Patent ID: 7361528

Claim:
A method of fabricating a germanium infrared sensor for a CMOS imager, comprising: preparation of a donor wafer, including: preparation of a silicon wafer; ion implantation into the silicon wafer to form a P+ silicon layer; growing an epitaxial germanium layer on the P+ silicon layer, forming a silicon-germanium interface; cyclic annealing to form a layer of high density of defects on the germanium side of the silicon-germanium interface and to diffuse ions from the P+ silicon layer into the high defect density region of the germanium layer forming a P+ germanium layer; and implanting hydrogen ions to a depth at least as deep as the P+ silicon layer to form a defect layer; preparing a handling wafer, including: preparing a silicon substrate; fabricating a CMOS integrated circuit on the silicon substrate; depositing a layer of passivation oxide on the CMOS integrated circuit; forming contact holes; depositing metal and smoothing the metal by CMP to from metal plugs in the contact holes; depositing a layer of refractory metal; treating the surfaces of the donor wafer and the handling wafer for bonding; bonding the handling wafer and the donor wafer to form a bonded structure; splitting the bonded structure along the defect layer; depositing a layer of indium tin oxide on the germanium layer; completing the IR sensor.