Method of manufacturing a CCD sensor with a deep well

A method of manufacturing an interline CCD image sensor, the method comprising the steps of:

• providing a semiconductor substrate of a first conductivity type;
• ion-implanting impurities directly into the semiconductor substrate which is free of any layer at an energy of 0.7 to 16 MeV;
• heat-treating the implanted impurities for a period in which a diffusion time calculated in terms of 1100° C. is less than 10 hours so as to form a well of a second conductivity type in the semiconductor substrate;
• and
• forming an image sensing section and a vertical transfer channel in a surface of the well wherein the well is formed such that a peak of an impurity concentration is located at a deep position from the substrate surface so that a relatively lower impurity concentration region is formed on the surface thereby to reduce residual image and blooming of the image sensor.