The invention relates to a method for manufacturing a
CMOS (complementary
metal-
oxide-
semiconductor transistor)
image sensor, wherein the method comprises the steps of: forming a
photodiode with a common structure; and controlling an
ion injecting angle, carrying out a plurality of times of
ion injection on set areas of the
photodiode, wherein the areas subjected to the plurality of times of
ion injection are partially overlapped, so that at least one trench is formed among the set areas of the
photodiode and the trench comprises areas with maximal
doping concentration in transverse directions of the photodiode vertical to an axial direction. In the method for manufacturing the
CMOS image sensor, the plurality of times of ion injection are carried out on the photodiode and the ion injecting angle is adjusted, thus the trench with the
doping concentration greater than of that of the other areas of the photodiode is formed in the photodiode; and the trench comprises the areas with the maximal
doping concentration, so that photoelectrons are effectively driven to move, the quantity of the delayed photoelectrons is reduced, the
transfer efficiency of the photodiode is improved, and the phenomenon of image
delay or
information loss is reduced.