NUMERICAL MODELING TOOLS FOR CHEMICAL VAPOR DEPOSITION

THE MICROGRAVITY ENVIRONMENT OF EARTH ORBIT HAS THE POTENTIAL TO IMPROVE THE QUALITY AND INCREASE THE YIELD OF MATERIALS GROWN BY CHEMICAL VAPOR DEPOSITION (CVD). THE DEVELOPMENT OF CVD IN SPACE WOULD BENEFIT GREATLY FROM THE CAPABILITY TO PREDICT THE IMPORTANT PROCESS HEHAVIOR, ESPECIALLY UNDER THE INFLUENCE OF VARYING GRAVITY FIELDS. THIS CAPABILITY WOULD NOT ONLY FOSTER COMPARISON OF MICROGRAVITY TESTING WITH EARTH-BASED TESTING, BUT WOULD ALSO IDENTIFY AT AN EARLY STAGE THE SYSTEMS FOR WHICH COSTLYSPACE EXPERIMENTATION IS NOT WARRANTED. THIS PROPOSAL DESCRIBES A PROGRAM TO DEVELOP A GENERAL PURPOSE MODELING TOOL FOR CVD. THE EFFORT IS BASED ON A CREARE COMPUTER PROGRAM CALLED FLUENT. FLUENT CURRENTLY CAN SIMULATE MANY OF THE DESIRED PHENOMENON, E.G., DIFFUSIONOF MOMENTUM, MASS AND ENERGY, AND CAN ACCOMODATE ARBITRARY 3-D GEOMETRIES AND BOUNDARY CONDITIONS. PHASE I OF THE PROPOSED EFFORT THEREFORE CONSISTS OF ENHANCING FLUENT FOR CVD. IN PARTICULAR, PHASE I WILL ADDRESS A SAMPLE SYSTEM: DEPOSITION OF SILICON FROM SILANE IN A HORIZONTAL FURNACE. COMPARISON WITH PREVIOUS WORK WILL DEMONSTRATE FEASIBILITY. IF RESULTS ARE FAVORABLE, FURTHER ENHANCEMENTS TO MODEL THE GENERAL CVD PROCESS, ALONG WITH EXPERIMENTAL VERIFICATION, WILL BE UNDERTAKEN IN PHASE II.