Abstract

Metal-semiconductor-metal (MSM) photodetectors are important components in high speed photoreceivers for optical link applications due to their ease of fabrication and process compatibility with fieldeffect transistors.¹ Being an interdigitated Schottky contact structure, the performance of MSM device will be determined by the interface quality between the deposited metal and semiconductor surface. Burroughes² showed that the AlGaAs capping layer can effectively passivate GaAs surface in GaAs MSM device. However, the oxidation of AlGaAs will cause performance degradation and affect its long term reliability. The high bandgap aluminum-free In_0.49Ga_0.51P (InGaP) material with low surface recombination velocity³ is applied, in this study, to replace the AlGaAs to fabricate the high reliability MSM photodetectors.

© 1995 IEEE