REACTION-KINETICS OF SILICON-CARBIDE DEPOSITION BY GAS-SOURCE MOLECULAR-BEAM EPITAXY

Thin films of silicon carbide (SiC) have been grown at 1000-1500 degre es C on vicinal and on-axis alpha(6H)-SiC(0 0 0 1) substrates by gas-s ource molecular-beam epitaxy (GSMBE). Growth on on-axis and off-axis 6 H-SiC(0 0 0 1) substrates using the SiH4-C2H4 system resulted in 3C-Si C(1 1 1) epilayers under all conditions of reactant gas flow and tempe rature. By adding H-2 to the SiH4-C2H4 system, films of 6H-SiC(0 0 0 1 ) were deposited on vicinal 6H-SiC substrates at deposition temperatur e greater than or equal to 1350 degrees C. Kinetic analysis of the dep osition of 3C-SiC films with respect to reactant inputs and growth tem perature is presented. From the data, the deposition of 3C-SiC appears to be surface-reaction-controlled. Reflection high-energy electron di ffraction (RHEED) and high-resolution transmission electron microscopy (HRTEM) was used to determine the crystalline quality, surface charac ter and epilayer polytype. (C) 1998 Elsevier Science B.V. All rights r eserved.