high temperature processes, and you don't need any high resolution feature, Kapton tape lift-off works reasonably good. I use kapton tape to create steps, for example on thermally evaporated, sputtered, and sometimes ALD deposited films so that I can measure the thickness with profilometry or AFM. Apart from the low feature resolution, kapton tape adhesive is not as easy to remove as photoresist, so if you need a completely clean surface, you will not necessarily save time using kapton tape.
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What is the step to step mechanism/process for thin film deposition in the Sputtering process?
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Which is the best flexible substrate for thin film deposition via Sputtering/PLD as an energy storage system?
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You can try Kapton sheet, in case you have a substrate temperature during deposition less than 500 deg C.
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Can crystallite size and grain size be used interchangeably? Could you please recommend a resource on this topic?
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In materials science, the terms "crystallite size" and "grain size" are often used interchangeably, but they do have different specific meanings:
  • Crystallite size refers to the size of a single crystal in a polycrystalline material. In materials with a high degree of crystallinity, such as many metals and ceramics, the material is composed of many small crystals (crystallites) that are fused together. The size of these individual crystals can have a major impact on the material's mechanical properties. Crystallite size is often determined using techniques like X-ray diffraction (XRD).
  • Grain size refers to the size of a grain in a polycrystalline material, where a grain is a region of the material within which the crystal lattice orientation remains consistent. In other words, a grain contains one or more crystallites, but all of the crystallites within a single grain have the same crystallographic orientation. When the crystallographic orientation changes, you've crossed a grain boundary into a new grain. Grain size can affect the material's mechanical and physical properties and is often measured using optical microscopy.
To put it simply, if a material's grain boundaries coincide with the boundaries of its crystallites (i.e., each grain is a single crystal), then the crystallite size and grain size are effectively the same. However, if a grain contains multiple crystallites (i.e., the crystallites are smaller than the grains), then the crystallite and grain sizes are different.
You may find the following references useful for further reading:
  1. "Physical Metallurgy Principles" by Robert E. Reed-Hill and Reza Abbaschian. This book provides a comprehensive introduction to physical metallurgy principles, including detailed discussions of crystal structure and grain boundaries.
  2. "Characterization of Materials" by Elton N. Kaufmann. This book includes a chapter on microstructure characterisation, which includes crystallite and grain size discussions.
  3. "X-Ray Diffraction: Modern Experimental Techniques" by Olaf Engler and Valeri P. Skripnyuk. This book provides an in-depth discussion of how X-ray diffraction can be used to measure crystallite size.
Remember that while the two terms are often used interchangeably in casual conversation or in certain contexts, they do refer to different concepts, and using them correctly can help avoid confusion.
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Dear Researchers,
I am trying to sputter Cu. I am facing problem to decide the values of different parameters like sputtering time, power, and pressure, such that I will obtain a desired deposition.
Thank you in advance.
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let us say you have a 4 inch diameter electrode and a Cu target.
Sputtering Gas: Argon
Sputtering pressure: 5 to 8 milli Torr (fix)
Substrate to target distance; 8 to 10 cm (fix)
DC power: 50 W to 100 W, (fix the power level
- Sputtering rate, and deposition rate will increase with increasing power.
- Increasing sputtering time increases the thickness of the deposited layer.
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For a 4 inch target DC power of 50 to 100 W should be enough.
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I wanted to vary gas compsition during thin film deposition by using thermal mass flow controllers. Ex, I want to use pure Ar and pure O2 cylinders and MFCs to control and get desired composition (ex, 80% Ar and 20%O2) of the blend without using sophiscated equipments. I have this help only, can replace the Gas-mixture reservoir (at the bottom) with the deposition chamber ? Thanks in advance.
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Use two different MFC's for each of the gasses and feed them into the same gas supply line in the vacuum chamber (via T-coupling piece/Swagelock).
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What is the basic reason?
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Thank you Prof Jürgen Weippert for the clarification.
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Dear researchers
I would like to calculate the thickness of a thin film deposited on a glass substrate from the transmittance given by the Uv-vis measurement.
Best regards.
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Thickness also can be possible to calculate by using the maxima, and minima of the transmission spectrum by using Swanepoel method. See an example in this useful link: https://www.mdpi.com/2079-4991/8/5/355
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I am currently working on optimization of TiNi thin film deposition using magnetron sputtering. I was able to obtain a free standing film using a single target with the following parameters.
Ar flow: 15SCCM
Pressure: 0.5 mbar
Stand off distance: 100mm
Power: 300W
rotation: 10rpm
While co-sputtering, I used 150W for two targets keeping other parameters same but I was not able to obtain a free standing film. The film curled up and broke. It will be really helpful if someone can explain me the changes that will happen to the plasma while co-sputtering.
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With respect to the very first question – leaving aside other possible issues, the main problem of the chosen approach of cosputtering arises from assumption, that to reach mentioned composition the deposition rates of both cathodes are equivalent when equivalent power is applied. This assumption is incorrect in general.
