Patent ID: 7659564
Filing Date: 2010-02-09
Classification: H01L

Abstract:
1. A pixel sensor cell comprising: a semiconductor substrate; and a photosensitive element within the semiconductor substrate, the photosensitive element including: a trench in the semiconductor substrate, wherein the semiconductor substrate comprises a first doped region of a first conductivity and a second doped region of the first conductivity at an upper surface of the semiconductor substrate, in which the first doped region is on an opposing side of the trench as the second doped region; a boundary layer of the first conductivity present in the sidewalls and base of the trench; a collector region of a second conductivity present in the substrate below the first and second doped regions of the first conductivity and abutting the boundary layer of the first conductivity, wherein the boundary layer and the first and second doped regions of the first conductivity isolate the collector region of the second conductivity from the sidewalls of the trench and the upper surface of the semiconductor substrate; and a fill material of the first conductivity present in the trench.