Patent ID: 8883544

Claim:
A method of forming an image sensor device, the method comprising: forming a gate stack over a pixel region of a substrate, the pixel region having a front surface defined by a first axis and a second axis perpendicular to the first axis, the gate stack being formed along the first axis on the front surface in the pixel region such that the gate stack has a length X 1 along the first axis and a second length Y 1 along the second axis; forming a mask layer over at least a majority portion of the gate stack and a portion of the front surface to define an active area; and implanting a plurality of dopants with a tilt angle θ into the substrate not covered by the mask layer to form doped isolation features in the pixel region, wherein the doped isolation features surround the active area, and the doped isolation features are formed having a convex portion at least partially under the gate stack.