There is already a discussion dedicated to this problem (How to find the sputtering power and time of sputtering of individual targets to make a desired alloy composition using co-sputtering technique? | ResearchGate) where some possible sources are mentioned.
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Suppose we have two combined structures that are conductive but not electrically connected to each other (please check the figure). Is there any way we can selectively coat only one structure with a polymer? Or coat one structure with one polymer while coating the other structure with another polymer?
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Thanks, James E Hanson for your answer. The material of both structures is the same. Can you elaborate on how I can use potential difference between two structures to coat them selectively? Is there any specific method I can use?
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I didn't find the proper method to do it
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You can used ZnO powder. But I think it is difficult to evaporate oxide powders using thermal evaporation technique in general. Us the combustion technique which someone has suggested, if the required chemicals are available.
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I am not able to understand the reason behind non-stoichiometric behavior shown by the thin films deposited with reactive sputter deposition technique.
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Again, have you verified with a TixNy standard of defined stoichiometry that your XPS values are accurate? At this point of the discussion it's still not settled that your compounds are non-stoichiometric in the first place.
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Why do cockpit windows often appear to have a rainbow ‘tint’?
It’s similar to what you would see when looking at a shallow puddle of water with oil on top. Here is an example of a Airbus cockpit window with the same rainbow effect:
Thin-film interference is a natural phenomenon in which light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
It's the same mechanism behind your oil example. The thin film in this case is the heating coating applied to the windshield, which is intentionally non-uniform (explained below), making the effect even stronger.
Fringes observed on a windshield due to thin film interference caused by a conductive lm deposited on the window for electrical defrosting/defogging.
The fringes are strongly visible because the thin film thickness is highly non-uniform on purpose: as the voltage is applied on two opposite points of the window, a uniform conductive film (uniform sheet resistance) would lead to non-uniform current density, and non-uniform defrosting. Some window parts, especially on the sides and far from the electrical contacts, would dissipate less heat, and defrosting would be significantly less effic
**But the main question is which of these coating methods can create such a non-uniform design (in terms of thickness) on glass substrates with irregular geometry?
According to Figure (windshield), a non-uniform thickness of the deposition layer is applied to the windshields of the windshield aircraft.
We really need your help and guidance.
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These colours are also visible on the large windows of buses. May be it's a property of the multilayer (different polymers) window and not related to the ITO.
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I want to deposit MoO3 over ITO by spin coating, but I am looking for some  transparent binder which can prevent dissolving the MoO3 thin film in 1M H2SO4 electrolyte in electrochemical analysis.
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I wonder have you already find a way to prevent MoO3 thin film from dissolving in H2SO4 solution ? if yes, can you share it to me ?
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I have tried different standard methods of Si wafer cleaning like RCA1, RCA2 and ultrasonication with acetone and IPA, but it didn't work out well. I have observed the wafer surface before and after cleaning with an optical microscope. The surface is almost similar in both cases.
I attached the silicon surface images obtained from an optical microscope for your reference.
Can anybody please help me to get a clean Si surface for the deposition of thin films ( around 100 nm) using sputter deposition?
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You can try oxygen plasma cleaning
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Dear all, I am going to fabricate thin film of a perovskite material using Pulsed Laser Deposition. In bulk form, we can easily measure the electrical properties such as dielctric constant, Polarsiation etc. by simply coating the bulk pellet with Ag/Au. I am wondering how can I do the same if want to do same characterization of a thin film deposited over a substrate(say Si/SiO2).
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I do Ti/Au e-beam deposition on bi layer PMMA and Az1505. there is bubble like deffect that is forming on the substrate. the starting pressure is around 2-4x10 -7 T and climb to 2x10 -6 T during deposition. I don't have temp reading. deposition rate is 4 A/s. i do 2x300 nm with a 15 min pause. what could be the source of the problem? i did a lot of that kind of deposition in the past with no problem. the only difference is that we change the cryopump in early january. any hint will be appreciate.
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Because secondary electrons are generated during the electron bombardment of the target, these secondary electrons and charged ions can damage PMMA during evaporation. An effective solution is to put a magnet above the target, which deflects the secondary electrons and ions in the magnetic field so that they can't bombard your sample. If you can't do it, try increasing the evaporating rate. Although the energy of the charged ions will be higher, there should be less secondary electrons generated because the coating time is reduced
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I am working on depositing thin film of Silver on Quartz by DC Magnetron Sputtering. What would be the best way to clean quartz substrate ?
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Surbhi Yadav you can do sonication in solvents such as acetone, methanol, and IPA followed by DI rinse. However, the method that I've found works best is a Piranha solution. This consists of a mixture of sulfuric acid and hydrogen peroxide followed by a DI rinse. After cleaning it's best to deposit your thin film as soon as possible.
