Solid-state image capturing element to suppress dark current, manufacturing method thereof, and electronic device

A method of manufacturing a solid-state image capturing element, the method comprising:

• forming a photoelectric conversion unit on a semiconductor substrate, wherein
• the semiconductor substrate comprises a first insulation film and a semiconductor layer on the first insulation film, and
• the semiconductor layer includes a semiconductor region;
• forming a charge retention section in the semiconductor layer, wherein
• a bottom surface of the charge retention section is in contact with the first insulation film,
• the bottom surface of the charge retention section is opposite to a surface of a gate side of a reset transistor, and
• the reset transistor is in the semiconductor substrate;
• forming a second insulation film adjacent to a first side surface of the charge retention section;
• forming a third insulation film on a top surface of the charge retention section, wherein
• the second insulation film is in contact with each of the third insulation film and the first insulation film,
• each of a second side surface of the charge retention section and a third side surface of the charge retention section is in contact with the third insulation film,
• a fourth side surface of the charge retention section is under the surface of the gate side of the reset transistor,
• the first side surface of the charge retention section is opposite to the fourth side surface of the charge retention section, and
• the fourth side surface of the charge retention section is in contact with the semiconductor region of the semiconductor layer;
• forming a connection conductor above the first side surface of the charge retention section and the second insulation film;
• forming a contact electrode on the connection conductor, wherein the connection conductor is in contact with the charge retention section, the second insulation film, and the contact electrode;
• and
• forming a color filter at a light incident side of the photoelectric conversion unit.

An electronic device, comprising:

• a solid-state image capturing element comprising:
• a semiconductor substrate that comprises a first insulation film and a semiconductor region;
• a reset transistor in the semiconductor substrate;
• a photoelectric conversion unit on the semiconductor substrate, wherein the photoelectric conversion unit is configured to generate charges;
• a charge retention section in the semiconductor substrate, wherein
• the charge retention section is configured to retain the generated charges,
• a bottom surface of the charge retention section is in contact with the first insulation film, and
• the bottom surface of the charge retention section is opposite to a surface of a gate side of the reset transistor;
• a second insulation film adjacent to a first side surface of the charge retention section;
• a third insulation film on a top surface of the charge retention section, wherein
• the second insulation film is in contact with each of the third insulation film and the first insulation film,
• each of a second side surface of the charge retention section and a third side surface of the charge retention section is in contact with the third insulation film,
• a fourth side surface of the charge retention section is under the surface of the gate side of the reset transistor,
• the first side surface of the charge retention section is opposite to the fourth side surface of the charge retention section, and
• the fourth side surface of the charge retention section is in contact with the semiconductor region of the semiconductor substrate;
• a connection conductor above the first side surface of the charge retention section and the second insulation film;
• a contact electrode on the connection conductor, wherein the connection conductor is in contact with the charge retention section, the second insulation film, and the contact electrode;
• and
• a color filter at a light incident side of the photoelectric conversion unit.