High Performance InGaAs/GaAs Strained Layer Superlattice Photodetectors Compatible with GaAs MESFET Technology

Abstract

A high performance long-wavelength interdigitated metal-semiconductor-metal (MSM) photodetectors is reported in this paper. The photoabsorbing layer consists of an InGaAs/GaAs strained layer superlattice designed for light absorption in the long wavelength region. The structure, grown on a GaAs undoped substrate, is fully compatible with the technology of the mature GaAs electronic devices. The MSM photodiodes exhibit a very low dark current, 26 nA at 10 V applied bias, a very fast pulse response with a deconvoluted full width at half maximum of about 13 ps at 10 V applied bias, corresponding to an intrinsic bandwidth of about 35 GHz.