Patent ID: 6329233
Filing Date: 2001-12-11
Classification: H01L

Abstract:
A method for manufacturing a photodiode CMOS image sensor, comprising the steps of:providing a first type substrate;forming a first type well and a second type well in the first type substrate;forming a plurality of isolation layers over the first type well, the second type well and the first type substrate so that an active region for forming a second type MOS transistor, an active region for forming a first type MOS transistor and an active region for forming a photodiode are patterned out;forming a protective ring layer on the peripheral area of the active region for forming the photodiode;forming a first gate structure over the active region for forming the first type MOS transistor and a second gate structure over the active region for forming the second type MOS transistor;forming a second type source/drain region in the first type well on each side of the first gate structure and a second type heavily doped layer in the first type substrate enclosed by the protective ring layer;forming a first type source/drain region in the second type well on each side of the second gate structure; andconducting a high-energy ion implantation to form a second type lightly doped layer ringing around the second type heavily doped layer in the first type substrate, wherein thickness of the second type lightly doped layer is much greater than the second type heavily doped layer.