Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society (J VAC SCI TECHNOL B )

Publisher: American Vacuum Society, American Vacuum Society

Description

The Journal of Vacuum Science and Technology B is devoted to reports of original research, review articles, and Critical Review articles. The JVST B has been established to provide a vehicle for the publication of research dealing with microelectronics and nanometer structures. The emphasis will be on processing, measurement and phenomena, and will include vacuum processing, plasma processing, materials and structural characterization, microlithography, and the physics and chemistry of submicron and nanometer structures and devices. The journal also publishes papers from conferences and symposia that are sponsored by the AVS and its Divisions. JVST B is published six times annually (Jan/Feb, Mar/Apr, May/Jun, Jul/Aug, Sep/Oct, Nov/Dec).

  • Impact factor
    1.36
    Show impact factor history
     
    Impact factor
  • 5-year impact
    1.29
  • Cited half-life
    8.80
  • Immediacy index
    0.27
  • Eigenfactor
    0.02
  • Article influence
    0.44
  • Website
    Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures website
  • Other titles
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, Microelectronics and nanometer structures, Journal of vacuum science and technology., JVST B
  • ISSN
    1071-1023
  • OCLC
    23276603
  • Material type
    Periodical
  • Document type
    Journal / Magazine / Newspaper

Publisher details

American Vacuum Society

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • On a public eprint server
    • On authors and employers website
    • Publisher's version/PDF may be used, on authors and employers website only
    • Must link to publisher abstract version
    • Published source must be acknowledged (see policy for wording)
    • If funding agency rules apply, authors may post articles in PubMed Central 12 months after publication
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors studied the influence of isotopes on the Ar/H2 and Ar/D2 plasmas using Langmuir probe and ion mass analyzer measurements at several pressures relevant to low temperature plasma surface processing. As up to 50% H2 is added to Ar plasma, electron energy distribution functions show an increase in electron temperature (from 2.5 eV to 3 eV for 30 mTorr with 50% addition) and a decrease in electron density (2.5 × 1011 cm−3 → 2.5 × 1010 cm−3 at 30 mTorr with 50% addition). At lower pressures (5 and 10 mTorr), these effects are not as pronounced. This change in electron properties is very similar for Ar/D2 plasmas due to similar electron cross-sections for H2 and D2. Ion types transition from predominantly Ar+ to molecular ions ArH+/H3 + and ArD+/D3 + with the addition of H2 and D2 to Ar, respectively. At high pressures and for the heavier isotope addition, this transition to molecular ions is much faster. Higher pressures increase the ion–molecules collision induced formation of the diatomic and triatomic molecular ions due to a decrease in gaseous mean-free paths. The latter changes are more pronounced for D2 addition to Ar plasma due to lower wall-loss of ions and an increased reaction rate for ion–molecular interactions as compared to Ar/H2. Differences in plasma species are also seen in the etching behavior of amorphous hydrocarbon films in both Ar/H2 and Ar/D2 plasma chemistries. D2 addition to Ar plasma shows a larger increase in etch rate than H2 addition.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 07/2014; 32(5):041206.
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    ABSTRACT: Graphene-insulator-graphene vertical tunneling structures are discussed from a theoretical perspective. Momentum conservation in such devices leads to highly nonlinear current-voltage characteristics, which with gates on the tunnel junction form potentially useful transistor structures. Two prior theoretical treatments of such devices are discussed; the treatments are shown to be formally equivalent, although some differences in their implementations are identified. The limit of zero momentum conservation in the theory is explicitly considered, with a formula involving the density-of-states of the graphene electrodes recovered in this limit. Various predictions of the theory are compared to experiment.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 04/2014; 32(4).
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    ABSTRACT: Formation of unique shapes and geometries was obtained by evaporation of platinum onto a polycrystalline graphite foil. This study was done using scanning electron microscopy, atomic force microscopy, and photoelectron spectroscopy. The evolution of complex nanostructures was observed for various amounts of Pt deposition, and the observed structures were discussed in terms of the average fractal dimension. The fractal dimension was found to increase with increasing deposition of Pt and was found to be in the range from 1.2 to 1.6 in the submonolayer coverage regime as investigated. The changes in the average fractal dimension were correlated with the corresponding changes of the average size and width of the branches of the structures. A logarithmic dependence of the average size of the deposited structures on corresponding amount Pt deposited was found.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 03/2014; 32(3).
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    ABSTRACT: Silicon nitride (SiNx) thin films were deposited on (100) Si wafers in a molecular-beam epitaxy growth chamber equipped with a customized multipocket electron-beam evaporator, a Si effusion cell, and an RF plasma source for reactive nitrogen. The films were characterized using atomic-force microscopy, spectroscopic ellipsometry, and specular x-ray reflectivity. For films deposited using an electron-beam Si source with N/Si > 1.33, the deposition temperature determined the density and refractive index. Stoichiometric Si3N4 films were produced when the deposition temperature was greater than 725 °C, in agreement with our previous results that used an effusion cell for Si. By using the electron-beam Si source, an order of magnitude increase in SiNx deposition rate was achieved over the conventional effusion cell method.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):02C117-02C117-5.
