Patent ID: 9640570
Date: 2017-05-02
CPC Classifications: H01L

Claim:
1. A method of manufacturing a solid-state image sensor, including a charge accumulation region of a first conductivity type formed on a semiconductor substrate, a first charge holding region of the first conductivity type formed on the semiconductor substrate, a first transistor configured to transfer charges from the charge accumulation region to the first charge holding region, a second charge holding region of the first conductivity type formed on the semiconductor substrate, and a second transistor configured to transfer the charges from the first charge holding region to the second charge holding region, the method comprising: forming, on the semiconductor substrate, a first resist pattern having a first opening on the charge accumulation region; injecting a first impurity of a second conductivity type via the first opening so as to make the charge accumulation region be a buried type; forming, on the semiconductor substrate, a second resist pattern having a second opening on the first charge holding region; and injecting a second impurity of the second conductivity type via the second opening so as to make the first charge holding region be the buried type, wherein, in the injecting the first impurity, the first impurity is injected in a first direction inclined toward a normal to an upper surface of the semiconductor substrate and headed from a side of the first charge holding region to a side of the charge accumulation region, and, in the injecting the second impurity, the second impurity is injected in a second direction inclined toward the normal and headed from a side of the second charge holding region to the side of the first charge holding region.