Physics and Technology of III-V Pseudomorphic Structures

摘要

We have shown that pseudomorphic InAsP on InP is a viable alternative to theconventional InGaAsP for long wavelength optical fiber communications. The layer thickness and composition are independently controlled in gas source molecular beam epitaxy. We developed, for the first time, an in situ technique for composition calibration in growing InAsP by group III and group V induced intensity oscillations of reflection high energy electron diffraction. By a systematic growth optimization procedure with respect to growth temperature, V/III incorporation ratio and substrate misorientation, high quality InAsP/InP strained multiple quantum wells were successfully grown on both InP(111)B and (100) substrates. The valence band offset was obtained from the best fit of a model calculation to the photoluminescence excitation spectra. Excellent electroabsorption and photocurrent spectra were obtained for 1.3 micron InAsP/InP MQW modulator structures. We have also developed a growth kinetic model for composition control on InGaAsP. In addition, besides pseudomorphic phosphide base heterostructures on InP, we have obtained very good results from the use of a linearly graded buffer layer for growing lattice mismatched phosphide base heterostructures on GaAs substrates.