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    ABSTRACT: Alloying bismuth with InAs provides a ternary material system near the 6.1 Å lattice constant, which covers the technologically important mid- and long-wavelength infrared region. One challenge for this material system is that it is not straightforward to incorporate bismuth into the bulk InAs lattice, since bismuth has a tendency to surface-segregate and form droplets during growth. In this work, the conditions for InAsBi growth using molecular beam epitaxy are explored. A growth window is identified (temperatures ⪞ 270 °C, V/III flux ratios 0.98 ⪝ As/In ⪝ 1.02, and Bi/In ≅ 0.065) for droplet-free, high-quality crystalline material, where InAsBi layers with compositions of up to 5.8% bismuth (nearly lattice-matched to GaSb) are attained. The structural quality of InAsBi bulk and quantum well samples is evaluated using x-ray diffraction and transmission electron microscopy. The optical quality is assessed using photoluminescence, which is observed from quantum well structures up to room temperature and from thick, low Bi-content bulk layers at low temperatures. Bismuth is also used as a surfactant during the growth of InAs/InAsSb superlattices at 430 °C where it is observed that a small bismuth flux changes the surface reconstruction of InAs from (2×1) to (1×3), reduces the sticking coefficient of antimony, results in a slight increase in photoluminescence intensity, does not significantly incorporate, and does not alter the surface morphology.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):02C120-02C120-9.
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    ABSTRACT: The production of spurious dangling bonds during the hydrogen depassivation lithography process on Si(100)-H is studied. It is shown that the number of spurious dangling bonds produced depends on the size of the primary pattern on the surface, not on the electron dose, indicating that the spurious dangling bonds are formed via an interaction of the liberated hydrogen with the surface. It is also shown that repassivation may occur if hydrogen depassivation lithography is performed near an already patterned area. Finally, it is argued that the product of the interaction is a single dangling bond next to a monohydride silicon on a silicon dimer, with a reaction probability much in excess of that previously observed.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):021805-021805-4.
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    ABSTRACT: The authors have measured and compared the stress in nickel silicide full sheet layers prepared with added platinum on (001) p-type Si wafers by using either a rapid thermal anneal (RTA) at 390 °C or a millisecond submelt laser dynamic scanning anneal (DSA) at 800 °C. The room temperature tensile stress of the silicide annealed with DSA is 1.65 GPa, whereas that of the silicide annealed with RTA at 390 °C is 800 MPa. Our analysis confirms that the origin of the stress lies in thermal expansion factors. Despite some small variations, the stress remains highly tensile in both layers after a 1 h post-treatment at 400 °C, with values of 1.4 GPa and 850 MPa for the DSA and RTA samples, respectively. The authors also performed strain measurements with dark field electron holography in the source drain region of 28 nm field complementary metal oxide semiconductor field effect transistors, under the silicide dot. They then determined the stress inside the silicide by combining the strain measurement with finite element mechanical simulations; values of 1.5 GPa and 600 MPa were found at the nanometer scale for the DSA and RTA samples, respectively, which are consistent with the macroscopic observations.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(1):011211-011211-6.
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    ABSTRACT: Si3N4 spacer etching processes are one of the most critical steps of transistor fabrication technologies since they must be at the same time very anisotropic to generate straight spacer profiles and extremely selective to silicon in order to minimize the silicon consumption in source/drain regions. Minimizing the silicon recess and ion-induced damages to silicon surfaces are key criterions for fully depleted silicon on insulator technologies in order to ensure a high surface quality for the subsequent step of silicon epitaxy. In this work, the authors investigate synchronously pulsed CH3F/O2/He plasmas for the etching of Si3N4 spacers selectively toward Si (the selectivity typically relies on the oxidation of the silicon layer). First, they compare the Si3N4 and silicon etch rates measured in continuous wave (CW) plasmas, while varying the [CH3F]/[O2] ratio, to the etch rates measured using pulsed plasmas. Using angle resolved x-ray photoelectron spectroscopy and scanning transmission electron microscopy (STEM) cross sections, they show that the silicon thickness oxidized during the Si3N4 etching decreases from 1.5 nm in CW to 0.5 using a plasma pulsed at 1 kHz and 10% duty cycle, and the percentage of carbon implanted into the silicon substrate is reduced by a factor 2 using pulsed plasma conditions. Moreover, STEM cross sections show an improvement of the spacer profile when the plasma is pulsed at 1 kHz and low duty cycles, with a rounded spacer top leading to a better gate encapsulation, instead of the faceted spacer obtained using CW plasma conditions.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):021807-021807-8.
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    ABSTRACT: The authors report on the growth of InAs/GaAs quantum dots lasers on silicon emitting in the 1.3 μm wavelength regime with p-doped active regions. A growth optimization procedure guided by a combination of high and low excitation photoluminescence is presented for the InAs quantum dot growth. Growth conditions derived from this procedure are used to produce high optical quality quantum dots embedded in a GaAs/AlxGa1−xAs graded index separate confinement heterostructure waveguide. Ridge waveguide lasers fabricated from the as-grown material achieve room temperature continuous wave lasing at low thresholds, with high output power and elevated T0.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):02C108-02C108-4.
