High sensitivity and no-cross-talk pixel technology for embedded CMOS image sensor

Abstract

A high-photosensitivity and no-cross-talk pixel technology has been developed for an embedded active-pixel CMOS image sensor using a 0.35-/spl mu/m CMOS logic process. To increase photosensitivity, we developed a deep low-concentration p-well (deep p-well) photodiode. To suppress pixel cross-talk caused by obliquely incident light, a double-metal photoshield was used. The cross-talk caused by electron diffusion in the substrate was suppressed by using the deep p-well photodiode. A 1/3-inch 330 k-pixel active-pixel CMOS image sensor was fabricated using this technology. A sensitivity improvement of 110% for 550-nm incident light was obtained.