SOLID-STATE IMAGING DEVICE AND METHOD FOR MANUFACTURING THE SAME

According to one embodiment, a solid-state imaging device includes a plurality of photoelectric conversion elements, a field effect transistor, a trench, and a P-type impurity diffusion region. The plurality of photoelectric conversion elements is two-dimensionally arranged in a semiconductor layer. The field effect transistor includes N-type source and drain on a surface side of the semiconductor layer. The trench penetrates through a surface and a rear surface of the semiconductor layer and surrounds each of the photoelectric conversion elements. The width of the trench is enlarged from the surface of the semiconductor layer toward a position at a predetermined depth, and is not enlarged at a position deeper than the position at the predetermined depth. The P-type impurity diffusion region is arranged in a side surface of the trench. A P-type impurity concentration in a portion from the surface of the semiconductor layer to the position at the predetermined depth is lower than that in a portion deeper than the position at the predetermined depth.