|
|
Symposium 2001 Abstracts
Applications and Challenges of Process Modeling in Semiconductor IndustryAshok Das Modeling and simulation of semiconductor manufacturing equipment and processes is a multi-disciplinary effort drawing from such diverse fields as fluid dynamics, chemistry, heat and mass transfer, plasma physics, and electromagnetics. Over the past few years, significant strides have been made to address and incorporate several of these phenomena in unified models. These advances have enabled the optimization of many chamber geometries and manufacturing processes through modeling. Several examples are presented to illustrate these modeling applications especially as it relates to chemical engineering. In particular, the role of modeling in the development of Epi, HDP-CVD, PECVD, LPCVD, PVD and Etch chambers will be discussed. Additionally, significant challenges in this area are also presented that must be overcome before comprehensive reactor models may become commonplace. Many of the physical phenomena occurring in processing equipment are not well understood or characterized, neither are most of the chemical reaction mechanisms and pathways of relevance to real processes. Computational models have difficulty handling stiff chemistry equations and the resulting convergence problems. More importantly, there is a lack of fundamental data necessary to accurately simulate the relevant processes. A long-term sustained research effort is required from chip-makers, equipment companies, academia, national laboratories and commercial software developers to overcome these shortcomings. Micro-contamination and Particulate Cleaning Using HFC FormulationsAbid N. Merchant This paper will discuss several new environmentally friendly HFC formulations as replacements for ozone depleting and global warming CFCs. The presentation will include theoretical considerations of particulate removals and fluid dynamics as well as properties of these formulations such as their physical, thermodynamic, heat-transfer and cleaning properties and performance in various cleaning applications. Some case studies will be included where these formulations have successfully replaced global warming PFC solvents and energy intensive aqueous cleaning processes with improved shorter cleaning cycles and reduced capital investment. Exciting Developments in Fluoropolymers and Fluorochemicals for the Semiconductor IndustryKeynote AddressLouis Glasgow DuPont pioneered the commercialization of fluorochemicals and fluoropolymers. Despite their relatively high cost, the unique properties of these materials have made them indispensable in applications across a wide range of industries including aerospace, automotive, telecommunications, and semiconductor manufacturing. This talk will describe some of the development history of these compounds and provide a look at some of our newer products and research directions. We see a very bright future for fluorochemicals and fluoropolymers in semiconductor applications as we, along with the industry, continue to push toward higher levels of performance. Fluorochemicals are used in the semiconductor industry as cleaning solvents, and as dry-etching and chamber cleaning gases. New developments in these areas of application will be reviewed, including our latest offering Zyron¨ 8020, an optimum fluorocarbon gas for in-situ CVD chamber cleaning applications. Vertrel ¨ specialty fluids are newer, ozone-friendly nonflammable replacements for CFC products. These fluids possess highly desirable physical properties such as low surface tension, low viscosity, excellent material compatibility and desired solvancy to be effective in applications such as flushing, degreasing, carrier fluid for lubrication and aerosol applications. Major uses of these products are in computer, electronic, circuit board manufacture and aerospace applications. The semiconductor processing industry spends billions of dollars to build and maintain high purity manufacturing: clean rooms, ultra-pure chemicals, isolating people from processes, etc. Sources of contamination are continuously tracked down and eliminated, to provide the highest chip yield and the highest functional reliability of the chip circuitry. Much of the processing equipment is made from fluoropolymers, which can be a significant source of contamination through the collection of ionic contaminants on polar end groups. DuPont Teflon¨ PFA HP and now Teflon¨ PFA HPplus, with fully fluorinated non-polar end groups set a new standard for purity and reliability, and eliminate contamination carried by polar end-groups. A new fluoropolymer manufacturing facility started up in January based on new process technology for running polymerizations in carbon dioxide solvent (rather than in aqueous emulsions). An early glimpse of the expectations and plans for this new technology will be given. A range of our new product developments will be described including: Teflon¨ AF for optical fiber and components Productivity Solutions for Silicon Etch Processes through Plasma and Surface DiagnosticsErik A. Edelberg, Vahid Vahedi, Linda Braly and John
Daugherty Saurabh Ullal, Anna Godfrey and Eray S. Aydil H.K. Chiu and H.J. Tao Various diagnostics have been developed with the goal of understanding the root causes of and eliminating what leads to within-lot and lot-to-lot feature variability in silicon etch applications. In low pressure plasma processes, wall and surface reactions such as radical recombination and etch product adsorption can play a significant role in determining the plasma properties and therefore the etching behavior of the system. Etch products from the wafer can adsorb and build up on the walls of the chamber leading to changes in the wall properties. These changes can lead to drifts in the plasma properties and thereby cause within-lot variability of the etch process. By understanding the chemistry and composition of the deposited materials on the walls of the chamber and in the gas phase, an appropriate reactor cleaning process can be developed and optimized. A multiple pass downstream FTIR spectrometer is used to quantitatively measure the concentration of gas phase species such as SiCl4 and SiF4. A novel diagnostic based on the principles of attenuated total internal reflection FTIR spectroscopy is used to measure, in-situ, the presence of and composition of material deposited or