PURPOSE: To form a sufficiently deep impurity region, to inhibit the increase of photosensitibity and to augment density by shaping a deep groove around a photodiode and isolating the phototdiode from a charge transfer section and other photodiodes.

CONSTITUTION: Deep grooves 9 formed by etching and processing the surface of a substrate 1 are shaped around photodiodes 2, and the photodiodes 2 are isolated from charge transfer sections 3, and also isolated from other photodiodes and other charge transfer sections 3A. The inside of a deep groove 9b isolating the photodiode 2 from the charge transfer section 3 is filled with a conductive material such as polysilicon, thus constituting a signal reading electrode 4. Since an N-type region 5 in the photodiode 2 is isolated from others by the deep grooves 9, a diffusion in the horizontal direction is inhibited by the deep grooves 9 even when the thermal diffusion of the N-type region 5 is conducted for a prolonged time, and a diffusion is progressed only in the depth direction. Accordingly, the depth of the N-type region 5 can be increased sufficiently, and photosensitivity can be improved.