Patent ID: 9711547
Date: 2017-07-18
CPC Classifications: H01L

Claim:
1. An image pickup apparatus comprising: a plurality of pixels, wherein at least one of the plurality of pixels includes: a photoelectric conversion unit; a reset transistor; a floating diffusion region; an amplification transistor configured to amplify a signal based on charges generated by the photoelectric conversion unit; and a capacitance that has a PN junction constituted by a first semiconductor region having a first conductivity type and a second semiconductor region having a second conductivity type and can accumulate the charges; wherein the one of the plurality of pixels is configured to change a capacitance value of an input node of the amplification transistor by switching a connection state of the capacitance, wherein a switching transistor is configured to switch a connection state of the capacitance with the input node of the amplification transistor, wherein a gate electrode of the amplification transistor is arranged on a main surface of a semiconductor substrate, and a third semiconductor region having the second conductivity type is arranged under the gate electrode of the amplification transistor, and wherein an added impurity concentration of impurity having the second conductivity type on the PN junction surface of the capacitance is higher than an added impurity concentration of impurity having the second conductivity type at a point in the third semiconductor region, the point being at a same depth as a bottom of one of a source and a drain of the amplification transistor.