Solid state imaging device having high-sensitivity and low-noise characteristics by reducing electrostatic capacity of interconnection

摘要

There is provided a solid state imaging device having high-sensitivity, low-noise characteristics by reducing electrostatic capacity relating to interconnection. The solid state imaging device includes a photoelectric conversion section (21), a transfer section (22), a floating diffusion layer (51) for receiving signal charges from the transfer section (22), and an output transistor (T1) having a gate electrode (18) connected to the floating diffusion layer (51) via an interconnection. A source (19a) and a drain (19b) of the output transistor (T1) are provided commonly within a flat p-type well (13) of relatively thin concentration in which the photoelectric conversion section (21), the transfer section (22), and the floating diffusion layer (51) are also provided. It becomes possible to reduce an interconnection capacity, a gate-drain capacity, and a gate-channel capacity, to increase gain of a source follower circuit, to relax electric fields in the vicinity of the drain (19b), and to prevent electric charges from inflow and outflow from substrate (11), without any increase in the fabrication process. As a result, a high-sensitivity, low-noise solid state imaging device can be offered.