Growth mode control of InGaN on GaN by using SiH4 post-treatment

Abstract

We report on a way to control the growth mode of an In0.43Ga0.57N layer on GaN by using SiH4 post-treatment. In0.43Ga0.57N islands were formed on the GaN layers by a using Stranski-Krastanov growth mode without SiH4 post-treatment. When the SiH4 flow rate was increased from 0 to 10 sccm, the InGaN island density decreased from 3.3 × 109 to 1.9 × 109 then to zero, resulting in two-dimensional growth. However, a further increase in the SiH4 flow rate to 15 sccm again led to the formation of InGaN islands. Temperature- and excitation-power-dependent photoluminescence spectra showed that the InGaN islands provided strong localized recombination centers for electrical charge carriers and that the InGaN layers were composed of InGaN islands with different numbers of monolayers. This abnormal growth behavior with SiH4 post-treatment was explained by the combined effects of surfactant-mediated growth modification and the formation of Si x N y with the injection of SiH4.