Patent ID: 8022390
Filing Date: 2011-09-20
Classification: H01L

Abstract:
1. A photodetector for detecting infrared light, comprising: a semiconductor substrate; a plurality of semiconductor layers epitaxially grown on the semiconductor substrate, with the plurality of semiconductor layers including a lower cladding layer, a type-II superlattice region, and an upper cladding layer; a mesa structure formed from the plurality of semiconductor layers, with the mesa structure having a plurality of outer sidewalls, and with the mesa structure having a central portion in the center of the photodetector which is etched downward at least partway through the type-II superlattice region to form an inner sidewall of the mesa structure; an electrically-insulating layer deposited over a top surface of the mesa structure; a first impurity-doped region extending into the mesa structure from the inner sidewall of the mesa structure; a second impurity-doped region extending into the mesa structure from at least one of the outer sidewalls of the mesa structure; a first electrode deposited over the inner sidewall of the mesa structure and extending over the top surface of the mesa structure above the electrically-insulating layer; and a second electrode deposited over the second impurity-doped region.