Imaging device and imaging apparatus

1 . An imaging device, comprising:

a pixel including a first photoelectric conversion unit and a second photoelectric conversion unit, wherein

the first photoelectric conversion unit is adjacent to a first surface of a semiconductor substrate,

the first photoelectric conversion unit is configured to:

perform photoelectric conversion of incident light;

generate a first charge based on the photoelectric conversion of the incident light; and

transmit the incident light to the second photoelectric conversion unit,

the second photoelectric conversion unit is in the semiconductor substrate, and

the second photoelectric conversion unit is configured to:

perform photoelectric conversion of the incident light transmitted by the first photoelectric conversion unit; and

generate a second charge based on the photoelectric conversion of the incident light;

a pixel circuit on a second surface of the semiconductor substrate, wherein

the second surface of the semiconductor substrate is different from the first surface of the semiconductor substrate, and

the pixel circuit is configured to generate an image signal based on each of the generated first charge and the generated second charge;

a light-shielding wall at a boundary of the pixel in the semiconductor substrate, wherein

the light-shielding wall is configured to shield the incident light, and

the light-shielding wall comprises a metal;

a first insulating film between the light-shielding wall and the semiconductor substrate;

a through electrode on the light-shielding wall, wherein

the through electrode is configured to transmit each of the generated first charge and the generated second charge to the pixel circuit, and

the through electrode penetrates the semiconductor substrate;

a second insulating film between the light-shielding wall and the through electrode; and

a protrusion at an end of the light-shielding wall.

2 . The imaging device according to claim 1 , wherein

the protrusion is at the end on a side adjacent to the first photoelectric conversion unit, and

the protrusion protrudes in a direction from the first surface of the semiconductor substrate toward the first photoelectric conversion unit.

3 . The imaging device according to claim 2 , wherein a protrusion length of the protrusion from the first surface of the semiconductor substrate is 5 μm or less.

4 . The imaging device according to claim 2 , further comprising a color filter between the first photoelectric conversion unit and the semiconductor substrate in the pixel, wherein the protrusion surrounds the color filter.

5 . The imaging device according to claim 1 , wherein the through electrode is in a through hole that is in the light-shielding wall.

6 . The imaging device according to claim 5 , wherein

the protrusion is adjacent to an opening of the through hole on a side different from a side adjacent to the first photoelectric conversion unit, and

the protrusion protrudes in a direction toward the through electrode.

7 . The imaging device according to claim 5 , wherein the light-shielding wall has a tapered cross section of a region adjacent to the through hole.

8 . The imaging device according to claim 5 , further comprising a light-shielding film in vicinity to the through hole on a side adjacent to the first photoelectric conversion unit.

9 . An imaging apparatus, comprising:

a pixel including a first photoelectric conversion unit and a second photoelectric conversion unit, wherein

the first photoelectric conversion unit is adjacent to a first surface of a semiconductor substrate,

the first photoelectric conversion unit is configured to:

perform photoelectric conversion of incident light;

generate a first charge based on the photoelectric conversion of the incident light; and

transmit the incident light to the second photoelectric conversion unit,

the second photoelectric conversion unit is in the semiconductor substrate, and

the second photoelectric conversion unit is configured to:

perform photoelectric conversion of the incident light transmitted by the first photoelectric conversion unit; and

generate a second charge based on the photoelectric conversion of the incident light;

a pixel circuit on a second surface of the semiconductor substrate, wherein

the second surface of the semiconductor substrate is different from the first surface of the semiconductor substrate, and

the pixel circuit is configured to generate an image signal based on each of the generated first charge and the generated second charge;

a light-shielding wall at a boundary of the pixel in the semiconductor substrate, wherein

the light-shielding wall is configured to shield the incident light, and

the light-shielding wall comprises a metal;

a first insulating film between the light-shielding wall and the semiconductor substrate;

a through electrode on the light-shielding wall, wherein

the through electrode is configured to transmit each of the generated first charge and the generated second charge to the pixel circuit, and

the through electrode penetrates the semiconductor substrate;

a second insulating film between the light-shielding wall and the through electrode;

a protrusion at an end of the light-shielding wall; and

a processing circuit configured to process the generated image signal.