借助超薄低温InP缓冲层,在GaAs衬底上生长出了高质量的InP外延层,在InP外延层中插入了15周期In0.93Ga0.07P/InP应变层超晶格(SLS),进一步阻断了失配位错穿透到晶体表面,提高了外延层的晶体质量,这样2.5μm厚InP外延层的双晶X射线衍射(DCXRD)ω扫描半高全宽(FWHM)值降低至219arcsec,该InP外延层的室温光荧光(PL)谱线宽度仅为42meV。在此基础上,只利用超薄低温InP缓冲层技术就在半绝缘GaAs衬底上成功地制备出了长波长异变In0.53Ga0.47AsPIN光电探测器,器件的台面面积为50μm×50μm,In0.53Ga0.47As吸收层厚度为300nm,在3V反偏压下器件的3dB带宽达到了6GHz,在1550nm波长处器件的响应度达到了0.12A/W,对应的外量子效率为9.6%。
High-quality InP epilayers were grown on GaAs substrates by using the ultrathin low temperature InP buffer layer. A 15-period In0. 93 Ga0. 07 P/InP strained layer superlattice(SLS) was inserted into the normal InP layers, which blocked the vertical propagation of theading dislocat5ion and further improved the crystal quality of InP epilayer. The DCXROω san full width at half maximum (FWHM) of 219 arcsec and the room-temperature PL linewidth of 42 meV were obtained for 2. 5μm-thick InP epilayer. Additonally, the long-wavelength metamorphic In0. 53 Gao. 47 As PIN photodetectors grown on semi insulating GaAs substrates were sucessfully demonstrated by low temperautre InP buffer technology. The active area of this photodetector was 50 μm×50 μm,and the thickness of In0. 53 Gao. 47 As adsorption layer was 300 nm The 3 dB bandwidth of frequency response reached 6 GHa The responsivity of 0. 12 A/W to 1 550 nm optical radiation, corresponding to the external quantum efficiency of 9.6%, was achieved.