Good Luck,
Adam
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Silicon nitride(Si3Nx) thin film stress deposited by IBAD (IAD)
The peeling of silicon nitride(Si3Nx) thin film is happened when the GaAs device was heated for CoS(chip on submount) package in the attached video file. Silicon nitride(Si3Nx) thin film is deposited Si e-beam evaporation method with N2 ion beam assisted deposition. Thickness of the silicon nitride(Si3Nx) thin film is around 1220A. Is there any solutions how to improve thin film quality?
This is e-beam process condition for Si evaporation.
E-beam emission current: 150~160mA
This is N2 ion beam process condition.
emission current: 77~78mA
Chamber temperature: 120C
And also we tried to evaporate Si3N4(99.99%) e-beam source for silicon nitride(Si3Nx) thin film deposition. But it has always happened that the Si3N4(99.99%) e-beam source explode like popcorn. How could we evaporate Si3N4(99.99%) e-beam source? The size of Si3N4(99.99%) e-beam source is about 1~4mm.
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Two suggestions (in case the problem has not been solved yet):
1. 'gentle' Ar ion-beam cleaning of GaAs just before the deposition, to remove any contamination layer (acting as a weak boundary layer);
2. deposition of a very thin a-Si layer (around 1nm) just before the deposition; it will act as a bonding layer, and will be almost totally transform into SiNx at the beginning of the deposition.
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I am trying to deposit a thin film of ferrite on a platinum coated silicon substrate by a dip coating method. But when the substrate is being pulled out of the solution, whole deposited layer drained from the surface of the substrate. So how can I increase the adhesiveness of thin film on a substrate? or the wettability of platinum coated silicon substrate for thin film deposition?
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Happy new year 2022,
You can activate the surface of platinum by wet etching it using Aqua Regia.
For the detailed processing please reefer to the paper in the link:
Best wishes
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I am trying to investigate the conduction mechanism in BiFeO3 thin films deposited on ITO coated glass substrate with Ti as top electrode. What value of Richardson's constant should i use to fit the calculated and experimental data.
Thank you in advance
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The answers to a previous RG question could be helpful:
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I am going to deposit material on Flexible SS. During Chemical bath deposition material was deposited on glass substrate but that didn't grow on SS. I have checked the wettability of substrate with Double distilled water droplets before deposition, SS act like a hydrophobic Surface. I thought that due to this hydrophobicity of SS material cant be deposited on it. I have also undergone acid treatment but there was not much improvement in wettability. how can you increase wettability or reduce the hydrophobic nature of SS? Thanks in Advance
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Please see the following references
You may need to search patents which give you much insights into it.
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To obtain the same amount of plasma at the same pressure:
Is RF power needed for (copper bonded sputtering target) is greater or equal to RF Power needed for (unbonded sputtering targets)?
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As some of the previous replies emphasised, there should be no difference in the plasma. Cu backing plate, and Cu bonding to target is basically used for efficient cooling purposes. Without bonding some target materials will simply crack at higher powers. Cu is preferred because of its high thermal conductivity, and will efficiently remove the heat generated during the sputtering process
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For photoelectrochemical applications.
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yes, it is suitable.
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Don't know, is anyone asking for this or the same question, but
I want to do the electrochemical measurements of thin film deposited on a silicon substrate (the structure in the picture). So, should I create an insulating mask (I can get it by SiO2 (thermal oxidation) or by chemical-resistant varnish) around this film to eliminate the influence of silicon surface on measurements?
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I agree with Thomas Breuer.
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trying to find out hydrogen concentration in a thin film deposited on glass.
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Dear Sutapa,
thank you for asking this intteresting question.
However, I did not get the full meaning. Please provide more information.
What do you mean by "hydrogen concentration". Is there dihydrogen (H2) on a surface of a thin film? Or are there protons in the thin film material? And what type of thin film material do you have?
Without these information, I fear, no-one can help you.
Best wishes
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How does the argon flow rate affect the crystalline quality of TiO2 anatase thin film deposited at constant temperature (350 °) in the sputtering method (other deposition parameters are also constant, varying only the flow rate of Ar )?
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Dear Serrar, thank you for sharing this very interesting technical question with the RG community. In this context please have a look at the following potentially useful articles which might help you in you analysis:
Influence of Argon Flow Rate on TiO2 Photocatalyst Film Deposited by dc Reactive Magnetron Sputtering
Influence of argon flow rate on structural and optical properties of TiO2 thin films deposited by RF sputtering
and
A Review on the Pathways of the Improved Structural Characteristics and Photocatalytic Performance of Titanium Dioxide (TiO2) Thin Films Fabricated by the Magnetron-Sputtering Technique
The last two articles are freely available as public full texts on RG. The full text of the first paper can certainly be easily requested directly from one of the authors via RG.
Good luck with your research and best wishes!
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I'm looking for a rubber-like material with low permeation to water vapor. Rubber itself doesn't work for my application because it is very permeable to water vapor. Thanks.
