FABRICATION METHOD OF IMAGE SENSOR HAVING PINNED PHOTODIODE

摘要

PURPOSE: A fabrication method of an image sensor having a pinned photodiode is to enhance optical sensitivity and depress the potential barrier formed at the channel region of the transfer transistor. CONSTITUTION: A fabrication method of an image sensor comprises the steps of: providing a semiconductor layer(11) having a first conductive type; forming an isolation insulating layer(13) and a gate electrode(15) of a CMOS(Complementarily metal oxide semiconductor) transistor on the semiconductor layer; forming a first ion-implanted layer(16) having a second conductive type opposite to the first conductive type in the semiconductor layer of where a pinned photodiode is being formed; forming a mask pattern(20) in which an upper portion of the first ion-implanted layer and an edge of the insulating isolation layer are exposed; etching exposed portion of the insulating isolation layer using the mask as etch stopper; and forming a second ion-implanted layer(21) having the first conductive type below the exposed surface of the semiconductor layer using the mask as ion implanting barrier.