Patent ID: 8071417

Claim:
A method for fabricating an image sensor, comprising: forming a readout circuit in a semiconductor substrate; forming an interconnection connected to the readout circuit on the semiconductor substrate; forming a dielectric interlayer on the semiconductor substrate, covering the interconnection; forming an image sensing unit including a stack of a first impurity region and a second impurity region on the dielectric interlayer; forming a via hole piercing the image sensing unit and the dielectric interlayer to expose the interconnection; and forming a bottom electrode in the via hole to electrically connect the interconnection and the first impurity region of the image sensing unit, wherein the forming of the bottom electrode comprises: forming an electrode layer along surfaces of the via hole and the image sensing unit; forming a hard mask layer along the surface of the electrode layer; forming a photoresist pattern on the hard mask layer to fill only a portion of the via hole; forming a hard mask by selectively etching the hard mask layer through an etch process using the photoresist pattern as an etch mask; exposing the second impurity region by selectively etching the electrode layer through an etch process using the hard mask as an etch mask; and removing the hard mask.