Advanced computational modeling for growing III-V materials in a high-pressure chemical vapor-deposition reactor

Abstract

A numerical model was developed to simulate vapor deposition in high-pressure chemical vapor-deposition reactors, under different conditions of pressure, temperature, and flow rates. The model solved for steady-state gas-phase and heterogeneous chemical kinetic equations coupled with fluid dynamic equations within a three-dimensional grid simulating the actual reactor. The study was applied to indium nitride (InN) epitaxial growth. The steady-state model showed that at 1050-1290 K average substrate temperatures and 10 atm of total pressure, atomic indium (In) and monomethylindium [In(CH 3 )] were the main group III gaseous species, and undissociated ammonia (NH 3 ) and amidogen (NH 2 ) the main group V gaseous species. The results from numerical models with an inlet mixture of 0.73:0.04:0.23 mass fraction ratios for nitrogen gas (N 2 ), NH 3 and trimethylindium [In(CH 3 ) 3 ], respectively, and an initial flow rate of 0.17 m s -1 , were compared with experimental values. Using a simple four-path surface reaction scheme, the numerical models yielded a growth rate of InN film of 0.027 μm per hour when the average substrate temperature was 1050 K and 0.094 μm per hour when the average substrate temperature was 1290 K. The experimental growth rate under similar flow ratios and reactor pressure, with a reactor temperature between 800 and 1150 K yielded an average growth rate of 0.081 μm per hour, comparing very well with the computed values.