Mathematical Modeling Of Chemical Vapor Deposition Processes And Its Application To Thin Film Technology

A number of workers in the field of Chemical vapor deposition (CVD) have presented mathematical models in the literature. Some workers were able to produce analytical expressions for the interwafer concentration profile. These analytical expressions were based entirely on zero or first order chemical reaction rates. Until now, it appears that a chemical reaction rate expression that is not zero or first order directly, must be handled by a numerical scheme. Presented herein is a mathematical model with an analytical interwafer concentration profile. This concentration profile is neither zero nor first order but shifts from zero to first order as the reactor is axially traversed. The approach used avoids the sometimes cumbersome numerical schemes, while dealing effectively with non-integer order rate expressions characteristic to CVD kinetics. This approach is also amenable to higher order rate expressions such as kCn, n> 1. We employ a boundary perturbation technique to reduce a nonlinear system of partial differential equations that was otherwise non-tractable analytically. Essentially, analytical expressions are derivable for the concentration profile in the interwafer region regardless of the kinetic expression's non-linearity. The proposed model was tested with independently published experimental data. In each case the model predictions compare favorable with the experimental data. Results show that deposition rates of: silicon nitride from dichlorosilane and ammonia, silicon from silane and silicon dioxide from tetraethylorthosilicate can be explained using a shifting order reaction. Further, the neglect of gas phase reactions did not affect the predicted deposition rates. Concurrence with experimental results on thickness uniformity (radial) is achieved using this model. Control of nonuniformity on the wafers during a CVD process depends on the magnitude of the Sherwood number. Both experimental data and the proposed model show that surface uniformity improves with diminishing Sherwood numbers. In this work, it is demonstrated (at least qualitatively) that surface chemical reaction provides the controlling resistance. For the range of concentrations and low pressures used in CVD the interwafer Damkzh̲ler number is smaller than unity. If the ratio of reaction velocity to diffusion velocity is larger than unity, uniform surface deposition cannot be expected. This implies the surface process is controlling.

The focus of this book is on modeling and simulations used in research on the morphological evolution during film growth. The authors emphasize the detailed mathematical formulation of the problem. The book will enable readers themselves to set up a computational program to investigate specific topics of interest in thin film deposition. It will benefit those working in any discipline that requires an understanding of thin film growth processes.

Semiconductor equipment modeling has in recent years become a field of great interest, because it offers the potential to support development and optimization of manufacturing equipment and hence reduce the cost and improve the quality of the reactors. This book is the result of two parallel lines of research dealing with the same subject - Modeling of Tungsten CVD processes -, which were per formed independently under very different boundary conditions. On the one side, Chris Kleijn, working in an academic research environment, was able to go deep enough into the subject to laya solid foundation and prove the validity of all the assumptions made in his work. On the other side, Christoph Werner, working in the context of an industrial research lab, was able to closely interact with manufacturing and development engineers in a modern submicron semiconductor processing line. Because of these different approaches, the informal collaboration during the course of the projects proved to be extremely helpful to both sides, even though - or perhaps because - different computer codes, different CVD reactors and also slightly different models were used. In spite of the inconsistencies which might arise from this double approach, we feel that the presentation of both sets of results in one book will be very useful for people working in similar projects.

This work describes the development of a mathematical model of ahigh-pressure chemical vapor deposition (HPCVD) reactor and nonlinearfeedback methodologies for control of the growth of thin films in thisreactor. Precise control of the film thickness and composition is highlydesirable, making real-time control of the deposition process veryimportant. The source vapor species transport is modeled by the standardgas dynamics partial differential equations, with species decomposition reactions, reduced down to a small number of ordinary differential equationsthrough use of the proper orthogonal decomposition technique. This systemis coupled with a reduced order model of the reactions on the surfaceinvolved in the source vapor decomposition and film deposition on thesubstrate wafer. Also modeled is the real-time observation technique usedto obtain a partial measurement of the deposition process. The utilization of reduced order models greatly simplifies the mathematical formulation of the physical process so it can be solved quickly enough to beused for real-time model-based feedback control. This control problem isfairly complicated, however, because the surface reactions render the modelnonlinear. Several control methodologies for nonlinear systems are studiedin this work to determine which performs best on test examples similar tothe HPCVD problem. One chosen method is extended to a tracking control toforce certain film growth properties to follow desired trajectories. Thenonlinear control method is used also in the development of a stateestimator which uses the nonlinear partial observation of the nonlinearsystem to create an estimate of the actual state, which the feedback controlformula then can use to guide the HPCVD system. The nonlinear trackingcontrol and estimator techniques are implemented on the HPCVD model and theresults analyzed as to the effectiveness of the reduced order model andnonlinear control.