removed from the walls of the chamber. In particular, during a Si etch process, the deposited films are found to be by-products of the gas phase species and contain Si, O and Cl. We show that performing a short plasma chamber clean with appropriate chemistry between each wafer can reduce the within-lot feature variability as well as eliminate chamber buildup effects. In Need of Engineering Talent ö Semiconductor Equipment Industry Perspective Romek Nowak The expansion and use of semiconductor devices in many areas of our daily lives as well as their impact on improvements of productivity in conducting business and manufacturing of goods have propelled the growth of the semiconductor equipment industry at a rate higher than historically observed in steel, chemical, or even plastics industries. Such a fast expansion of the industry combined with the complexity of the technology and equipment used for semiconductor manufacturing is fueling the need for a highly skilled and technically competent work force in engineering. This presentation will provide an overview of the industry challenges and a perspective on opportunities for chemical engineers willing to dedicate their professional carrier to development of future technologies, products, and equipment for the semiconductor manufacturing. About the Speaker Dr. Romek Nowak is a General Manager of Applied Global University. In his role he manages development of curriculum and training delivery to 20 thousand Applied Materials employees worldwide. Dr. Nowak has 12 years of extensive experience in managing technology development (as head of Core Technologies) and in new product development (as Dielectric CVD general manager). In addition, he is responsible for funding and management of University Programs at Applied Materials. He holds degrees in physics (MS) and physical chemistry (PhD). Novel Materials for the Electronics Industry Henry C. Chang Restrictions on the use of chlorofluorocarbons (CFCs) because of their ozone depleting (ODP) properties and the potential regulatory concerns with high global warming potential (GWP) materials have affected countless industrial applications including many in the semiconductor industry. Elimination of ODP substances via the Montreal Protocol and emission reductions of high GWP, hazardous air pollutants (HAPs), and volatile organic compounds (VOCs) via Clean Air Act and OSHA standards have already taken effect requiring many process and maintenance modifications. In light of these changes, 3M Company's Specialty Materials Division has developed alternative chemistries to meet these new requirements by introducing novel fluorine based gases, solvents, and surface modifiers. These novel chemistries include segregated hydrofluoroethers (HFEs), fluorosurfactants, and highly fluorinated gases which are being used for applications such as plasma etch, solvent etch, heat transfer, refrigeration, cleaning, drying, additives, and coatings. In addition, 3M has developed process optimization techniques such as in-line emissions monitoring via FTIR for plasma etch and in-line moisture monitoring for heat transfer applications. All targeted to eliminate ODP substances and reduce emissions while meeting and/or surpassing their performance requirements. Speaker Bio Henry C. Chang is a Sr. Account Specialist with 3M Specialty Materials Division. He holds a graduate degree from the University of Notre Dame in Chemical Engineering and holds two patents relating to solvent drying applications. He has been working within the semiconductor industry for the past five years ranging from product development to marketing to sales. He is currently based in the San Jose, CA area with responsibilities in the Semiconductor and Data Storage industries for the Western U.S. Environmentally Benign Semiconductor Processing Dr. Kenneth Aitchison The modern semiconductor industry is a multidisciplinary enterprise requiring the talents of people from numerous science and engineering disciplines. In it's most basic form, a semiconductor fab is a unique collection of (mostly) chemically-based unit processes whose measure of output is the wafer, and Cost-of-Ownership per unit process is a key metric. The semiconductor industry has generally enjoyed a favorable reputation for environmental, health and safety performance. The challenge of maintaining industry growth without worsening its EHS impact has been recognized by industry leaders. A number of industry consortia exist with the goal of resolving pervasive technical problems in a pre-competitive environment in a cost-effective manner. This talk will discuss how those consortia are helping to reduce the already low environmental impact of semiconductor manufacturing. This talk will also illustrate specific examples of cost-effective waste minimization and pollution prevention in the areas of Global Warming Gas emission reduction, copper electroplating and abatement technology. Biography Dr. Kenneth Aitchison is Sr. Director, Technology at Novellus Systems Inc., and was most recently Senior Director of Systems Environmental, Safety and Health in which position he held corporate responsibility for life cycle management of chemical processes and products used in semiconductor process equipment. His work resulted in Novellus receiving a prestigious Global Climate Protection Award from The U.S. EPA in 2000, one of only 19 such awards given internationally. He has over 20 years of experience in the field of materials processing chemistry including CVD, sputtering, sol-gel and electrodeposition. He was formerly Manager of the Advanced Materials and Processing Section, The Aerospace Corporation, and prior to that Director of Technology, Genus, Inc. Materials Sciences Division. He holds a B.A. in Chemistry from New York University and a Ph.D. in Chemistry from Queen Mary College, The University of London. He is the Co-Chair for Industrial-Academic Affairs of the Industrial Advisory Board of the NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing. He is also a member of the Intergovernmental Panel on Climate Change Expert Group for Semiconductor Manufacturing. He is a Research Affiliate of the Microsystems Technology Laboratory at MIT. He is a member of the American Chemical Society, the American Vacuum Society and the American Association for Crystal Growth. Dr Aitchison is the author of over 20 publications and 1 patent.
|