CMOS IMAGE SENSOR AND METHOD FOR FABRICATING THE SAME

摘要

A CMOS image sensor and a manufacturing method thereof are provided to reduce a dark current and to improve an image lag by separately forming a pocket photo diode related to a main photo diode and a charge transfer. A transfer transistor(Tx) has a transfer gate(132) on a first conductive-type semiconductor substrate(100) and a channel region(112). The channel region has a first conductive-type impurity ion implantation layer located in the semiconductor substrate at a lower portion of the transfer gate. A photo diode includes a second conductive-type main photo diode(140) in the semiconductor substrate and a second conductive-type pocket photo diode(142). The second conductive-type pocket photo diode is located between the channel region and the main photo diode. The channel region includes a second conductive-type impurity ion implantation layer at a lower portion of the first conductive-type impurity ion implantation layer. A first conductive-type diffusion layer(144) is formed on a surface of the main photo diode.