Patent ID: 7183129
Filing Date: 2007-02-27
Classification: H01L

Abstract:
1. A method for fabricating a CMOS image sensor comprising a low voltage buried photodiode and a transfer translator, the method comprising: a) forming a field oxide for defining an active area and a field area on a certain area of an epitaxial layer formed on a substrate, and forming a gate of the transfer transistor on the active layer of the epitaxial layer; b) forming an ion implantation oxide layer on top of the epitaxial layer between the gate of the transfer transistor and the field oxide, and forming a doping region for the low voltage buried photodiode inside the epitaxial layer between the pate of the transfer transistor and the field oxide; c) forming a sacrificial nitride layer on the whole structure resulting from part b), and forming a spacer insulation layer on the sacrificial nitride layer; d) forming spacers on both sidewalls of the transfer transistor by blanket-etching the spacer insulation layer; and e) removing residual sacrificial nitride from the surface of the photodiode, and forming a floating diffusion region on the other side of the transfer transistor.