Author: Marquis Grant Crose
Publisher:
ISBN:
Category :
Languages : en
Pages : 195
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Book Description
Today, plasma-enhanced chemical vapor deposition (PECVD) remains the dominant processing method for the manufacture of silicon thin films due to inexpensive production and low operating temperatures. Nonetheless, thickness non-uniformity continues to prevent the deposition of high quality thin film layers across large wafer substrates; thickness deviations up to 20% are typical for 200 mm and above wafers. Regardless of industry, be it solar cell production or microelectronic devices, the demand for densely packed die with high quality creates a need for improved modeling and operational strategies. Over the past two decades, a number of research groups have built microscopic models for thin film growth, as well as macroscopic reactor models to approximate the gas phase reaction and transport phenomena present within PECVD systems. Unfortunately, many of the proposed modeling and simulation techniques have been overly simplified in order to reduce computational demands, or fail to capture both the macro- and microscopic domains simultaneously. In order to address persistent issues related to thickness non-uniformity in silicon processing, advanced multiscale models are needed. Motivated by these considerations, novel reactor modeling and operational control strategies are developed in this dissertation. Specifically, a macroscopic reactor scale model is presented which captures the creation of a radio frequency (RF) plasma, transport throughout the reactor domain, and thirty-four dominant plasma-phase reactions. In Chapters 2 and 3, the gas-phase dynamics are approximated using a first principles-based model, whereas the latter half of this dissertation relies on a computational fluid dynamics approach. At the microscopic scale, the complex particle interactions that define the growth of a-Si:H thin film layers are tracked using a hybrid kinetic Monte Carlo algorithm. These scales are linked via a dynamic boundary condition which is updated at the completion of each time step. A computationally efficient parallel programming scheme allows for significantly shortened computational times and solutions to previously infeasible system sizes. Transient batch deposition cycles using the aforementioned multiscale model provide new insight into the operation of PECVD systems; spatial non-uniformity in the concentration of SiH3 and H above the substrate surface is recognized as the primary mechanism responsible for non-uniform thin film product thicknesses. Two key modes are identified to address the aforementioned non-uniformity: (1) run-to-run control of the wafer substrate temperature through the adaptation of an exponentially-weighted moving average algorithm, and (2) the design of new CVD geometries which minimize spatial variations in the concentration of deposition species. These efforts have resulted in optimized PECVD showerhead designs and spatial temperature profiles which limit the thin film thickness non-uniformity to within 1% of the product specification.
Author: Yichi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 151
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Book Description
Facilitated by the increasing importance and demand of semiconductors for the smartphoneand even the automobile industry, thermal atomic layer deposition (ALD) has gained tremendous industrial interest as it offers a way to efficiently deposit thin-films with ultra-high conformity. It is chosen largely due to its superior ability to deliver ultra-conformal dielectric thin-films with high aspect-ratio surface structures, which are encountered more and more often in the novel design of metal-oxide-semiconductor field-effect transistors (MOSFETs) in the NAND (Not-And)-type flash memory devices. Based on the traditional thermal ALD method, the plasma enhanced atomic layer deposition (PEALD) allows for lower operating temperature and speeds up the deposition process with the involvement of plasma species. Despite the popularity of these two methods, the development of their operation policies remains a complicated and expensive task, which motivates the construction of an accurate and comprehensive simulation model. A series of studies have been carried out to elucidate the mechanisms and the conceptof the PEALD process. In particular, process characterization focuses on the development of a first-principles-based three-dimensional, multiscale computational fluid dynamics (CFD) model, together with reactor geometry optimizations, of SiO2 thinfilm thermal atomic layer deposition (ALD) using bis(tertiary-butylamino)silane (BTBAS) and ozone as precursors. Also, a comprehensive multiscale computational fluid dynamics (CFD) model incorporating the plasma generation chamber is used in the deposition of HfO2 thin-films utilizing tetrakis(dimethylamido) hafnium (TDMAHf) and O2 plasma as precursors. Despite the great deal of research effort, ALD and PEALD processes have not been fullycharacterized from the view point of process control. This study aims to use previously developed multiscale CFD simulation model to design and evaluate an optimized control scheme to deal with industrially-relevant disturbances. Specifically, an integrated control scheme using a proportional-integral (PI) controller and a run-to-run (R2R) controller is proposed and evaluated to ensure the deposition of high-quality conformal thin-films. The ALD and PEALD processes under typical disturbances are simulated using the multiscale CFD model, and the integrated controllers are applied in the process domain. Using the controller parameters determined from the open-loop results, the developed integrated PI-R2R controller successfully mitigates the disturbances in the reactor with the combined effort of both controllers.
