CMOS pixel sensor with depleted photocollectors and a depleted common node

摘要

An active pixel sensor in a p-type semiconductor body includes an n-type common node formed below a pinning region. A plurality of n-type blue detectors more lightly doped than the common node are disposed below pinning regions and are spaced apart from the common node forming channels below blue color-select gates. A buried green photocollector is coupled to the surface through a first deep contact spaced apart from the common node forming a channel below a green color-select gate. A red photocollector buried deeper than the green photocollector is coupled to the surface through a second deep contact spaced apart from the common node forming a channel below a red color-select gate. A reset-transistor has a source disposed over and in contact with the common node. A source-follower transistor has gate coupled to the common node, a drain coupled to a power-supply node, and a source forming a pixel-sensor output.