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    ABSTRACT: Grayscale electron beam lithography is an important technique to manufacture three-dimensional (3D) micro- and nano-structures, such as diffractive optical devices and Fresnel lenses. However, the proximity effect due to the scattering of electrons may cause significant error to the desired 3D structure. Conventional proximity correction methods depend on the exposure energy distribution which sometimes is difficult to obtain. In this study, the authors develop a novel proximity effect correction method based on multivariate adaptive regression splines, which takes exposure energy and development into consideration simultaneously. To evaluate the method, a Fresnel lens was fabricated through simulation and experiment. The measurements demonstrate the feasibility and validity of the method.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(3):031602-031602-7.
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    ABSTRACT: Grain boundaries in the polycrystalline microstructure of post-annealed high-κ (HK) dielectrics are a major limitation in the reliability of HK dielectrics used for advanced CMOS technologies. Another challenge in the field of HK dielectrics is to ensure higher drain drive current in CMOS, while maintaining low leakage current. In this work, the authors demonstrate enhanced performance of HfO2 and CeO2 dielectrics by incorporating lanthanum. The resulting stacks show promising dielectric characteristics with reduced leakage current and uniform (amorphous) crystal structure. The improved HK characteristics were shown to occur even over nanometer-length scales using scanning probe microscopy and transmission electron microscopy, in agreement with previous studies based on micron-scale device-level measurement.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(3):03D125-03D125-7.
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    ABSTRACT: The effect of rapid thermal annealing on the optical and structural properties of GaAsBi/GaAs quantum wells (QWs) is investigated. The photoluminescence (PL) spectra of the samples are measured at 80 K and room temperature before and after rapid thermal annealing, to ascertain any improvement in the optical quality of the material. The impact of annealing temperature on QW interface quality, layer composition, and thicknesses are studied with x-ray diffraction. For a 60 second annealing time, the low temperature peak PL intensity increases to a maximum of 1.8 times the original intensity at an annealing temperature of 500 °C. Validating this optimum annealing temperature, the room temperature PL peak intensity is seen to increase by 2.2 times. The peak position exhibits a minor blueshift of 15 meV throughout the 450–700 °C temperature range, while annealing at 750 °C produces a blue-shift on the order of 100 meV, indicating out-diffusion of bismuth from the QW. Degradation of the QW interfaces with annealing temperatures above 550 °C is observed. The composition and thickness of the QWs remained constant up to 700 °C. Significant out-diffusion of bismuth and QW thinning are observed at an annealing temperature of 750 °C.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(2):02C119-02C119-5.
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    ABSTRACT: Two series of ultrathin high-k samples (mixed layers HfxAlyOz and bilayers HfO2 on Al2O3) prepared by atomic layer deposition were investigated using spectroscopic ellipsometry in the energy range of 0.7–10.0 eV. The (effective) optical gap of both mixed layer and bilayer structures can be tuned by the film composition. The optical gap of mixed layers is linearly dependent on the Hf fraction from 5.77 (±0.02) eV for pure HfO2 to 6.71 (±0.02) eV for pure Al2O3. The effective absorption gap of bilayers measured in reflection geometry is lower than that of mixed layers with a comparable Hf fraction due to the dominant effect of the top layer. An increase in film thickness as well as a decrease in refractive index and gap energy was observed after sample storage for two months in atmosphere. The aging effect is likely due to further oxidation of the oxygen deficient high-k films caused by the oxygen diffusion from air into the films.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(3):03D115-03D115-4.
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    ABSTRACT: Nanolaminates comprising of TiO2 or HfO2 sublayers within an Al2O3 matrix are grown with atomic layer deposition. These nanolaminates provide an improved silicon surface passivation compared to conventional Al2O3 films. The physical properties of the nanolaminates can be described with a dynamic growth model that considers initial and steady-state growth rates for the involved metal oxides. This model links the cycle ratios of the different atomic layer deposition precursors to the thickness and the material concentrations of the nanolaminate, which are determined by means of spectroscopic ellipsometry. Effective carrier lifetime measurements show that Al2O3-TiO2 nanolaminates achieve values of up to 6.0 ms at a TiO2 concentration of 0.2%. In Al2O3-HfO2 nanolaminates, a maximum effective carrier lifetime of 5.5 ms is reached at 7% HfO2. Electrical measurements show that the TiO2 incorporation causes strong hysteresis effects, which are linked to the trapping of negative charges and result in an enhanced field effect passivation. For the Al2O3-HfO2 nanolaminates, the capacitance data clearly show a very low density of interface traps (below 5·1010 eV−1·cm−2) and a reduction of the fixed charge density with increasing HfO2 concentration. Due to the low number of recombination centers near the surface, the reduced field effect passivation only had a minor impact on the effective carrier lifetime.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2014; 32(3):03D110-03D110-6.

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