Presents an extensive, comprehensive study of chemical vapor deposition (CVD). Understanding CVD requires knowledge of fluid mechanics, plasma physics, chemical thermodynamics, and kinetics as well as homogenous and heterogeneous chemical reactions. This text presents these aspects of CVD in an integrated fashion, and also reviews films for use in integrated circuit technology.

Handbook of Chemical Vapor Deposition: Principles, Technology and Applications provides information pertinent to the fundamental aspects of chemical vapor deposition. This book discusses the applications of chemical vapor deposition, which is a relatively flexible technology that can accommodate many variations. Organized into 12 chapters, this book begins with an overview of the theoretical examination of the chemical vapor deposition process. This text then describes the major chemical reactions and reviews the chemical vapor deposition systems and equipment used in research and production. Other chapters consider the materials deposited by chemical vapor deposition. This book discusses as well the potential applications of chemical vapor deposition in semiconductors and electronics. The final chapter deals with ion implantation as a major process in the fabrication of semiconductors. This book is a valuable resource for scientists, engineers, and students. Production and marketing managers and suppliers of equipment, materials, and services will also find this book useful.

This monograph is a summary of equipment, methodology and thin film growth experience obtained by the author during his 30 years of research work in the field of Integrated Circuit (IC) device technology. The monograph is concerned with the analysis of different aspects of different types of inorganic thin films grown by Chemical Vapor Deposition (CVD) methods and dedicated to the use in IC technology and production. The author discusses the methodology issues of thin film CVD and the fundamentals of the chemical kinetics of thin film growth. The main core of this monograph is the analysis of thin film CVD kinetics features obtained using different types of reactors, chemical compounds, process conditions. The monograph covers a wide variety of CVD-related aspects: equipment analysis, chemical compound features, CVD process methodology analysis, CVD kinetic features and their quantitative characterization, implementation of obtained numerical equations for thin film step coverage and gap-fill issues, interrelation of the film properties and CVD process features, and CVD process classification. The author would like to highlight that all the data presented in this book has been experimentally obtained by a number of research groups. Most of the data has been double-checked and confirmed. Surely, some data could not be repeated because it was obtained a long time ago using some specific deposition tools and processes. Nevertheless, the author would like to stress that he considers this book as an attempt to create a whole view on the thin film CVD for IC device technology applications. In this regard, the author has tried to generalize a large amount of experimental data, selecting the most common features of the film growth, composition, structure, and properties.

The authoritative reference on catalytic chemical vapor deposition, written by the inventor of the technology. This comprehensive book covers a wide scope of Cat-CVD and related technologies from the fundamentals to the many applications, including the design of a Cat-CVD apparatus. Featuring contributions from four senior leaders in the field, including the father of catalytic chemical vapor deposition, it also introduces some of the techniques used in the observation of Cat-CVD related phenomena so that readers can understand the concepts of such techniques. Catalytic Chemical Vapor Deposition: Technology and Applications of Cat-CVD begins by reviewing the analytical tools for elucidating the chemical reactions in Cat-CVD, such as laser-induced fluorescence and deep ultra-violet absorption, and explains in detail the underlying physics and chemistry of the Cat-CVD technology. Subsequently it provides an overview of the synthesis and properties of Cat-CVD-prepared inorganic and organic thin films. The last parts of this unique book are devoted to the design and operation of Cat-CVD apparatuses and the applications. Provides coherent coverage of the fundamentals and applications of catalytic chemical vapor deposition (Cat-CVD) Assembles in one place the state of the art of this rapidly growing field, allowing new researchers to get an overview that is difficult to obtain solely from journal articles Presents comparisons of different Cat-CVD methods which are usually not found in research papers Bridges academic and industrial research, showing how CVD can be scaled up from the lab to large-scale industrial utilization in the high-tech industry. Catalytic Chemical Vapor Deposition: Technology and Applications is an excellent one-stop resource for researchers and engineers working on or entering the field of Cat-CVD, Hot-Wire CVD, iCVD, and related technologies.

The most recent developments and techniques in thin film deposition for high technology applications are described by 23 authorities in the field.