Integrated a ZnSe MSM Photodiode and an InGaP/GaAs HBT on a GaAs Substrate for High Sensitivity Short Wavelength Photodetector

A ZnSe MSM photodiode and an InGaP/GaAs HBT have been integrated successfully on a GaAs substrate by use of the selective-area epitaxy technique. The optical and electrical characterizations of the integrated photoreceiver as well as individual components used in this device structure were estimated. Photocurrent induced from the metal-semiconductor-metal (MSM) photodiode was amplified linearly by a common-emitter circuit composed of a HBT. A current amplification ratio and a voltage amplification sensitivity of the integrated device measured in this work were 20.8 and ${-}29.6$ mV/$mu$ W, respectively. The result does not only demonstrate the high sensitivity monolithic photoreceiver but indicates the potential of the selective-area epitaxy technique in the development of WBG-based short wavelength integrated devices.