Epitaxial growth of germanium photodetector for CMOS imagers

摘要

A method of fabricating a germanium photodetector includes preparing a silicon wafer as a silicon substrate; depositing a layer of silicon nitride on the silicon substrate; patterning and etching the silicon nitride layer; depositing a first germanium layer on the silicon nitride layer; patterning and etching the germanium layer wherein a portion of the germanium layer is in direct physical contact with the silicon substrate; depositing a layer of silicon oxide on the germanium layer wherein the germanium layer is encapsulated by the silicon oxide layer; annealing the structure at a temperature wherein the germanium melts and the other layers remain solid; growing a second, single-crystal layer of germanium on the structure by liquid phase epitaxy; selectively removing the silicon oxide layer; and completing the germanium photodetector.