Patent ID: 9681078
Date: 2017-06-13
CPC Classifications: H01L,H04N

Claim:
1. A solid-state image sensor comprising: a charge accumulation region of a first conductivity type; a floating diffusion of the first conductivity type; a stacked semiconductor region which includes a first semiconductor region of a second conductivity type different from the first conductivity type arranged below the charge accumulation region, a second semiconductor region of the second conductivity type arranged above the first semiconductor region, and a third semiconductor region of the second conductivity type arranged above the second semiconductor region; a fourth semiconductor region of the second conductivity type arranged in a region between the charge accumulation region and the floating diffusion, below the floating diffusion, and above the stacked semiconductor region; a transfer gate configured to form a channel, in the fourth semiconductor region, for transferring charges of the charge accumulation region to the floating diffusion; and a fifth semiconductor region of the second conductivity type arranged in a region below the charge accumulation region and the fourth semiconductor region, and above the stacked semiconductor region, wherein with C1 being a peak value of an impurity concentration of the second conductivity type in the first semiconductor region, C2 being a peak value of an impurity concentration of the second conductivity type in the second semiconductor region, C3 being a peak value of an impurity concentration of the second conductivity type in the third semiconductor region, and C5 being a peak value of an impurity concentration of the second conductivity type in the fifth semiconductor region, C2<C3<C1 and C5<C3 are satisfied.