NUMERICAL MODELING OF PARTICLE FORMATION AND GROWTH DURING CHEMICAL VAPOR DEPOSITION

THERE IS STRONG POTENTIAL FOR IMPROVING THE QUALITY OF THIN FILMS GROWN BY CHEMICAL VAPOR DEPOSITION (CVD) THROUGH PROCESSING IN THE MICROGRAVITY ENVIRONMENT OF SPACE. NUMERICAL MODELING TOOLS WHICH CAN PREDICT IMPORTANT CVD PROCESS BEHAVIOR WOULD ACCELERATE ACHIEVEMENT OF THIS POTENTIAL THROUGH COMPARISON OF THEORY WITH EARTH-BASED TESTING AND EARLY IDENTIFICATION OF SYSTEMS AND PROCESSES FOR WHICH COSTLY SPACE EXPERIMENTATION IS NOT WARRANTED. AN ESPECIALLY IMPORTANT PHENOMENON IN CVD, DUE TO ITS USUALLY DETRIMENTAL IMPACT ON FILM QUALITY, IS PARTICLE FORMATION AND GROWTH IN THE PRECURSOR GAS MIXTURE. THIS PROPOSAL DESCRIBES A PROGRAM TO DEVELOP NUMERICAL MODELING TOOLS TO PREDICT NUCLEATION AND SUBSEQUENT GROWTH OF PARTICLES DURING CVD. THE EFFORT IS BASED ON A COMPUTATIONAL FLUID DYNAMICS COMPUTER PROGRAM CALLED FLUENT WHICH, UNDER A SEPARATE NASA SBIR PROGRAM, HAS BEEN DEVELOPED TO SIMULATE MANY PHENOMENA OF INTEREST TO CVD. THE PHASE I PROGRAM CONSISTS OF IMPLEMENTING MODELS FOR NUCLEATION AND GROWTH IN ORDER TO DEMONSTRATE THAT FLUENT IS A SUITABLE FRAMEWORK FOR GENERAL PURPOSE MODELING. VERIFICATION WILL BE PROVIDED BY COMPARISON OF RESULTS WITH PREVIOUS WORK FROM THE LITERATURE. IF RESULTS ARE FAVORABLE, THE MODELS WILL BE GENERALIZED DURING PHASE II YIELDING SOFTWARE FOR USE BY NASA SCIENTISTS.