Patent ID: 8624310

Claim:
An image sensor, comprising: a substrate including a light-receiving region and a non-light-receiving region defined in the substrate; a transfer gate formed on the non-light-receiving region and spacers formed on both side walls of the transfer gate; an n-type first dopant region of a pinned photodiode formed in the light-receiving region; a p-type second dopant region of the pinned photodiode formed on a surface of the light-receiving region, the second dopant region of the pinned photodiode including, a lower-concentration dopant region formed to be aligned to the transfer gate, and a higher-concentration dopant region formed to be aligned to one of the spacers; and a plurality of negative-channel metal-oxide semiconductor (NMOS) transistors provided to the non-light-receiving region, wherein the NMOS transistors include source, drain, or source and drain regions including n-type and p-type dopants, the source, drain, or source and drain regions are not formed in a well, the n-type dopant has a concentration higher than the p-type dopant, and the substrate includes, a bulk substrate, a well formed on the bulk substrate, and an epi layer formed on the well, the well has same conductivity with the substrate and the epi layer has same conductivity with the substrate.