SEMICONDUCTOR PHOTODETECTOR

摘要

A photodetector for the detection of a light beam comprises a metal layer (101) acting as a ground plane, a semiconductor layer (102) covering the metal layer, wherein the semiconductor layer is made of at least two different materials forming a heterostructure adapted for generating a detection current by absorbing the light beam bringing electrons from a fundamental state to an excited state, an array of metal pads (103) covering the semiconductor layer, collecting the light beam and directing it towards the semiconductor layer. Each of the metal pads together with the metal layer (101) forms an antenna structure which increases the effective collection surface and a plasmonic resonator of vertical cavity type so that the thickness of the photodetector can be made inferior to a wavelength of the light beam to be detected. The semiconductor layer (102) is removed by etching in the areas of the semiconductor layer that are not covered by a metal pad. Thereby, the ratio between the detection current and the dark current is greatly improved and thus the background limited infrared performance (BLIP) temperature is increased.