Multi-semiconductor layer photodetector and related method

Abstract

A structure includes a photodetector including alternating p-type semiconductor layers and n-type semiconductor layers in contact with each other in a stack. Each semiconductor layer includes an extension extending beyond an end of an adjacent semiconductor layer of the alternating p-type semiconductor layers and n-type semiconductor layers. The extensions provide an area for operative coupling to a contact. The extensions can be arranged in a cascading, staircase arrangement, or may extend from n-type semiconductor layers on one side of the stack and from p-type semiconductor layers on another side of the stack. The photodetector can be on a substrate in a first region, and a complementary metal-oxide semiconductor (CMOS) device may be on the substrate on a second region separated from the first region by a trench isolation. The photodetector is capable of detecting and converting near-infrared (NIR) light, e.g., having wavelengths of greater than 0.75 micrometers.