PURPOSE: To enable a high-resistance layer in a re-growth interface of an InGaAs semiconductor to be reduced by forming a highly dense n-type impurities layer and an n-type active layer with InGaAs semiconductor and then equalizing the mixed crystal ratio of InAs at the interface.
CONSTITUTION: Be is doped as impurities onto a p-type In0.2Ga0.8As layer 3 by 3.0×1016/cm2 for forming a thickness of 3000. Si is doped as impurities onto an n-type In0.2Ga0.8As active layer 4 by 1.5×1019/cm2 for forming a thickness of 500. An undoped Al0.3Ga0.7As layer 5 is 100 thick and GaAs layer 6 is 50 thick. Then, after depositing an SiO2 film 36 on an entire surface, wet etching of the SiO2 film 36, the undoped GaAs layer 6, and the undoped Al0.3Ga0.7As layer 5 is performed. This wet etching process allows the n-type In0.2Ga0.8As active layer 4 to be exposed and may eliminate one part of the layer 4 in terms of wet etching depth.
HIRUMA TAKEYUKI
YAZAWA MASAMITSU
UMEMOTO YASUNARI
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