US Patent 7354841 Method for fabricating photodiode of CMOS image sensor

A method for fabricating a photodiode of a CMOS image sensor is disclosed, to improve a charge accumulation capacity in the photodiode, which includes the steps of defining a semiconductor substrate as an active area and a field area by forming an STI layer; firstly implanting impurity ions for formation of the photodiode to the semiconductor substrate of the active area; secondarily implanting impurity ions for formation of the photodiode to the semiconductor substrate being adjacent to the STI layer; and forming a photodiode ion-implantation diffusion layer by diffusing the implanted impurity ions with a thermal process.