Solid-state imaging device with photoelectric conversion portions in an array and manufacturing method thereof

A solid-state imaging device comprising:

• a plurality of photoelectric conversion portions each for converting incident light into signal charge the amount in charge of which corresponds to the amount of said incident light, said photoelectric conversion portions being formed within a surface region of a first conductivity type semiconductor layer and formed of a second conductivity type semiconductor layer;
• a plurality of charge readout portions provided adjacent to said photoelectric conversion portions, each of said charge readout portions being designed to read out said signal charge having been generated in the corresponding one of said photoelectric conversion portions, said charge readout portions being formed of said first conductivity type semiconductor layer;
• a plurality of charge transfer portions adjacent to said photoelectric conversion portions, each of said charge transfer portions being designed to transfer said signal charge having been retrieved from the corresponding one of said photoelectric conversion portions through the corresponding one of said charge readout portions, said charge transfer portions being formed of said second conductivity type semiconductor layer;
• a plurality of first charge transfer electrodes forming at least one layer through an insulation film over the corresponding one of said charge transfer portions, each of said first charge transfer electrodes being designed to control in transfer said signal charge of the corresponding one of said charge transfer portions;
• and
• a plurality of second charge transfer electrodes, each of which is formed, through an insulation film, over the corresponding one of said photoelectric conversion portions, the corresponding one of said charge readout portions, the corresponding one of said charge transfer portions and also over peripheral portions of these corresponding portions, is provided with an opening portion over the corresponding one of said photoelectric conversion portions, wherein adjacent ones of said second charge transfer electrodes are formed so as to be separated form each other through a separation portion separated from said opening portion, and each of said second charge transfer electrodes also is a part of a charge readout electrode for controlling the reading and writing of said signal charge from the corresponding one of said photoelectric conversion portions to the corresponding one of said charge transfer portions, said second charge transfer electrode being designed to control in transfer said signal charge of the corresponding one of said charge transfer portions.

A manufacturing method of a solid-state imaging device, said solid-state imaging device comprising:

• a plurality of photoelectric conversion portions each for converting incident light into signal charge the amount in charge of which corresponds to the amount of said incident light;
• a plurality of charge readout portions provided adjacent to said photoelectric conversion portions, each of said charge readout portions being designed to read out signal charge having been generated in the corresponding one of said photoelectric conversion portions;
• a plurality of charge transfer portions provided adjacent to said photoelectric conversion portions, each of said charge transfer portions being designed to transfer said signal charge having been retrieved from the corresponding one of said photoelectric conversion portions through the corresponding one of said charge readout portions;
• and, a charge transfer electrode, which is formed, through an insulation film, over the corresponding one of said photoelectric conversion portions, the corresponding one of said charge readout portions, the corresponding one of said charge transfer portions and also over peripheral portions of these corresponding ones, said charge transfer electrode being designed to control in transfer said signal charge of the corresponding one of said charge transfer portions;
• the method comprising:
• a first step of forming a plurality of first charge transfer electrodes each constructed of at least one layer, said first charge transfer electrodes being formed over a first conductivity type semiconductor layer, in a surface region of which are formed:
• the plurality of charge readout portions constructed of said first conductivity type semiconductor layer;
• and, said plurality of charge transfer portions constructed of said second conductivity type semiconductor layer;
• a second step of forming a photoresist film having an opening portion in a region corresponding to a region in which said plurality of photoelectric conversion portions are formed after a conductive film is formed through an insulation film;
• a third step of removing said conductive film of said region corresponding to said opening portion by using said photoresist film as a mask;
• a fourth step of forming said plurality of photoelectric conversion portions by using both said photoresist film and said conductive film as masks, or by using said conductive film only as a mask;
• and
• a fifth step of forming, by etching said conductive film, a plurality of second charge transfer electrodes, each of which is also a charge readout electrode, for controlling said reading and writing a signal charge from the corresponding one of said photoelectric conversion portions to the corresponding one of said charge transfer portions.