Patent ID: 7589349

Claim:
A complementary metal oxide semiconductor (CMOS) image sensor, comprising: a well of a first conductivity type, disposed on a substrate of the first conductivity type; an impurity region for a drive transistor, disposed to cross the well and connected to a power voltage; a first gate electrode of a second conductivity type, connected to the impurity region for the drive transistor; a second gate electrode of the second conductivity type, arranged in parallel to the first gate electrode; and an impurity region of the second conductivity type for a select transistor, connected to the second gate electrode and an output node, wherein the impurity region for the drive transistor is a drain of the drive transistor, and the impurity region for the select transistor is a source of the select transistor, wherein a width of the well between a boundary of the well and a side of gate of the drive transistor formed over the drain of the drive transistor is larger than a width of the well between the other boundary of the well and a side of a gate of the select transistor formed over the source of the select transistor, and wherein a width of the well disposed under the impurity region for the select transistor is in a range from approximately −0.1 μm to approximately −0.33 μm.