Study of Encapsulants for Annealing GaAs

摘要: ABSTRACT Low temperature photoluminescence and Auger electron spectroscopy have been used to study chemical-vapor deposited SiO2 SigN4 layers as en- capsulants for high annealing of GaAs. Silicon dioxide or silicon oxynitride allow out-diffusion Ga, while suitably prepared rf plasma SisN4 can be anneal GaAs with negligible Ga out- diffusion. Ion implantation is a versatile method doping semiconductors an established fabrication step many devices (1). Although the use in III-V compounds less wide- spread, important device applications emerged. These include light emitting diodes (2), field-effect transistors, optical waveguid.es, detectors (3). Because difficulties selec- tively other compound by standard diffusion processes compared Si, it now appears that will play increas- ing role future semiconductors. In view potential this method, develop reliable procedures im- plantation these materials. produces considerable lattice damage which must annealed out order restructure activate implanted impurities. While pro- cedure relatively straightforward semiconductor such more difficult. The incongruent evaporation As from at temperatures ~ excess 600~ (4) makes impossible bare samples without surface degradation. It thus necessary encapsulate sample suitable dielectric layer perform carefully controlled ambient (5. 6). There numerous discussions using encapsu- lants sputtered chemical,vapor (7), thermally o r reactively sput- tered Si3N4 (8-10), A1N (11). present work we low photo- luminescence (PL) _(AES) investigate annealing-encapsulation properties chemical vapor Si.~N4 on well known experiments Si has very coefficient (12). Gyulai et