Abstract: A device is disclosed. The device includes a plurality of pixels disposed over a first surface of a semiconductor layer. The device includes a device layer disposed over the first surface. The device includes metallization layers disposed over the device layer. One of the metallization layers, closer to the first surface than any of other ones of the metallization layers, includes at least one conductive structure. The device includes an oxide layer disposed over a second surface of the semiconductor layer, the second surface being opposite to the first surface, the oxide layer also lining a recess that extends through the semiconductor layer. The device includes a spacer layer disposed between inner sidewalls of the recess and the oxide layer. The device includes a pad structure extending through the oxide layer and the device layer to be in physical contact with the at least one conductive structure.

Abstract: A two-step etch technique is used in a continuous polysilicon on oxide definition edge (CPODE) recess process to form a recess in which the CPODE structure is to be formed. The two-step process includes performing a first etch operation using an isotropic etch technique, in which a recess in a dummy gate structure is formed to a first depth. A second etch operation is performed using anisotropic etch technique to form the recess to a second depth. The use of the anisotropic etch technique results in a highly directional (e.g., vertical) etch of the dummy gate structure in the second etch operation. The highly directional etch provided by the anisotropic etch technique at or near the bottom of the dummy gate structure reduces, minimizes, and/or prevents etching into adjacent portions of an interlayer dielectric (ILD) layer and/or into source/drain region(s) under the portions of the ILD layer.