Patent ID: 7633134
Filing Date: 2009-12-15
Classification: H01L

Abstract:
1. A photodiode for a pixel of a complementary metal oxide semiconductor (CMOS) image sensor, comprising: a semi-conductive layer of a first conductivity type; multiple doping regions of a second conductivity type formed to different depths in the semi-conductive layer; multiple doping regions of the first conductivity type formed between the multiple doping regions of the second conductivity type and forming multiple junction capacitances without full depletion when a bias voltage is applied to deplete the photodiode; a pinning layer formed underneath a surface of an oxide layer; and a counter doping region formed in a portion of one of the multiple doping regions of the first conductivity type and provides a contiguous connection between the multiple doping regions of the second conductivity type disposed above and under the one of the multiple doping regions of the first conductivity type, wherein the multiple doping regions of the first conductivity type and the multiple doping regions of the second conductivity type are surrounded by a n-type doping region.