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EXECUTIVE SUMMARY 3 processes, and possibly minimization of problems associated with undesirable emissions such as greenhouse gases and ozone depleters. 2. The major potential benefits of plasma modeling to plasma equipment suppliers include more rapid and efficient development of new tools that meet increasingly stringent process requirements, optimization of designs before fabrication of prototype tools, and development of robust, real-time process control schemes for their tools. 3. The main roadblock to development of plasma models that will have these industrially important uses is the lack of fundamental data on collisional, reactive processes occurring in the plasma and on walls bounding the plasma. Among the most important missing data are the identities of key chemical species and the dominant kinetic pathways that determine the concentrations and reactivities of these key species, especially for the complex gas mixtures commonly used in industry. 4. The lack of a central location to collect, analyze, and disseminate the data that are currently available, or that will be available in the future, is a serious problem. 5. Large numbers of materials and chemistries are used in plasma processes for integrated circuit manufacturing. Given the reality of inevitably limited resources, it is necessary to establish priorities that encourage development of relevant data for only a few of the most important chemistries, both currently and for the next 5 to 10 years. RECOMMENDATIONS 1. Federal funding agencies should make greater and more systematic efforts to support development of an improved database for plasma modeling. In addition, given the direct benefits an improved database would provide for both semiconductor manufacturers and plasma equipment suppliers, organizations set up by industry to promote integrated circuit manufacturing and the semiconductor equipment industry should participate in supporting targeted database development. Greatest emphasis should be placed on surface processes because of their centrality in the technology and because this is the area in which in general the least is known. However, the other database needs outlined in the main text of this reportâelectron-collision processes, spectroscopic/radiative processes, ion-neutral and neutral-neutral chemistry, and thermochemistryâare also important and need considerable work if the models are to achieve their potential impact industrially. Computational approaches to providing database information, using ab initio electronic structure codes as well as semiempirical methods, should be encouraged. 2. A spectrum of plasma models should be developed, aimed at a variety of uses. One set of codes should be developed to provide a compact, relatively fast simulation that addresses plasma and surface kinetics and is useful for process engineers. Convenient user interfaces would be important for this set of codes. A second set of codes would include more sophisticated algorithms and higher dimensionality, and would be more useful for equipment design. Development and testing of models that meet these needs should be supported. Careful validation of the codes by systematic comparison to the results of experiments needs to be undertaken. As learning and resources allow, some development effort should focus on fully three-dimensional plasma, electromagnetic, and neutral transport codes. The degree of chemical complexity to be included will vary depending on the availability of data, the goals of the modeler, and the available computational resources. 3. The following chemistries and materials should have a high priority in database development. The panel chose these systems because the applications are currently important and are anticipated to continue to be important for at least the next 5 years and quite probably beyond that: a. Polycrystalline silicon etching in chlorine-containing gases and bromine-containing gases. This set (of materials and chemistries) is commonly used in the etching step to define the gate electrode in field