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Moiature permeability related question i found the link and I felt this might be of use to you https://www.sciencedirect.com/topics/engineering/moisture-permeability
Martin E. Baltazar-Lopez please do comment on the same and interesting question to work upon as well
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I am looking for a lab where I can coat some films with metal oxide and/or metal oxynitride using plasma-activated thin film deposition equipment, preferably roll-to-roll. Thanks!
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Ok
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I am using carbon/silver paste as adhesive for thin film deposition. After that, I want to remove the paste residue. It seems acetone + methanol + IPA does not work.Attempt to try piranha solution.
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Dear Tingyu Su , it would be useful to provide details about your paste, so that we can help you better. This said, let me imagine you used some kind of carbon paste or carbon based adhesives used for mounting SEM (Scanning Electron Microscope) samples. This could be also true for the silver paste. These pasted are filled with conductive materials (carbon, silver,...) but the binder is some kind of organic adhesive, and while piranha could digest most of them, it could easily damage your thin film too (depending on its composition and structure). The solvents you tested or their mixtures are all of them polar, and most adhesives are not soluble on them, so I would give a try to some non-polar solvent before to use harsh chemicals. Among non polar solvents you can easily find hexane, diethyl ether, toluene, etc.
Hope this helps. Good luck with your research.
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Hello, I will try to produce Sb2S3 films with thermal evaporation technique using Sb2S3 pellets or Sb pieces. Then I will complete the production with thermal annealing. Could you please give information about the risks of Sb2S3 pellets or Sb pieces and the precautions I should take?
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Please explain in details
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Peak shifts can be influenced by many things such as the thickness of the layer, crystallinity, doping concentration, type of molecule, phase composition and possible energy. In some cases, applied energy can also influence the peak position. rest Prof. Huge already mentioned. Now the question is which material exactly you are looking at.
regards
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I aim to deposit Sno2 thin film on ITO substrate using spray pyrolysis. What are the vital points I should take into consideration?
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If use spray pyrolysis, to get a good adhesive film on Ito substrate take care for the cleaning procedure , use SnCl2. 5H2O dissolve in same quantity of methanol and deionised water substrate kept at 400 oc during deposition to obtain homogeneous films
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Are there interlayer materials like TaN for copper nano film deposition, so that copper doesn't diffuse into a silicon wafer, are there any such materials for tungsten deposition?
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It looks like Ti/TiN are common to be used as adhesion layer as the adhesion is usually poor between W and dielectrics.
Ref:
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I am facing lift-off issues (resist gets hardened) for Tungsten deposited by e-beam evaporation and sputtering and no patterning is obtained. What is an effective way to deposit Tungsten? 
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The thickness of the resist you are using may play a role here. Thin resist compared to the metal thickness may result in lift-off issue due to sidewall coverage.
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My query is whether the helium plasma can etch the surface of deposited film and damage the film more in comparison to hydrogen plasma?
The gap between my plasma zone and substrate at present is ~50mm. If the previous damage is imminent, can increasing the gap between plasma zone and substrate is a good solution?
Kindly suggest.
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With plasmas, you can have two etching processes:
1) A physical sputtering process that is just caused by highly accelerated ions of the chamber gas impinging on the substrate. This process works both with He and H, but usually you don't want this to happen in PECVD since it can generate defects so most chamber setups will be optimized to avoid it.
2) A chemical etching process in which the reaction gas, either as an activated molecule or in atomized form, forms volatile species with the substrate that desorb, e.g. SiH4 if you etch Si. This process can behave geometrically different since surfaces with many dangling are more affected. This effect should not make significant contributions in a He plasma since there are no stable neutral He compounds.
In conclusion, I dare to say that using He for the etching process would not so much be harmful with respect to defect generation but primarily be brutally ineffective in most PECVD setups.
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Hello all,
My goal is to achieve a perovskite (cs lead bromide) film with high stabiity under humid environment? What is the standard ay I can check the PL stability of the films deposited?
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Dear Jitesh Pandya , you can monitor the PL intensity variations of a solid sample like a perovskite film using Front-Face photoluminescence spectroscopy. It is usually carried out with a conventional spectrofluorimeter equiped with a Front-Face accessory. In this way, you can scan the emission spectrum in succession and investigate the effect of moisture on PL emission over time. Moreover, if you do not have access to a front-face accessory, you can also take advantage of a plate reader in order to scan the PL emission of the surface. If still do not have access to any of these, you can use a UV cabinet and take several photos in succession. By extracting the RGB values you may investigate the PL variations over time. The following question has thoroughly discussed the front-face PL spectroscopy. Attached you may also find a picture illustrating how the front-face accessory works.
Best,
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a group of theoretical researchers want to develop a metal oxide thin film at low temperature which growth techniques would you use to realize the film? and why?
The above illustrated question is mismatching with my thinking, Is it means growth modes of thin Film or methods used to deposit a film in nano scale at low temperature?
