FIELD: electricity.
SUBSTANCE: solid-state image sensor includes a charge accumulation region having a first conductivity type, a semiconductor insulating region formed from a semiconductor impurity region having a second conductivity type, a channel limiting region formed from a semiconductor impurity region having a second conductivity type, which is located on the semiconductor insulating region, and an insulator lying on the channel limiting region. The insulator has a first insulating area lying over the semiconductor insulating region through the channel limiting region, a second insulating area lying next to the outer surface of the first insulating area, wherein thickness of the second insulating area drops as distance from the first insulating area increases, and a third insulating area formed on the first insulating area, wherein the third insulating area has a top surface and a lateral surface, the lateral surface connecting the top surface of the third insulating area with the top surface of the second insulating area.
EFFECT: invention provides a method which is efficient in increasing the amount of charge in saturated state, weakens concentration of the electric field near the insulating element of the area and reducing etching damage on the substrate.
19 cl, 4 dwg
