Solid state image sensor and its fabrication

摘要

A dipping in potential well due to direct contact between transfer electrodes and metal wiring causes a drop in transfer efficiency through a CCD register. In order to eliminate or at least reduce the potential dipping, an N--type impurity layer that functions as a CCD channel is formed with N---type impurity regions that have impurity concentration lower than that of the N--type impurity layer. The N--type impurity regions are located below transfer electrodes in alignment with contact apertures.