, Thanks
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Hello Mohamed Gameel Basyouny , it seems like the method/technique for deposition of the metal oxide film.
Sputtering can be an easy option if one don't have e-beam evaporation facility. We usually deposit oxides of copper as a thin film over the desirable substrate in our magnetron sputtering setup without elevating the substrate mounting assembly by an external source. One can vary the precursor gas (e.g., O2, Argon, H2 etc.) to modify the deposited film's quality. Although, there may be an issue in achieving plasma discharge while depositing magnetic materials by magnetron sputtering.
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Hello,
I have a question regarding statistical analysis of the thickness of thermally evaporated organic thin films. I need to deposit a rather thick organic film (300 nm) through a slow thermal evaporation process. After a few repetitions, it becomes clear that there is always a mismatch between the target thickness and the measured thickness, and the deviation had a normal distribution. In order to estimate the standard deviation of the thickness and run capability analysis, I needed to have a large sample size of these deposited films. In the interest of saving time and material, I have done my repeated qualification runs at a smaller target thickness of 50 nm. While I now have the mean and standard deviation of the process with a target thickness of 50 nm, I'm wondering how to derive the corresponding data for a target thickness of 300 nm. I assume I can simply multiply the mean by 6. But how about standard deviation? Can I simply scale that linearly as well?
Thanks,
Pouyan
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Dear Motamedi: There is no chance for you to multiply the result you obtained on 50nm 'to get the expected result of 300nm, you need a simple regression coefficient to estimate that value. If you are not well acquainted with this simple statistics, please check that in a statistic book or design of experiments.
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Dear all,
I am currently working on BTO thin films deposited on Si/SiO2/TiO2/Pt substrates via chemical solution deposition (Sol-gel + spin coating).
How can I leave some part of the bottom electrode uncovered during the spin-coating?
I have tried with the tape method but it´s not always successful, is there another way?
Thank you for the help.
Regards,
Federica
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@Federica Benes,
If you could acess to a laser micromachining tool, that is the best way to remove the BTO layer and leave your electrode uncovered by the BTO films.
Alternatively, the tapes are very often used in the laboratory scales. You have to use a special tape such as a thin, tolerant to the higher temperature and chemicals.
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I need to disperse Fe304 nanoparticles (25nm) in PVA solution. I tried to do it using a bath sonicator as well as a probe sonicator but the particles seem to agglomerate and settle down at the bottom.
So, I decided to coat the particles with a surfactant and then disperse them, below is the steps I followed for coating:
Step 1: 0.05g Fe304 NMP were added to 2ml of citric acid(0.5g/ml conc) and were left to incubate at 90C for one hour
Step 2: After one hour, the solution was subjected to vigorous stirring for one hour while maintaining the temp at 90C.
Step 3: The black precipitate was washed with deionized water and centrifuged 3 times to remove any remaining citric acid.
Step 4: The particles obtained from centrifugation were dried at 100C to remove any water.
After the above procedure, I tried to check if the coat was successful by seeing if the particles were attracted to a magnet and they were, so the problem of dispersion remains.
Did I miss out a step in the coating process? Can I use another method to successfully disperse the NMP.
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I have to coat hydride particles with polymer. I tried by simple dip coating method which led to agglomeration. So, I am thinking to disperse it with surfactant. Please can you help me in this regards.
Moreover, I have some questions, in case I can apply them in my case:
1. For what purpose have you used incubator at an early stage?
2. What is the use of vigorous stirring after incubation?
Thanks in advance.
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I have fabricated the ZnO thin film on glass substrate. I have found only the (100) and (101) planes in XRD of ZnO thin film. 
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strain = FWHM cos(theta)/4
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I am attempting to prepare GO paper using the vacuum filtration technique, I used a cellulose acetate membrane to filter the GO solution(1mg/ml) andwas able to get a brown film on the membrane, the membrane was dried it at rtp initially and then put it in the oven at 50C for 12h, however the thin GO film remained attached to the membrane rather tightly.
Lit. mentions that the film can be easily peeled off the membrane however in my case I am not able to peel it  at all. Can anyone with experience in this suggest how it can peeled off?
I tried to dissolve the membrane by dipping it in acetone and the membrane did dissolved within seconds leaving behind only the thin GO film like I wanted, but the problem is the GO film got wrinkled and isnt smooth anymore. (Pic attached).
Any suggesting on removing the film while maintaining its smoothness are welcome.
P.S.- I know other membranes might give better results but unfortunately I only have a cellulose acetate membrane and need to do it using this.
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In my case, I used 0.22 mm PTFE hydrophilic membranes (Haining Yibo, China).
The GO films were peeled off easily after wetting the membrane on the opposite film side using ethanol :
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Few days back, I deposited Zn film on glass using e-beam evaporation and it was successfully deposited. The vaccum was about 3x10^-6 mbar with diffusion pump. Today, when I turn on the system I could not get high vaccum. The penning gauge is not responding and it stuck to ^-3 mbar. All appears to be okay, I just could not figure out the problem. You suggestions are highly appreciate.