Author: Rupak Biswas
Publisher: DEStech Publications, Inc
ISBN: 160595022X
Category : Computers
Languages : en
Pages : 703
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Book Description
Author: Damien Tromeur-Dervout
Publisher: Springer Science & Business Media
ISBN: 3642144381
Category : Science
Languages : en
Pages : 428
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Book Description
This book collects the proceedings of the Parallel Computational Fluid Dynamics 2008 conference held in Lyon, France. Contributed papers by over 40 researchers representing the state of the art in parallel CFD and architecture from Asia, Europe, and North America examine major developments in (1) block-structured grid and boundary methods to simulate flows over moving bodies, (2) specific methods for optimization in Aerodynamics Design, (3) innovative parallel algorithms and numerical solvers, such as scalable algebraic multilevel preconditioners and the acceleration of iterative solutions, (4) software frameworks and component architectures for parallelism, (5) large scale computing and parallel efficiencies in the industrial context, (6) lattice Boltzmann and SPH methods, and (7) applications in the environment, biofluids, and nuclear engineering.
Author: Jang-Hyuk Kwon
Publisher: Elsevier
ISBN: 0080550045
Category : Computers
Languages : en
Pages : 320
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Book Description
The proceedings from Parallel CFD 2006 covers all aspects of parallel computings and its applications. Although CFD is one of basic tools for design procedures to produce machineries, such as automobiles, ships, aircrafts, etc., large scale parallel computing has been realized very recently, especially for the manufactures. Various applications in many areas could be experienced including acoustics, weather prediction and ocean modeling, flow control, turbine flow, fluid-structure interaction, optimization, heat transfer, hydrodynamics.- Report on current research in the field in an area which is rapidly changing - Subject is important to all interested in solving large fluid dynamics problems - Interdisciplinary activity. Contributions include scientists with a variety of backgrounds
Author: F. Pappetti
Publisher: Nova Publishers
ISBN: 9781560723547
Category : Science
Languages : en
Pages : 264
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Book Description
Introduction to Parallel Computational Fluid Dynamics
Author: Ismail H. Tuncer
Publisher: Springer Science & Business Media
ISBN: 3540927441
Category : Mathematics
Languages : en
Pages : 489
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Book Description
At the 19th Annual Conference on Parallel Computational Fluid Dynamics held in Antalya, Turkey, in May 2007, the most recent developments and implementations of large-scale and grid computing were presented. This book, comprised of the invited and selected papers of this conference, details those advances, which are of particular interest to CFD and CFD-related communities. It also offers the results related to applications of various scientific and engineering problems involving flows and flow-related topics. Intended for CFD researchers and graduate students, this book is a state-of-the-art presentation of the relevant methodology and implementation techniques of large-scale computing.
Author: A. Deane
Publisher: Elsevier
ISBN: 0080467938
Category : Computers
Languages : en
Pages : 539
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Book Description
The proceedings from Parallel CFD 2005 covering all aspects of the theory and applications of parallel computational fluid dynamics from the traditional to the more contemporary issues.- Report on current research in the field in an area which is rapidly changing- Subject is important to all interested in solving large fluid dynamics problems- Interdisciplinary activity. Contributions include scientists with a variety of backgrounds
Author: Chiao-ling Lin
Publisher: Elsevier
ISBN: 0080538398
Category : Mathematics
Languages : en
Pages : 549
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Book Description
This book contains the papers presented at the Parallel Computational Fluid Dynamics 1998 Conference. The book is focused on new developments and applications of parallel technology. Key topics are introduced through contributed papers and invited lectures. These include typical algorithmic developments, such as: distributed computing, domain decomposition and parallel algorithm. Some of the papers address the evaluations of software and machine performance and software tool environments. The application of parallel computers to complex fluid dynamics problems are also conveyed through sessions such as DNS/LES, combustion and reacting flows, industrial applications, water resources and environmental flows.The editors believe this book will provide many researchers, much beyond those contributing to this volume, with fresh information and reference.
Author: Gabriel Winter
Publisher: Elsevier
ISBN: 0080460968
Category : Computers
Languages : en
Pages : 415
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Book Description
Parallel CFD 2004, the sixteenth international conference on Parallel Computational Fluid Dynamics and other modern scientific domains, has been held since May 24th till May 27th, 2004 in Las Palmas de Gran Canaria, Spain. The specialized, high-level Parallel CFD conferences are organised on travelling locations all over the world, yearly because of multidisciplinary subject of parallel CFD and its rapidly evolving nature.The conference featured 8 invited lectures, 3 Mini Symposia, contributed papers and one Tutorial & Short Course. More than 80 multi-disciplinary presentations of the Parallel CFD had been presented, with participants from 17 countries. The sessions involved contributed papers on many diverse subjects including turbulence, complex flows, unstructured and adaptive grids, industrial applications, developments in software tools and environments as parallel optimization tools. This Book presents an up-to-date overview of the state of the art in parallel computational fluid dynamics.- Report on current research in the field.- Researchers around the world are included.- Subject is important to all interested in solving large fluid dynamics problems.- It is of interest to researchers in computer science, engineering and physical sciences.- It is an interdisciplinary activity. Contributions include scientists with a variety of backgrounds.- It is an area which is rapidly changing.
