Patent ID: 7323378
Filing Date: 2008-01-29
Classification: H01L

Abstract:
1. A method for fabricating a CMOS image sensor, comprising: providing a semiconductor substrate of a first conductivity type, said semiconductor substrate including a light-sensing region; forming a gate electrode of a transfer transistor of said CMOS image sensor on said semiconductor substrate, wherein an end portion of said gate electrode is adjacent to said light-sensing region; performing a self-aligned ion implantation process to form a diode diffusion region of a second conductivity type in said semiconductor substrate within said light-sensing region; performing an oblique ion implantation process to form a pocket diffusion region of said second conductivity type in said semiconductor substrate directly under said end portion of said gate electrode adjacent to said diode diffusion region; forming a floating diffusion region of said second conductivity type in said semiconductor substrate, said floating diffusion region being disposed at a side of said gate electrode and space-apart from said pocket diffusion region; after forming said diode diffusion region and said pocket diffusion region, forming spacers on sidewalls of said gate electrode; and forming a surface pinning diffusion region of said first conductivity type in said diode diffusion region, wherein said surface pinning diffusion region, said diode diffusion region, said pocket diffusion region and said semiconductor substrate constitute a pinned photodiode.