Patent ID: 7638351
Filing Date: 2009-12-29
Classification: H01L,Y02E

Abstract:
1. A method of fabricating a photodiode on a semiconductor substrate, the photodiode having a surface having a central region and a peripheral region, comprising: forming an n-type layer on the semiconductor substrate; forming an intrinsic layer on the semiconductor substrate coupled to the n-type layer; forming a p-type layer on the semiconductor substrate coupled to the intrinsic layer; and forming the peripheral region that is concentric with the central region, wherein the peripheral region is optically sensitive to light and the central region is made at least partially optically dead, thereby rendering the photodiode less responsive to incident light on the central region than to incident light on the peripheral region, the incident light including higher order mode groups and lower order mode groups, wherein the peripheral region and the central region are sized and configured such that the lower order mode groups are incident substantially on the central region.