| 摘要 |
A CMOS photodetector pixel formed of a substrate, an epitaxial layer above the substrate including a first region having the same polarity but a lower impurity concentration as that of the substrate, and a gate arrangement including a first gate that forms a charge accumulation region in the epitaxial layer when the gate is energized, wherein the charge accumulation region extends deeper toward the substrate than in conventional constructions. The epitaxial layer includes a shielding structure for absorbing electrons generated therein by photons impinging on the pixel, except electrons generated close to the charge accumulation region. The shielding structure may have opposite polarity from that of the substrate, including a first portion under the first gate, and a second portion extending upward from the first portion at the margin of the pixel. Alternatively, the shielding structure may have the same polarity as the substrate, but a lower impurity concentration. |
