Papers

AVS2001 Session VST+MS-FrM: Semiconductor & Functional Coating Systems & Processes

Friday, November 2, 2001 8:20 AM in Room 125

Friday Morning

Start	Invited?	Item
8:20 AM		VST+MS-FrM-1 Advances in Semiconductor Physical Vapor Deposition Equipment; Vacuum, System Architecture, and PVD Source Technology D.J. Harra (Novellus Systems, Inc.) Recent advances in physical vapor deposition (PVD) equipment have enabled 0.13-micron and smaller semiconductor device geometries, while also supporting technology transitions from traditional aluminum interconnects to copper, as well as wafer size transitions from 200 mm to 300 mm. Evolutions in PVD system architecture and wafer flow that enable high productivity, as well as incorporation of new technologies such as ionized PVD, and CVD are discussed. In addition, recent developments in sputter source technology will also be discussed. Selected process applications and results are presented to illustrate PVD extendibility to future technology nodes.
9:00 AM		VST+MS-FrM-3 Enhancement of Dielectric CVD Remote Clean Competitiveness Through Improved Gas Utilization T. Nowak, T. Tanaka, B.H. Kim, M. Seamons, K.B. Jung (Applied Materials, Inc.) Remote plasma cleaning of dielectric CVD process chambers has been shown to virtually eliminate emission of global warming gases, increase chamber throughput, and increase the lifetime of process chamber hardware. Nitrogen trifluoride (NF₃) is the principal precursor used in remote plasma cleaning applications because of the ease with which it is dissociated and the high atomic fluorine content achievable at the exit of the remote plasma source. The relatively high cost of NF₃, however, makes improvement of gas utilization during the remote clean and development of alternative chemistries critical to enhancing the competitiveness of this green manufacturing process. Building on earlier experimental work, we have developed process models and designed experiments to investigate fluorine radical loss mechanisms and utilization efficiencies within parallel plate plasma CVD reactors. Modeling was based on an iterative solution of a one-dimensional flow network with variable gas composition to model transport and recombination losses from the remote plasma source to the process chamber. Calculated values of the atomic fluorine concentration in the process chamber were verified experimentally by measuring etch rates on SiO₂ wafers. Using the results of the simulation we were able to develop more efficient remote clean processes that, depending on residue to be cleaned, reduce NF₃ consumption by up to 60% without impacting chamber throughput. In addition, we investigated C₃F₈ as an alternative feed gas for the remote clean. Experiments showed that cleaning rates on the order of 80% of NF₃-based cleans were achievable using C₃F₈.
9:20 AM		VST+MS-FrM-4 Vacuum System Architecture for Disk and Flat Panel Production Tools J.L. Hughes, J. Busch (Intevac Inc.) Production tools using high vacuum environments are increasingly used by industry, with their requirements growing more difficult. Two such applications are flat panel displays and magnetic hard disks. The flat panel uses up to 1.2 x 1.6 meter rectangular substrates of 1.1 mm thick glass, while hard disks are typically 95 mm circular aluminum. The methods for thin film deposition by sputtering for the two systems varies greatly for the two applications. The same thing is true for substrate transport. But some methods and principals remain the same in either type of production. Vacuum levels run from 1.0E-08 Torr for high vacuum to sputtering pressures of 5.0E-03 Torr. This article looks at two specific examples of vacuum system architecture and draws out the specifics of difference and samenesss between the two.
10:00 AM		VST+MS-FrM-6 Disassembling and Materials Recovering Process of Zinc-Carbon battery by Vacuum Aided Recycling Systems Technology Y. Saotome (Gunma University, Japan); Y. Nakazawa (Kokushikan University, Japan); Y. Yamada (Nagata Seiki Co., Ltd., Japan) Every material has its own vapor pressure and the principle of VARS Tech. is based on sorting and recovering a specific material from the midst of other combined products through evaporation in a vacuum and the use of different evaporation temperatures for each material.