Ciena Corporation
Managing Detection Region Spacing in an Integrated Photodetector

Abstract:

A silicon-on-insulator (SOI) substrate includes a silicon dioxide layer and a silicon layer. A detection region receives a detected optical mode coupled to an incident optical mode defined by an optical waveguide in the silicon layer. The detection region consists essentially of an intrinsic semiconductor material with a spacing structure surrounding at least a portion of the detection region, which comprises p-type, n-type doped semiconductor regions adjacent to first, second portions, respectively, of the detection region. A dielectric layer is deposited over at least a portion of the spacing structure. The silicon layer is located between the dielectric layer and the silicon dioxide layer. First, second metal contact structures are formed within trenches in the dielectric layer electrically coupling to the p-type, n-type doped semiconductor regions, respectively, without contacting any of the intrinsic semiconductor material of the detection region.