Bruno La Fontaine

Bruno La Fontaine
Hermes Microvision Inc | HMI · Technology Development

Doctor of Philosophy

About

139
Publications
15,943
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,415
Citations
Citations since 2017
2 Research Items
378 Citations
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080
Introduction

Publications

Publications (139)
Article
Extreme ultraviolet (EUV) lithography is expected to succeed in 193-nm immersion multi-patterning technology for sub-10-nm critical layer patterning. In order to be successful, EUV lithography has to demonstrate that it can satisfy the industry requirements in the following critical areas: power, dose stability, etendue, spectral content, and lifet...
Conference Paper
This paper describes the development of a laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source for advanced lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193nm immersion double patterning technology for sub- 20nm critical layer patterning. In this paper we discuss the most recent results from...
Conference Paper
Laser produced plasma (LPP) light sources have been developed as the primary approach for EUV scanner imaging of circuit features in sub-20nm devices in high volume manufacturing (HVM). This paper provides a review of development progress and readiness status for the LPP extreme-ultra-violet (EUV) source. We present the latest performance results f...
Patent
Full-text available
Ultrafine dimensions are accurately and efficiently formed in a target layer using a spacer lithographic technique comprising forming a first mask pattern, forming a cross-linkable layer over the first mask pattern, forming a cross-linked spacer between the first mask pattern and cross-linkable layer, removing the cross-linkable layer, cross-linked...
Conference Paper
The usable power of high-power EUV light sources at 13.5 nm and also the lifetime of source and collector optics are currently considered to be the largest challenges encountered during the transition of EUV lithography from the current beta-tool status to high-volume manufacturing. Fraunhofer IOF Jena has developed cost-effective refurbishment tec...
Conference Paper
This paper describes the development of a laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source for advanced lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193nm immersion double patterning technology for sub-20nm critical layer patterning. In this paper we discuss the most recent results from h...
Conference Paper
Laser produced plasma (LPP) systems have been developed as the primary approach for use in EUV scanner light sources for optical imaging of circuit features at 20nm nodes and beyond. This paper provides a review of development progress and productization status for LPP extreme-ultra-violet (EUV) sources with performance goals targeted to meet speci...
Article
Extreme ultraviolet (EUV) lithography has emerged as the preferred choice for high-volume manufacturing, now that immersion ArF reaches its limits. Light source power is a key driver to achieve the throughput required for successful adoption of extreme ultraviolet lithography (EUVL). Cymer has developed a laser-produced plasma source based on a hig...
Article
Laser-produced plasma (LPP) sources have been developed as the primary approach for EUV lithography for optical imaging of circuit features at sub-22nm design rules. The three major subsystems of the source are the drive laser, the beam transport system (BTS) and the source vessel. The drive laser is a CO 2 laser with multiple stages of amplificati...
Article
Laser-produced plasma sources offer the best option for scalability to support high-throughput lithography. Challenges associated with the complexity of such a source are being addressed in a pilot program where sources have been built and integrated with extreme-ultraviolet (EUV) scanners. Up to now, five pilot sources have been installed at R&D f...
Article
Through a number of experimental studies carried out on various experimental test stands we are characterizing the scaling of EUV power and collector lifetime. The current performance of the first generation of EUV sources to support EUV lithography scanners is at 20 W power and 70% availability. CO2 drive laser power of up to 17 kW has been reache...
Article
The usable power and the collector optics lifetime of high-power extreme ultraviolet light sources at 13.5 nm are considered as the major challenges in the transitioning of EUV lithography from the current pre-production phase to high volume manufacturing. We give a detailed performance summary of the large ellipsoidal multilayer collector mirrors...
Conference Paper
Laser produced plasma (LPP) systems have been developed as the primary approach for the EUV scanner light source for optical imaging of circuit features at sub-22nm and beyond nodes on the ITRS roadmap. This paper provides a review of development progress and productization status for LPP extreme-ultra-violet (EUV) sources with performance goals ta...
Article
Some of the results of the program that led to the initial measurement of X-ray laser (XRL) gain in Canada were reviewed. A study of the dependence of XRL gain on the shape and duration of the driver laser pulse was presented, providing guidance in ways to enhance the efficiency of XRLs. The study also showed that the pulse rise time was not signif...
