Patent ID: 7679668

Claim:
A solid state image pickup device comprising: a plurality of photoelectric conversion elements, disposed in a semiconductor substrate in a matrix shape, for photoelectrically converting incidence light into signal charge; a plurality of vertical transfer channels each disposed in said semiconductor substrate adjacent to each column of said photoelectric conversion elements; a read gate, formed between a photoelectric conversion element in said plurality of photoelectric conversion elements and a vertical transfer channel in said plurality of vertical transfer channels, for controlling read signal charge generated in said photoelectric conversion element to said vertical transfer channel; an insulating film including a silicon oxide film formed on said semiconductor substrate and covering said photoelectric conversion elements, said read gate and said vertical transfer channel, and a silicon nitride film covering said vertical transfer channel via said silicon oxide film, extending above a surface of said read gate, and having a tapered side wall; a plurality of vertical transfer electrodes having a plurality of layers alternately formed along a column direction and formed above said insulating film, said plurality of vertical transfer electrodes reading signal charge generated in each of said photoelectric conversion elements to a corresponding one of said vertical transfer channels by controlling a potential of said read gate, and transferring the signal charge read to said vertical transfer channel along the column direction by controlling a potential of said vertical transfer channel; and a horizontal CCD for transferring signal charge transferred from said vertical transfer channels along a row direction, wherein said side wall of said silicon nitride film comprises a lower portion and an upper portion having a slope which is greater than a slope of said lower portion.