Improvements on InP epilayers by the use of monoatomic hydrogen during epitaxial growth and successive annealing

Abstract

InP has demonstrated advantages for optoelectronics and wireless applications but there is still a lack of products which offer big InP surfaces for its microelectronics integration. The heteroepitaxy of InP films on cheap and large GaAs substrates would be an appropriate solution for this necessity since bulk InP wafers are available only in small sizes and at high prices [1]. In this way, the challenge for InP growers focuses on finding the best alternatives for avoiding the negative effects produced by the lattice mismatches and the differences in the thermal expansion coefficients between active InP films and substrate materials. Beyond the use of buffer intermediate layers between InP and GaAs, the technique of direct growth of InP on GaAs using monoatomic hydrogen has recently demonstrated excellent results. Compared to homoepitaxial InP layers grown under the same conditions, H-assisted heteroepitaxial InP showed enhanced optical properties. Hydrogen helped to a raise on the critical thickness of 40 times larger than that expected for such a high misfit on InP/GaAs [2].