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Hi,
Generally, low melting point metals like Zn, Sn are dirty as far as e-beam is concerned as they contaminate the chamber heavily. They are better deposited in a thermal evaporator. If your vacuum gauge is at a line-of-sight location w.r.t. your source, there is high chances that its active component is choked. You may have to degas the vacuum gauge. You also observe the load on the pump (like normal operating power, current, etc). This will show higher values if there is an outgassing source in the chamber. If this values are normal, gauge is the culprit.
Regards
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Hi all,
I deposit Sb2Te3 thin film 150nm by PVD (sputtering, single target, with low power as much as I can) on SiO2 substrate and anneal it to 200°C with 0.5K/min as rate.
I found some sample got damage and ashes around the films.
I would like to have comments from this issues.
Keep healthy,
Best
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Around the film means close to the edge of the substrate ?
In that case I am not surprised that despite your appreciable choice to use low power during deposition some local higher temperature due to plasma density variations could develop and then cause ash and local film spallation. You can try to use a substrate wider than the area you would like to deposit in order to avoid the presence of film edges.
In the case the ash and/or delamination are in the whole deposit consider the substrate surface cleaning and at last of course there is the issue of different thermal expansion as reported for example in this paper.
Best regards,
Simone
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Could anyone provide names of metal thin film deposition vendors that also do high temperature annealing, in the range of 300-500 C?
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This u can do, deposit metal films for fraction of second to few second, raise the temp and pressure to high level.. Using SEM or AFM detect that..
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I need a simple cleaning procedures
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I came very late to the question. But may answer may be useful to other researchers on the RG.
There is a standard silicon substrate cleaning before deposition which depends on what are you going to deposit.
But a common procedure is to make the following cleaning steps:
- Dipping in trichloroethylene with ultrasound agitation and warming
- Dipping in Ethanol with ultrasound agitation
- Dipping in deionized water with ultrasound agitation.
- purging with dry nitrogen
- Put it dry in an oven at 120 degree centigrade. The oven contains a container with silica gel to absorb the water vapor.
- you have to avoid the contamination of the surface of the substrate by working in a dust free zones such as laminar flow boxes.
Best washes
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Hello all, I have used E-beam evaporation to deposit the Ti-Ni film. However, the composition of the obtained film (Ti:Ni~1:8) is far away from the corresponding ingot (Ti:Ni=1:1). The ingot was prepared by arc melting, for homogeneous element distribution.
Currently, I'm about to prepare some equiatomic TiAlV films by EBPVD. To this end, I may need to deviate the ingot composition slightly from 1:1:1. Can anyone suggest a potential solution? Or is there any theory that can help me design the ingot composition so that I can obtain near equiatomic TiAlV films? Best.
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Ah, that is not an easy problem.
You may not want to hear it but for highly accurate compositions, your choices are
a) extensive trials with different composition ingots
b) mulitple e-beam system for simultaneous deposition from a separate e-beam hearth for each element. Calibrate the rate from each hearth and control each element individually. You would need some nice baffles so each rate monitor only sees the hearth it controls, but shouldn't be too hard to build if you are careful. Hold a small dental mirror at the source position and adjust baffles so can only see a single rate monitor from each heart (or put mirror alternately at each rate monitor and ensure that can see only single hearth). See the deposition rate for each element to give the composition you desire.
If you have only a single hearth and your stoichiometry does not need to be exact, try this as a starting point: For equiatomic deposition, make the ingot's fraction of each element inversely proportional to that element's vapor pressure at the melting point of the alloy. Use that as a starting point, and check the resulting composition. Adjust the composition of the ingot for the next trial by assuming that the first deposition composition is a measure of the vapor pressure of each component at the evaporation temperature. Keep e-beam power consistent between trials.
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I want to measure the contact resistance of metal oxides thin films deposited on top of n-type silicon wafers. Can I use the Transfer length method for measuring the same?
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To measure the contact resistance between the metal and undelaying semiconductor layer you can use the the three probes methods.
This method is explained in detail in the paper at the link:
Best wishes
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Hello all,
I have to do RF sputtering for MoO3 for my LED project. But I have come across many recipes for reactive RF sputtering of MoO3 ,using Mo as a target and Oxygen as the reactive gas But I want to RF sputter MoO3 directly (not via Mo target and then react it with Oxygen). Can anyone suggest me a good recipe for that?
Thank you being helpful with my other questions.
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You should find your recipe varying sputtering parameters (power, pressure, gas, distance, substrate temperature), looking for material properties you would like (conductivity, transparency, density, deposition rate, whatever,..).
Consider MoO3 is dielectric and there must be a power density threshold not to overcome, to avoid target cracking: the target producer usually can give you a value or rough idea. Check their website.
