Patent ID: 7883926

Claim:
A method for fabricating an image sensor device, comprising: providing a semiconductor substrate having a first and second semiconductor layers stacked over a first surface of the semiconductor substrate, wherein the semiconductor substrate, and the first and second semiconductor layers are formed with same conductivity and with different doping concentrations; forming at least one light-sensing device over or in the second semiconductor layer; forming an interconnect structure over the second semiconductor layer to cover the at least one light-sensing device; bonding a support substrate with the interconnect structure; thinning the semiconductor substrate from a second surface of the semiconductor substrate opposing to the first surface to a first predetermined thickness, said thinning results in a first thinned semiconductor substrate; etching the first thinned semiconductor substrate to a second predetermined thickness, said etching resulting in a second thinned semiconductor substrate; etching the second thinned semiconductor substrate to automatically stop on the first semiconductor layer and expose a surface of the first semiconductor layer; forming a color filter layer over the first surface of the first semiconductor layer; and forming at least one microlens over the color filter layer.