Patent ID: 7510904

Claim:
A method of fabricating a semiconductor photodetector, the method comprising the steps: forming a semiconductor structure comprising a single-crystal semiconductor substrate; a second layer of an insulating material, and a third layer comprising essentially Si; growing epitaxially a fourth layer of essentially Ge, the fourth layer having a surface layer; annealing to reduce threading dislocation density; forming isolation regions surrounding said third layer and said fourth layer, said isolation regions having a top border adjacent to or above said fourth layer and a bottom border adjacent to said second layer; forming alternating stripes of p-type and n-type doped material adjacent to said surface layer such that regions of non-intentionally-doped material remain between said alternating stripes; and forming a set of electrodes on said surface layer comprising a plurality of interdigitated members, wherein the entirety of the portion of said electrodes that is in contact with said surface layer also is in contact with said stripes of p-type and n-type doped material.