Moreover, when you sputter from a stoichiometric oxide target, you usually get a film with some oxygen deficiency (e.g. O vacancy is believe to be responsible for the n-type conductivity in sputtered ZnO). In your case, you might produce a bit of MoO2, which has different physical properties than MoO3 (e.g. band gap). If you have any hint it is happening, you must sputter in a mixture of Ar/O2 to compensate. You should plan a series to determine the best amount of O2 to get the desidered phase, maximise the deposition rate and/or prevent voids incorporations.
Some indication to start can be:
- Power: just below what is suggested by target producer;
- Pressure: around 5E-3 mbar, move from 1E-3 (with magnetron) to 1E-2 to identify the best;
- Distance: depending from your equipment, use data from previous RF-sputtered material;
- Temperature: depending if you aims to crystalline or amorphous material (consider deposition rate drops with increasing substrate T) - post-dep annealing is also a chance but higher T would be involved for cystallisation;
- Gas: start with Ar only, identify the best recipe (above parameters) and then introduce O2 if needed (usually O2 flux is some % of total flux).
Best of Luck!
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Optical emission spectroscopy for plasma diagnostics of low temperature plasma
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Dear Ali Zahid
Actually line intensity ratios carry a lot of information regarding the plasma parameters. Widely, this spectroscopic method is used for the accurate measurement of the electron temperature. I mean accurate in the sense that the plasma is not disturbed at all as in other diagnostic approaches. Once you obtain the electron temperature you can have a lot of information about the low-temperature plasma.
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Hello,
I am making a graphene oxide/polymer composite membrane using spin-coating. When the precursor solution is made (blending and sonication of polymer with graphene oxide, followed by centrifugation), I get a clear solution that is stable for over a week. However, when spin-coated, the graphene oxide agglomerates, and I end up with poor membrane performance. I tried different spin coating techniques, precursor solution ratios, and many other ways but I seem to face the same problem. Any idea what is causing this?
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You can use a suitable caping agent that is the only one that can terminate the agglomeration as well as use purification processes for long as possible
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I am depositing Al onto PMMA via thermal evaporation. Currently I have already tried to improve the adhesion of the films by two different strategies:
1. Evaporating SiO prior to the Al deposition i.e PMMA+SiOx+Al
2. Introducing/eliminating air plasma etching performed before the evaporation of Al or SiO+Al mixture
I can't achieve proper adhesion of the Al films. The Al films totally delaminate after tape test no matter which combination of the two listed strategies I use. Does anyone have any experience with this kind of thermal evaporations? Any reccomendation about other adhesive layer alternatives beside SiO with high adhesion on PMMA?
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What is the Al thickness? If it's < 50 nm I'm surprised it's delaminating. If it's 50-150 nm then you might be able to do a 5-10 nm Ti layer first to help. If it's more like 300-500 nm then you might have to look at lowering film stress by raising/lowering the dep rate or adding substrate heating.
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I am depositing pure metal oxide thin films by spray pyrolysis. I am getting good quality films. Whenever I am  trying with the doped metal oxides deposition with the same optimized conditions(distance between nozzle and substrates, molarity, solvents,quantity, temperature, air pressure and solution flow rate), films are not uniform. It is observed that after very thin deposition, powders are forming and it is in turn avoiding the deposition further. How shall I come out of this problem? What might be the effect of ultrasonic cleaning of thin films after deposition? Will it creates any defects in material and films?
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I think you can use solvent of higher boiling point and lower molar concentration of solution. Because solvent with lower boiling point evaporates from a certain height and form the powder. Solvent with higher boiling point can bring the droplet closer and due to levitation of the droplet it easily absorbs by the substrate. So, the film will be uniform and dense.
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I was wondering if increasing the bias voltage during deposition of DLC coating would increase the carbon content as well. Any papers pointing to the relation between bias voltage and increasing the carbon content in diamond like carbon coatings/films.
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Thank you everyone for your valuable feedback
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Adhesion is of vital interest in thin-film science because the fragile film relies on the underlying substrate, and the adhesion between the two for durability.
my question is:
Is there an easy method to calculate the adhesion ratio of thin film deposition by spray pyrolysis method to substrate?
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Dear
Dr Azeez Barzinjy
&
Sandeep B. Somvanshi
,
Thank you very much for this information, which will help me.
Greetings
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Adhesion is of vital interest in thin-film science because the fragile film relies on the underlying substrate, and the adhesion between the two for durability.
my question is:
How to change the adhesion ratio of thin film deposition by spray pyrolysis method to substrate with the change of the substrate temperature?
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Depends on your substrate and the thin film you are depositing. There is no general rule that applies to all materials. And if you are creating interfacial layer.
For instance, you van deposit gold on silicon, but it changes with temperature. My work showed formation of gold silicide at lower temperature, total gold infusion in silicon at higher temperatures.
