利用低压金属有机化学气相沉积技术, 开展InP/GaAs异质外延实验。由450 ℃生长的低温GaAs层与超薄低温InP层组成双异变缓冲层, 并进一步在正常InP外延层中插入In1-xGaxP/InP(x=7.4%)应变层超晶格。在不同低温GaAs缓冲层厚度、应变层超晶格插入位置及应变层超晶格周期数等条件下, 详细比较了InP外延层(004)晶面的X射线衍射谱, 还尝试插入双应变层超晶格。实验中, 1.2 μm和2.5 μm厚InP外延层的ω扫描曲线半峰全宽仅370 arcsec和219 arcsec; 在2.5 μm厚InP层上生长了10周期In0.53Ga0.47As/InP 多量子阱, 室温PL谱峰值波长位于1625 nm, 半峰全宽为60 meV。实验结果表明, 该异质外延方案有可能成为实现InP-GaAs单片光电子集成的一种有效途径。

Heteroepitaxy of InP on GaAs substrates by LP-MOCVD has been investigated experimentally. Low temperature (LT) GaAs and ultrathin LT InP buffer layers are grown at 450 ℃, which had composed the double metamorphic buffers together. In addition, In1-xGaxP/InP(x=7.4%) strained layer superlattices (SLSs) have been inserted into the normal InP epilayers. XRD curves of InP epilayers in (004) reflection have been compared under different thicknesses of LT GaAs buffer, different insertion positions and different periods of single InGaP/InP SLS. Insertion of double SLSs into InP epilayer has also been tried. In this experiment, the full width at half maximum (FWHM) values of XRD ω scan curves are only 370 arcsec and 219 arcsec for 1.2 μm and 2.5 μm-thick InP epilayers, respectively. Subsequently, 10-period In0.53Ga0.47As/InP MQW structure has been deposited on 2.5 μm-thick InP epilayer, the peak wavelength of room-temperature PL spectrum was located at 1625nm with the FWHM value of only 60 meV. Experimental results indicate that the heteroepitaxy scheme described in this paper would become a potential approach to realize the monolithic optoelectronic integration between InP and GaAs.