¹ In the present paper, VARS Tech. has been applied to the recycling of used batteries. Zinc-Carbon battery R20PU was selected as a specimen and was heated by radiation through vacuum vessel wall made of glass. The resulting relationship between vacuum pressure, reduction in mass and the temperature during heating indicates the occurrence of some evaporation. For the analyses of these complex phenomena, similar experiments were carried out on each component and material of the battery. As a result, at the temperature of about 450K, PVC insulation ring at the top of the battery becomes warped and then water(solution) is evaporated from the inside of battery. From the aspect of recycling process, softening and decomposition phenomenon of PVC insulation ring is correspond to the beginning of disassembling of battery as an assembled product. Actually, disassembling process is accelerated by the evaporation of ZnCl₂ and can-zinc above about 700K. After the vacuum thermal cycle, the specimen is disassembled and comes to parts such as jacket-metal, some plate metals, an electrode-carbon and positive reactant in powder state. As shown above, the vacuum-aided recycling method is a process that consists of disassembling, sorting, and recovering materials. As shown above, vacuum aided recycling technology has superior characteristics as a restoration systems technology of EcoFactory. As shown above, vacuum aided recycling technology has superior characteristics as a restoration systems technology of EcoFactory. ¹ Y.Saotome, Y.Nakazawa and Y.Yamada, Vacuum, 53(1999), 101-104.
10:40 AM		VST+MS-FrM-8 The Foundations of Vacuum Coating Technologies D.M. Mattox (Management Plus, Inc.) Vacuum coatings processes use a vacuum environment and an atomic or molecular vapor source to deposit thin films and coatings. The vacuum environment is used not only to reduce gas particle density but also to limit gaseous contamination, establish partial pressures of gases and control gas flow. Electric power is used to thermally vaporize material, thermally decompose vapors, activate reactive species, generate plasmas and accelerate ions. This paper will trace the development of vacuum technology from the piston water pumps of the Roman Empire, the development of electric power from frictional electricity machines and the electrolytic cell, and the development of deposition techniques based on thermal evaporation, sputtering, arc vaporization, laser ablation and chemical vapor precursors. Both patent and technical literature will be cited as to the first reports on phenomena and processes and the beginnings of sustained applications of various vacuum-coating processes. Several areas of uncertainty will be described and discussed. Often these uncertainties are due to problems with terminology or to the differing nature of patent and technical literature. Several areas where original ("pioneering") work is commonly attributed to an inappropriate individual(s) will be discussed.
11:00 AM		VST+MS-FrM-9 Downstream Effluent Management Subsystems for Semiconductor Manufacturing Processes Y. Gu (MKS Instruments, Inc.) Smaller geometry and larger wafer size are the major trends for today's semiconductor device manufacturing industry in order to attain higher throughput and better device performance. At the same time, tool uptime and process yield become more important as they are closely related to the fab throughput. Significant efforts have been spent on improving the process throughput by employing advanced tools, new process chemistries and more efficient in-situ cleaning steps. However, it was found that the tool usage is often reduced because of existing downstream problems. In addition, particle levels on wafer surface are also related to the cleanness of the pump line. These problems are even getting worse because of the use of more reactive precursors, which are intended to reduce the process temperature and increase the deposition rate. The most common processes which are experiencing significant downstream problems are silicon nitride LPCVD, TEOS LPCVD, Aluminum etch, tungsten CVD process, silicon Epi, and variety of other processes. These problems can be caused by physical sublimation of the condensable by-products, or the complex chemical reactions between unreacted precursors, by-products, and/or the vapor backstreaming from the scrubber. Different techniques are required to manage these effluent problems because of their different mechanism. In addition, a systematic solution is often required in order to prevent creating a problem. Several downstream effluent management subsystems developed at MKS Instruments Inc. will be discussed in this talk. They have been proven very effective to improve semiconductor manufacturing process uptime and yield.