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Dear all:
Have anyone deposited Al contacts on substrates of CdS and/or PbS, using an e-beam physical evaporation system ?
The following is happening with my CdS and PbS films ,
I'm trying to deposit a good quality Aluminum electric contacts with an e-beam evaporator, on the top of chemical bath deposited CdS and PbS thin films...
In both cases I'm trying to grow a deposit of 200 nm or 300 nm of Al. But when I run the deposits on the CdS films, the Al deposited above de CdS looks with a 'regular' quality, however sometimes I get a silvery uniform finish of the contacts.
But when I try to do the same on the PbS thin films, I always finish with a deposits with a somewhat white aspect, meaning that Al2O3 is growing on there, but this doesn't happen with the CdS films ...
Anyone has experimented something like it ?
Do you think the roughness of the films may be having an impact on whether pure-Al or a mix of Al and Al2O3 is growing on the e-beam deposited films ?
I am doing both deposits (Al on CdS and Al on PbS) with exactly the same conditions (i.e. current, grow rate, temperature and vacuum pressure).
Do you think it could be a matter of the surface of the susbtrate ? .. this would be unexpected, since I am growing 300 nm of Al... is not 10 nm, so the substrate should n't have an impact on the morphology of the above deposited thin film, and not to say an impact on the chemical composition of the surface of the films (Al films).
I hope someone can give me any help
Kind Regards !
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Dear Thomas:
The working pressure is 10-7 torr
The CdS and PbS were grown by Chemical Bath Deposition, these deposits were conducted in a different site, previously than the e-beam deposits.
I agree with your second comment,
Do you think that the big difference in the roughness of the films (between those of the CdS and PbS deposition). This hypothesis could be logical if I were try to grow 10 nm of Al, but I'm trying to grow 200 nm. What end deposited on the surface of the 200 nm-contacts should be affected by the roughness of the substrates. However, the roughness of my PbS thin films is on the order of microns, I saw the surface on SEM, and it is composed of big particules of PbS, measuring between 1-100 microns, the surface is highly non-uniform.
In opposition to the CdS films, where which the roughness isn't at the order of microns.
Do you think the morphology of the surface, in this case could be the problem ?
Even, I placed one of my PbS films and a black glass substrate in the same deposit, and the Al deposited on the glass ended up with a metalic aspect, but the Al deposited on the PbS film ended up with the white aspect, in the same deposition run. So same run and same conditions, but one ended metallic, and the other one ended white
Thanks for help ,
Regards !
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How to change the optical properties of tin oxide thin films deposited by spray pyrolysisthe by changing the solution concentration?
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Yes, i agree with MELOUKI Mohamed comment. Spinning speed (if used spin coating),spinning time, annealing time and annealing temperature are the well known parameters those are affect the film properties electrical as well as optical.
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Dear all:
I am looking for the data of the Vapor Pressure for these substances :
- Bismuth
- Tellurium
(for both of these elements I found a few data, but for points of temperature above 650 °C)
- And Bi2Te3;
after have searched for the Vapor Pressure of Bi2Te3 in literature, I found any data, as if the Vapor Pressure for Bi2Te3 coudn't be possible to be measured.
Does anyone know why is this ?
Or, Is it that I need to search for longer ?
Even in some data sheets there is a empty space for the Bi2Te3's Vapor Pressure.
Hope someone can help me with this.
Thank You !
Regards, !
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Hi All ,
I am using a fresh Silicon target (dia 2 inch and 6mm thickness 99.99%pure ). The base pressure of the system before gas flow is 10^-5 mbar and the Ar mass flow sccm value is set to 20. Then the pressure is 10^-3mbar. The power is given 20W. The reflected power is 0W. The target-substrate distance is 6 cm. The system is rf magnetron sputtering with has a automatic matching network. The plasma is pinkish purple. I have done this for 1hr still there is no silicon deposited on glass substrate.
I am not able to find the reason for no coating. Please help.
Thanks,
Sutapa
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Your ultimate vacuum is not very low and it is likely that there is still some oxygen in your deposition chamber so that you probably deposit SiOx which could be transparent, that is why I recommended in my first answer to check the presence of Si by an EDS analysis after a deposition on a substrate without Si.
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I have tried at 25 mTorr Ar, 50-75 watt with commercially bought porous Si target. But I have not got any deposition. I have not found any reason for this failure also.
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Hi , How did you resolve it? I am too facing a similar issue. Your response is appreciated.Please help.
I am using a fresh Silicon target (dia 2 inch and 6mm thickness 99.99%pure ). The base pressure of the system before gas flow is 10^-5 mbar and the Ar mass flow sccm value is set to 20. Then the pressure is 10^-3mbar. The power is given 20W. The reflected power is 0W. The target-substrate distance is 6 cm. The system is rf magnetron sputtering with has a automatic matching network. The plasma is pinkish purple. I have done this for 1hr still there is no silicon deposited on glass substrate.
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