Patent ID: 8153465

Claim:
A method for manufacturing an image sensor, the method comprising: forming a readout circuitry on a first substrate; forming an interlayer dielectric on the first substrate forming an interconnection in the interlayer dielectric, the interconnection being electrically connected to the readout circuitry; providing a second substrate with an image sensing device, the image sensing device comprising a first conductive type layer and a second conductive type layer; bonding the second substrate on the interlayer dielectric; removing a portion of the second substrate that does not include the image sensing device; and performing a first wet etch process on an exposed surface of the image sensing device after removing a portion of the second substrate; removing a portion of the second conductive type layer of the image sensing device to form a first via hole; forming a sidewall dielectric on a sidewall of the second conductive type layer in the first via hole; removing a portion of first conductive type layer and the interlayer dielectric using the sidewall dielectric as an etch to form a second via hole exposing the interconnection; and forming a contact plug electrically connecting the first conductive type layer to the interconnection through the second via hole.