NASA 1996 SBIR Phase I

PROJECT TITLE : MONTE CARLO MODELING OF SURFACE MORPHOLOGY DURING SiC FILM GROWTH

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

The technological usefulness of a material is determined in part by the compositional and morphological uniformity attained during growth. When films are deposited on a surface, the resulting morphology can change drastically depending on the operating parameters of the reactor and the preparation of the surface to be altered. Although the resulting morphologies give insight as to how the materials grow or are etched, in many instances the exact mechanism or reaction pathways by which the resulting film is achieved is not fully understood.

In the Phase I study, a Monte Carlo (MC) model will be developed to better understand the mechanisms, reaction pathways and the resultant surface morphology during SiC growth. The MC model will be developed to include n- nearest neighbor scope, surface energy, and improvements in the adatom movement algorithm. The new adatom movement algorithm will take into account the temperature effect on residence time, the surface energy, awareness of empty space in the lattice, and identity of adsorbed adatom and lattice atoms.

The modified model will elucidate how the operating temperature, atom face (Si or C), and wafer polytypes affect film morphology. Step bunching during step flow growth will also be explored. In Phase II the MC model will be extended to allow for variation of bond direction and have a more general treatment of polytype in the lattice data structure. These improvements will allow for the study of 3C-inclusions and impediments to step-flow growth such as growth pits, dislocations, micropipes, and dislocation loops.

This project will produce a model that will help identify microscopic and acroscopic conditions necessary for obtaining desired SiC morphologies and composition. This computational tool will be valuable in designing processing conditions for the production of high quality SiC films for applications in areas such as high temperature devices.

Dr. P. J. Stout
CFD Research Corporation
3325 Triana Blvd.
Huntsville, AL 35805

Dr. P. J. Stout
CFD Research Corporation
3325 Triana Blvd.
Huntsville, AL 35805