Article
Full-text available
We have realized the first demonstration of a table-top aerial imaging microscope capable of characterizing pattern and defect printability in extreme ultraviolet lithography masks. The microscope combines the output of a 13.2 nm wavelength, table-top, plasma-based, EUV laser with zone plate optics to mimic the imaging conditions of an EUV lithogra...
Article
We report the first at-wavelength line edge roughness measurements of patterned EUV lithography masks realized using a table-top aerial imaging system based on a table-top λ=13.2 laser.
Article
In this study, multilayer morphology near the key anomalies in grating-like structures, namely sharp step-edges and steep walls, are examined. Different deposition schemes are employed. Based on cross section TEM analysis an explanatory model describing the morphology of the successive layers is developed. A further insight into the periodicity and...
Article
Reported is a summary of multilayer deposition results by FOM on three elements of the projection optics of the ASML Extreme UV Lithography HVM tools. The coating process used is e-beam evaporation in combination with low-energy ion-beam smoothening. The reflectance of the coatings, which are covered with a special protective capping layer, is typi...
Article
We are evaluating the readiness of extreme ultraviolet (EUV) lithography for insertion into production at the 15 nm technology node by integrating it into standard semiconductor process flows because we believe that device integration exercises provide the truest test of technology readiness and, at the same time, highlight the remaining critical i...
Article
A host of complementary imaging techniques (Scanning Electron Microscopy), surface analytical technique (Auger Electron Spectroscopy, AES), chemical analytical and speciation techniques (Grazing Incidence Reflectance Fourier-Transform Infrared Spectroscopy, GIR-FTIR; and Raman spectroscopy) have been assessed for their sensitivity and effectiveness...
Article
We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMATECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collect...
Article
This paper describes the development of laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source architecture for advanced lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193 nm immersion technology for sub-22 nm critical layer patterning. In this paper we discuss the most recent results from high q...
Article
Microfield exposure tools (METs) play a crucial role in the development of extreme ultraviolet (EUV) resists and masks. One of these tools is the SEMATECH Berkeley 0.3 numerical aperture (NA) MET. Using conventional illumination this tool is limited to approximately 22-nm half pitch resolution. However, resolution enhancement techniques have been u...
Article
Molecular contamination risk to an EUV reticle exposed to up to 1600J/cm2 of 13.5 nm EUV radiation in ASML Alpha Demo Tool (ADT) is negligible. Carbon film (< 0.5 nm) deposition and oxidation (surface oxides ~1 nm) are the two main molecular contaminants observed on this EUV reticle. These results run counter to recent empirical results obtained fr...
Article
Full-text available
This paper assesses the readiness of EUV masks for pilot line production. The printability of well characterized reticle defects, with particular emphasis on those reticle defects that cause electrical errors on wafer test chips, is investigated. The reticles are equipped with test marks that are inspected in a die-to-die mode (using DUV inspection...
Article
We present the latest results on high-power extreme-ultraviolet (EUV) light sources for lithography. This includes operation of high-power pulsed CO2 lasers, high repetition-rate Sn droplet targets, and collection of EUV light using multilayer-coated optics.
Article
Microfield exposure tools (METs) have and continue to play a dominant role in the development of extreme ultraviolet resists and masks. One of these tools is the SEMATECH Berkeley 0.3 numerical aperture (NA) MET. Here, the authors investigate the possibilities and limitations of using the 0.3 NA MET for sub-22-nm half-pitch development. They consid...
Article
Microfield exposure tools continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. Here we present an update on the SEMATECH Berkeley 0.3-NA microfield exposure tool and summarize the latest test results from high-resolution line-space printing. Printing down to 20-nm is presented with large process latitude at 22-n...
Article
We reported that we were successful in our 45nm technology node device demonstration in February 2008 and 22nm node technology node device patterning in February 2009 using ASML's Alpha Demo Tool (ADT).1, 2, 3 In order to insert extreme ultraviolet (EUV) lithography at the 15nm technology node and beyond, we have thoroughly characterized one EUV ma...
Article
Full-text available
The EUV exposure tool settings and OPC strategies to be used for the 16 nm logic node are discussed. Imaging simulation was done for various types of CD through pitch patterns to investigate the tradeoff between NA, illumination settings, and resist diffusion blur. EUV optics still provides very good optical resolution at 56 nm min pitch, but resis...
