The presentation is devoted to thermodynamic modeling methodology and results obtained in Nikolaev Institute of inorganic Chemistry in application to optimization of CVD processing in technology of electronic materials and structures. Information system containing data bases of thermodynamic parameters used in calculations, models and programs are described. Experimental procedures in development of technology of functional electronic materials are very often time consuming and expensive. Among ways to shorten these procedures thermodynamic modeling requires special attention.
This methodology not only permits to shorten range of tested experimental condition but in many case suggests new solutions. In practice of Institute of Inorganic chemistry, Russian academy of sciences (Novosibirsk, Russia) thermodynamic modeling methodology is used for a long time for different applications in electronic material processing. Some examples will be presented in the talk. Thermodynamic modeling was used for optimization of CVD formation of elementary (Si and Ge) and some binary semiconductors. Most impressive are results of optimization of main process for obtaining polycrystalline silicon – so called Siemens process. Modeling permits to find optimal conditions of different steps of the process: dissolving of metallurgical silicon, deposition of pol-silicon, separation of products of reduction of trichlorosilane, recirculation of different components of the process.
Application of results of the modeling by one of our industrial partners permits to increase significantly production yield of silicon. Similar procedures were applied for optimization of deposition of Ge. GaAs, SiC in CVD processes. Recently in addition to CVD processes with halogenates and hydrates as starting materials MO CVD processes with use of multi-element precursors are used more and more often. In such processes depending on experimental conditions in addition to required phase different other phases can be formed.
Thermodynamic modeling of these types of processes gives a possibility to build so called CVD diagram, where conditions, corresponding to deposition of the required phase or indicated. Such diagrams were built recently for a number of practically important cases Methodology of thermodynamic modeling was also successfully used for considering compatibility of different materials of solid state structure. It was shown that in many cases neighboring materials in devices are not compatible. This can be (and often is) the reason of drift of the device parameters. For some cases recommendations to use intermediate substances helped to improve functionality of the devices.
Thermodynamic modeling of systems of the mentioned types requires a big number of thermodynamic parameters, development of proper models and programs for calculations. This information is collected for systems under consideration in an information system developed and being supported at NIIC SB RAS: Data Bank Property of electronic materials (Db EMP).
Key words: Thermodynamic modeling, CVD processes, multimateials structures, Electronic materials data base.