Imaging device

Patent metadata

Field	Value
Publication number	US-2022052092-A1
Application number	US-201917250834-A
Country	US
Kind code	A1
Filing date	Sep 17, 2019
Priority date	Sep 21, 2018
Publication date	Feb 17, 2022
Grant date	—

Abstract

According to the present disclosure, there is provided an imaging device including: a first semiconductor layer ( 180 ) formed on a semiconductor substrate; a second semiconductor layer ( 170 ) formed on the first semiconductor layer ( 180 ) and having an opposite conductivity type to the first semiconductor layer ( 180 ); a pixel separation portion ( 150 ) configured to demarcate a pixel region including the first semiconductor layer ( 180 ) and the second semiconductor layer ( 170 ); a first electrode ( 130 ) connected to the first semiconductor layer ( 180 ) from one surface side of the semiconductor substrate; and a metal layer ( 152 ) connected to the second semiconductor layer ( 170 ) from a light irradiation surface side which is the other surface of the semiconductor substrate and buried in the pixel separation portion ( 150 ) in at least a part of the semiconductor substrate in a thickness direction.

First claim

1 . An imaging device comprising:
a first semiconductor layer formed on a semiconductor substrate; a second semiconductor layer formed on the first semiconductor layer and having an opposite conductivity type to the first semiconductor layer; a pixel separation portion configured to demarcate a pixel region including the first and second semiconductor layers; a first electrode connected to the first semiconductor layer from one surface side of the semiconductor substrate; and a metal layer connected to the second semiconductor layer from a light irradiation surface side which is the other surface of the semiconductor substrate and buried in the pixel separation portion in at least a part of the semiconductor substrate in a thickness direction.

2 . The imaging device according to claim 1 , further comprising:
a second electrode connected to the second semiconductor layer from the light irradiation surface side and formed to correspond to a position of the pixel separation portion, wherein the metal layer is electrically connected to the second semiconductor layer via the second electrode.

3 . The imaging device according to claim 2 , wherein the second electrode is formed along a periphery of the pixel region.

4 . The imaging device according to claim 2 , wherein the second electrode is formed in a region of a part of the periphery of the pixel region.

5 . The imaging device according to claim 4 , wherein the second electrode is formed in at least one of four corners of the rectangular pixel region.

6 . The imaging device according to claim 4 , wherein the second electrode is buried in a hole formed in the second semiconductor layer.

7 . The imaging device according to claim 4 , wherein the second electrode and the metal layer are formed of the same material.

8 . The imaging device according to claim 2 , further comprising:
an insulation film formed along the pixel separation portion and the light irradiation surface, wherein the second electrode is buried in an opening provided in the second semiconductor layer, a region in which an end of the insulation film retreats more than a wall surface of the opening is provided, and the region is filled with the second electrode.

9 . The imaging device according to claim 1 , further comprising:
an insulation film formed along the pixel separation portion, wherein a region in which an end of the insulation film retreats in a thickness direction of the pixel separation portion is formed and the region is filled with an insulation film.

10 . The imaging device according to claim 1 , wherein a voltage for multiplying electrons is applied between the first electrode and the metal layer.

11 . The imaging device according to claim 1 , further comprising a third semiconductor layer formed on the second semiconductor layer and having the same conductivity type as the second semiconductor layer.

12 . The imaging device according to claim 2 , wherein the second electrode is provided on an upper surface of the pixel separation portion.

13 . The imaging device according to claim 2 , wherein the pixel separation portion and the second electrode have a planar shape of a grid shape surrounding a plurality of the pixel regions.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Furumi Koji
• Manda Shuji
• Matsumoto Ryosuke
• Hirano Tomoyuki

Classifications

• H10F30/225

  the potential barrier working in avalanche mode, e.g. avalanche photodiodes · CPC title

• H10F39/18

  Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors · CPC title

• H10F39/811

  Interconnections · CPC title

• H10F39/807

  Pixel isolation structures · CPC title

• H10F39/802 Primary

  Geometry or disposition of elements in pixels, e.g. address-lines or gate electrodes · CPC title