Image sensor device with insulation film

Abstract

A charge-coupled device (CCD) is provides having improved charge transfer efficiency. This CCD is a portion of an image sensor and manufactured by first laminating a first oxidation film and a first nitride film one after the other on a semiconductor substrate and then forming a plurality of first gate electrodes on the first nitride film at predetermined intervals apart. A second oxidation film is formed only on an upper surface and along side walls of each of the first gate electrodes. The first nitride film exposed between the first gate electrodes is removed and a second nitride film is formed on the exposed first oxidation film and the second oxidation film. A second gate electrode is then formed on the second nitride film between adjacent first gate electrodes. An image sensor is obtained in which leakage current density between the gate electrodes is reduced and the dielectric characteristic of a gate dielectric film is improved.

Dependencies are inferred from the claim text.