Nucleation Layer의 표면 거칠기가 GaAs 기판 위에 성장된 InP 에피층의 품질에 미치는 영향

Abstract

Department of Electronic Engineering, Cheongju University, Cheongju 360-764, Korea(Received July 4, 2012; Revised July 11, 2012; Accepted July 12, 2012)Abstract: Heteroepitaxial InP films have been grown on GaAs substrates to study the effects of the nucleation layer's surface roughness on the epitaxial layer's quality. For this, InP nucleation layers were grown at 400℃ with various ethyldimethylindium (EDMIn) flow rates and durations of growth, annealed at 620℃ for 10 minutes and then InP epitaxial layers were grown at 550℃. It has been found that the nucleation layer's surface roughness is a critical factor on the epitaxial layer's quality. When a nucleation layer is grown with an EDMIn flow rate of 2.3 μmole/min for 12 minutes, the surface roughness of the nucleation layer is minimum and the successively grown epitaxial layer's qualities are comparable to those of the homoepitaxial InP layers reported. The minimum full width at half maximum of InP (200) x-ray diffraction peak and that of near-band-edge peak from a 4.4 K photoluminescence are 60 arcmin and 6.33 meV, respectively.Keywords: InP, Heteroepitaxy, Surface roughness, Nucleation layer