Patent ID: 7176532

Claim:
An active pixel sensor, comprising: a substrate formed of P type epitaxial silicon; an N well formed in said substrate wherein said N well is formed of N type silicon; a P well formed in said substrate wherein said P well has an inner periphery and an outer periphery, surrounds said N well, and is formed of P type silicon; an N + region formed in said N well, wherein the entire said N + region is within said N well and does not extend beyond said N well; a P + region formed in part of said P well and part of said substrate wherein said P + region extends from within said P well into said substrate toward said N well, thereby leaving a gap between said P + region and said N well; a layer of gate dielectric formed over said gap, said N well, said N + region, and at least part of said P + region; and a gate electrode formed on said layer of gate dielectric over said gap, at least part of said N well, and at least part of said P + region.