Germanium photo detector having planar surface through germanium epitaxial overgrowth

摘要

A method of fabricating a germanium photo detector includes preparing a silicon substrate wafer and depositing and planarizing a silicon oxide layer on the silicon substrate. Contact holes are formed in the silicon oxide layer. An N+ epitaxial germanium layer is grown on the silicon oxide layer and in the contact holes. An N+ germanium layer is formed by ELO. The structure is smoothed and thinned. An intrinsic germanium layer is grown on the N+ epitaxial germanium layer. A P+ germanium layer is formed on the intrinsic germanium layer and a silicon oxide overcoat is deposited. A window is opened through the silicon oxide overcoat to the P+ germanium layer. A layer of conductive material is deposited on the silicon oxide overcoat and in the windows therein. The conductive material is etched to form individual sensing elements.