Article
Full-text available
EUV lithography is one of the most promising methods for next-generation lithography below 22 nm half pitch. However, critical issues such as availability of a clean powerful source, resist resolution and sensitivity, and defect-free masks have yet to be overcome. Flare is one of the key issues for EUV lithography critical dimension (CD) control.1...
Article
Full-text available
Laser produced plasma (LLP) sources are generally considered attractive for high power EUV production in next generation lithography equipment. Such plasmas are most efficiently excited by the relatively long, infrared wavelengths of CO2-lasers, but a significant part of the rotational-vibrational excitation lines of the CO2 radiation will be backs...
Article
Full-text available
Reticle defectivity was evaluated using two known approaches: direct reticle inspection and the inspection of the wafer prints. The primary test vehicle was a reticle with a design consisting of 45 nm and 60 nm comb and serpentine structures in different orientations. The reticle was inspected in reflected light on the KLA 587 in a die-todie and a...
Article
Full-text available
On the road to insertion of extreme ultraviolet (EUV) lithography into production at the 16 nm technology node and below, we are testing its integration into standard semiconductor process flows for 22 nm node devices. In this paper, we describe the patterning of two levels of a 22 nm node test chip using single-exposure EUV lithography; the other...
Article
Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the SEMATECH Berkeley 0.3-NA MET operating as a SEMATECH resist and mask test center. Here we present an update summarizing the latest resist test and characterization results. The relatively small numeric...
Article
The performance of a 0.25NA full-field EUV exposure tool is characterized in terms of CD uniformity, focus and overlay control, as well as dose uniformity. In addition to the characterization of the scanner, we explore the use of scatterometry techniques for the measurements of extremely fine resolution features, with critical dimensions below 40 n...
Article
Full-text available
We present a computational and experimental study on interface passivation of B4C/La multilayers for photolithography at wavelengths beyond 13.5 nm. We successfully applied N-plasma treatment to form interface-localized BN and LaN layers, preventing LaB6 and LaC2 interlayer formation and increasing the optical contrast. Experiments suggest an impro...
Article
Full-text available
Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the 0.3 numerical aperture SEMATECH Berkeley MET operating as a resist and mask test center. Here they present an update on the tool summarizing some of the latest test and characterization results. they p...
Article
Full-text available
In this article the authors discuss the impact of coherence, or laser speckle, of current generation 193 nm argon fluoride (ArF) excimer sources on lithographic patterning. They report a new metrology capability to characterize single-pulse speckle patterns at the exit of the laser aperture and quantify the speckle dependence on time integral squar...
Article
Full-text available
We have used ASML's full field step-and-scan exposure tool for extreme ultraviolet lithography (EUVL), known as an Alpha Demo Tool, to investigate one of the critical issues identified for EUVL, defectivity associated with EUV masks. The main objective for this work was to investigate the infrastructure currently in place to examine defects on a EU...
Presentation
Full-text available
Impacts of laser speckle (spatial / temporal coherence) on lithographic patterning. Presented by Ivan Lalovic at EIPBN Conference 2008 in Portland Oregon
Article
Demanding sub-45 nm node lithographic methodologies such as double patterning (DPT) pose significant challenges for overlay metrology. In this paper, we investigate scatterometry methods as an alternative approach to meet these stringent new metrology requirements. We used a spectroscopic diffraction-based overlay (DBO) measurement technique in whi...
Article
Full-text available
To determine the magnitude of the exposure latitude required for a process to be manufacturable, additional factors are considered that have a similar relationship between linewidth variation and image log-slope. Such parameters include resist thickness, flare, post-exposure bake temperature, and line-edge roughness. To obtain consistency between t...
Article
Full-text available
This paper examines the extendibility of the scatterometry techniques to characterize structures pushing the limits of current lithographic printing technologies. In particular, we investigate the limits of normal-incidence optical CD (NIOCD) measurements using the smallest features afforded by the most recent generation of hyper-NA immersion scann...
Article
Full-text available
In this paper we report the development of nanosecond-pulsed fiber laser technology for the next generation EUV lithography sources. The demonstrated fiber laser system incorporates large core fibers and arbitrary optical waveform generation, which enables achieving optimum intensities and other critical beam characteristics on a laser-plasma targe...
