Patent ID: 7361526

Claim:
A method of fabricating a germanium photo detector comprising: preparing a silicon substrate wafer; depositing and planarizing a silicon oxide layer; forming contact holes in the silicon oxide layer which communicate with the underlying silicon substrate; selectively growing an epitaxial germanium layer of a first type on the silicon oxide layer and in the contact holes; forming another germanium layer of the first type on the epitaxial germanium layer and the silicon oxide layer by epitaxial lateral overgrowth (ELO); smoothing and thinning the ELO germanium layer of the first type by chemical mechanical polishing; growing an intrinsic germanium layer on the ELO germanium layer of the first type and on any exposed silicon oxide layer; forming a germanium layer of a second type on the intrinsic germanium layer; depositing a silicon oxide overcoat over the wafer; opening a window through the silicon oxide overcoat to the germanium layer of the second type; depositing a layer of conductive material on the silicon oxide overcoat and in the windows therein; and etching the conductive material to form individual sensing elements.