Patent ID: 7749796

Claim:
A method for manufacturing a solid state image pickup device in which a semiconductor substrate includes (a) a pixel region where (1) a plurality of pixels are arranged, each pixel including a signal charge accumulating portion and a transistor, and (2) a pixel well of a first conductive type shared by the respective pixels is positioned and (b) a peripheral circuit region outside the pixel region, the peripheral circuit region including a first peripheral well of a second conductive type, and a region of the first peripheral well includes a MIS transistor of the first conductive type, the method comprising: a first step of forming a first impurity doped region on the pixel well by ion-implanting an impurity of the first conductive type to a surface of the pixel well at a surface density of 1×10 14 cm −2 or less in total; a second step of forming an interlayer film after the first step; a third step of forming a hole for providing a contact electrode in the interlayer film on the first impurity doped region; a fourth step of forming a contact portion by ion-implanting an impurity of the first conductive type through the hole; a fifth step of forming the contact electrode by filling the hole; and a sixth step of performing ion implantation on a source/drain of the MIS transistor at a surface density of more than 1×10 14 cm −2 before the second step and after masking the first impurity doped region.