Article
In this paper, we describe the integration of EUV lithography into a standard semiconductor manufacturing flow to produce demonstration devices. 45 nm logic test chips with functional transistors were fabricated using EUV lithography to pattern the first interconnect level (metal 1). This device fabrication exercise required the development of rule...
Article
The authors explore the critical issues remaining for the introduction of extreme ultraviolet lithography (EUVL) in semiconductor manufacturing. Among all technical issues, source power appears to be the most significant challenge that the technology is facing at this time. The lack of sufficiently high-power sources integrated in the first generat...
Conference Paper
Image blur due to chemical amplification represents a fundamental limit to photoresist performance and manifests itself in many aspects of lithographic performance. Substantial progress has been made in linking image blur with simple resolution metrics using EUV lithography. In this presentation, they examine performance of 193 nm resist and EUV re...
Article
Full-text available
Recent upgrades made to the SEMATECH Berkeley microfield exposure tool are summarized and some of the latest resist characterization results are presented. Tool illumination uniformity covering the full 200 600 m 2 wafer-side field of view is demonstrated and intrawafer focus control of 1.8 nm is shown. Printing results demonstrate chemically ampli...
Article
Resist resolution remains a significant issue for EUV. Strong concerns persist regarding the use of chemically amplified resists owing to their diffusion characteristics. Current EUV resist development is focused on a) large-scale screening efforts in an attempt to identify promising platforms and b) refinement and optimization of the processing of...
Article
We describe methods to determine transfer functions for line edge roughness (LER) from the photoresist pattern through the etch process into the underlying substrate. Both image fading techniques and more conventional focus-exposure matrix methods may be employed to determine the dependence of photoresist LER on the image-log-slope (ILS) or resist-...
Article
Operating as a SEMATECH resist test center, the Berkeley 0.3-NA EUV microfield exposure tool continues to play a crucial role in the advancement of EUV resists and masks. Here we present recent resist-characterization results from the tool as well as tool-characterization data. In particular we present lithographic-based aberration measurements dem...
Article
Scatterometry techniques are used to characterize the CD uniformity, focus and dose control, as well as the image contrast of a hyper-NA immersion lithography scanner. Results indicate very good scanner control and stability of these parameters, as well as good precision and sensitivity of the metrology techniques.
Article
In this paper, results and analysis are presented from Advanced Micro Devices' (AMD) efforts at calculating lithography dose and focus parameters using scatterometry metrology and semi-physical CD models. The system takes advantage of the accurate and precise top and bottom CD data produced by scatterometry to differentiate dose and focus variation...
Article
This paper discusses the use of scatterometry for scanner focus control in hyper-NA lithography. A variety of techniques based on phase shift technology have been traditionally used to monitor scanner focus. Recently scatterometry has offered significant promise as an alternate technique to monitor both focus and dose. In this study, we make carefu...
Article
The International Venture for Nanolithography (INVENT) initiative announced in mid 2005, a unique industry-university consortium between the College of Nanoscale Science and Engineering at Albany and a group of leading edge integrated device manufacturers, has launched an extensive R&D program on EUV lithography (EUVL). The overall scope of the INV...
Article
Time-of-flight secondary-ion mass spectrometry (TOF-SIMS) imaging is demonstrated as a sensitive qualitative method for characterizing surface acid concentrations and accompanying chemical changes at resist surfaces. We show its utility in analyzing the 'chemical flare' phenomenon associated with some chemically amplified photoresists. Two commerci...
Article
With decreasing critical dimension (CD) budgets and smaller k1 values the need for perfect focus control becomes paramount. Among the individual contributors to the overall focus budget, the accuracy of the leveling system on a process wafer and the focus setting accuracy for the individual layers are two major contributors. In our study we discuss...
Article
Full-text available
Resist resolution remains a significant issue for EUV. Strong concerns remain with the use of chemically amplified resist owing to their diffusion characteristics. Currently EUV resist development is primarily focused on large-scale screening efforts in an attempt to identify platforms showing promise in a variety of areas with resolution arguably...
Article
Efficient generation of extreme UV (EUV) light at lambda = 13.5 nm from a bulk Sn target has been demonstrated by using a fiber laser. The conversion efficiency from the 1064 nm IR to the EUV was measured to be around 0.9% into 2pi steradians within a 2% bandwidth. To the best of our knowledge, this is the first time an all-fiber system was used to...
Article
Full-text available
Defect-free masks are one of the top issues for enabling EUV lithography at the 32-nm node. Since a defect-free process cannot be expected, an understanding of the defect printability is required in order to derive critical defect sizes for the mask inspection and repair. Simulations of the aerial image are compared to the experimental printing in...
Article
We report on a method to produce any type of phase-shift masks for EUV lithography. We have successfully fabricated an unattenuated phase-shift mask consisting of phase patterns and confirmed the expected performance of such a mask through resist printing at lambda=13.3 nm. Finally actinic metrology reveals that these etched-multilayer masks, left...
Article
Full-text available
The past two years has brought tremendous improvements in the crucial area of resists for extreme ultraviolet (EUV) lithography. Nested and isolated line resolutions approaching 30 nm and 25 nm, respectively, have been demonstrated. These advances have been enabled, in large part, by the high-numerical (0.3) EUV imaging capabilities provided by the...
Article
A method is presented to determine a transfer function for line edge roughness (LER) from the photoresist pattern through the etch process into the underlying material, such as a polysilicon gate. The image fading technique was employed to determine the dependence of photoresist LER on the image-log-slope (ILS) of the aerial image. From this initia...
Article
This paper reports our latest findings on the performance of high and low activation resists for EUV lithography. Both low and high activation resists show good capability down to 35 nm resolution, with acceptable LER and photospeed. These resists also show minimal outgassing of 3.4 x 10(12) molecules/cm(2) outgassed at EUV exposure, well below the...
Article
Full-text available
Several masks have been fabricated and exposed with the small-field Micro Exposure Tool (MET) at the Advanced Light Source (ALS) synchrotron in Berkeley using EUV radiation at 13.5 nm wavelength. Investigated mask types include two different absorber masks with TaN absorber as well as an etched multilayer mask. The resulting printing performance un...
Article
Full-text available
An aberration monitoring technique based on lateral shifts of two-wave interference patterns in centrally obscured optical systems is presented, and simulations are used to evaluate the performance of such a technique. The technique is being explored as a convenient means for monitoring the aberration level in the 0.3-NA Micro Exposure Tool (MET) o...
Article
In this paper we present a method to characterize scattered light in lithography scanners based on the measurement of the modulation transfer function (MTF) of the lens. This method provides a description of scattered light at all length scales, or spatial frequencies, relevant to lithographic printing. We also introduce a new automated technique b...
Article
Full-text available
Three different architectures were compared as candidates for EUV lithography masks. Binary masks were fabricated using two different stacks of absorber materials and using a selective etching process to directly pattern the multilayer of the mask blank. To compare the effects of mask architecture on resist patterning, all three masks were used to...
Article
Photoresist patterning experiments on the EUVL Engineering Test Stand using two masks with different types of architecture indicate that etched-multilayer binary masks can provide larger process latitude than standard patterned absorber masks. The trends observed in the experimental data are confirmed by rigorous electromagnetic simulations taking...
Article
Rigorous electromagnetic scattering simulation is used to characterize mask diffraction for fine structures of various types of EUVL masks. The Cr/SiO2 absorber mask, the etched multilayer mask and the new refilled multilayer mask are studied for lithography performance for line and space features for 32 nm node. The combined process window of 25 n...
Article
Rigorous electromagnetic scattering simulation is used to characterize mask diffraction for fine structures of various types of EUVL masks. The Cr/SiO2 absorber mask, the etched multilayer mask and the new refilled multilayer mask are studied for lithography performance for line and space features for 32 nm node. The combined process window of 25 n...
Article
A technique was developed to investigate the role of aerial image contrast and image-log-slope (ILS) on the resulting magnitude of line edge roughness (LER) in resist with the goal of determining if the minimization of LER in current state-of-the-art, chemically amplified resist materials was limited by the quality of the projected aerial image or...
Article
Photoresist patterning experiments on the EUVL Engineering Test Stand using two masks with different types of architecture indicate that etched-multilayer binary masks can provide larger process latitude than stand