Light detection apparatus and method of manufacturing the same
What is provided is a light detection apparatus along with a method of manufacturing the same, the apparatus being adapted to improve both the light blocking effect between pixels and the photoelectric conversion efficiency of each pixel. The light detection apparatus of this disclosure includes a substrate, a plurality of photoelectric conversion units provided inside the substrate, and a light blocking film provided at least between the photoelectric conversion units inside the substrate. The light blocking film includes a first film provided inside the substrate and a second film provided inside the substrate via the first film. The light absorption rate of the second film is higher than that of the first film.
1 . A light detection apparatus, comprising:
a substrate;
a plurality of photoelectric conversion units provided inside the substrate; and
a light blocking film provided at least between the photoelectric conversion units inside the substrate,
wherein the light blocking film has a grid like shape in a plan view taken along a line normal to a light incident surface of the substrate,
wherein the light blocking film surrounds at least some of the photoelectric conversion units in the plan view taken along the line normal to the light incident surface of the substrate,
wherein the light blocking film includes a first film provided inside the substrate and a second film provided inside the substrate via the first film, and
wherein a light absorption rate of the second film is higher than that of the first film.
2 . The light detection apparatus according to claim 1 , wherein the first film includes a metal film.
3 . The light detection apparatus according to claim 2 , wherein the first film includes either Al (aluminum) or Cu (copper).
4 . The light detection apparatus according to claim 1 , wherein a film thickness of the first film is at least 5 nm.
5 . The light detection apparatus according to claim 1 , wherein the second film includes a metal film.
6 . The light detection apparatus according to claim 5 , wherein the second film includes W (tungsten), Ti (titanium), or Cr (chromium).
7 . The light detection apparatus according to claim 1 , wherein the second film is provided over a top surface and on a side of the first film inside the substrate.
8 . The light detection apparatus according to claim 1 , wherein the light blocking film is provided inside the substrate in a manner penetrating the substrate.
9 . The light detection apparatus according to claim 1 , wherein the light blocking film is provided inside the substrate in a manner not penetrating the substrate.
10 . The light detection apparatus according to claim 1 , wherein the light blocking film further includes a third film interposed between the first film and the second film.
11 . The light detection apparatus according to claim 10 , wherein the third film includes either an insulating film or a metal film.
12 . The light detection apparatus according to claim 1 , wherein the light blocking film further includes a fourth film and a fifth film,
the first film is provided inside the substrate via the fourth film, and
the fifth film is interposed between the first film and the second film.
13 . The light detection apparatus according to claim 12 , wherein the fourth film and the fifth film each function as a barrier metal film.
14 . The light detection apparatus according to claim 1 , wherein the substrate includes a first region that includes the plurality of photoelectric conversion units and a second region that circularly surrounds the first region, and
the light blocking film further includes a first portion interposed between the first region and the second region inside the substrate and a second portion provided over the second region outside the substrate.
15 . The light detection apparatus according to claim 14 , wherein the first portion includes the first film provided inside the substrate and the second film provided inside the substrate via the first film, and
the second portion includes the first film provided over the substrate and the second film provided over the substrate via the first film.
16 . A light detection apparatus manufacturing method, comprising:
forming a plurality of photoelectric conversion units inside a substrate; and
forming a light blocking film at least between the photoelectric conversion units inside the substrate,
wherein the light blocking film has a grid like shape in a plan view taken along a line normal to a light incident surface of the substrate,
wherein the light blocking film surrounds at least some of the photoelectric conversion units in the plan view taken along the line normal to the light incident surface of the substrate,
wherein the light blocking film is formed by forming a first film inside the substrate and by forming a second film inside the substrate via the first film, and
wherein a light absorption rate of the second film is higher than that of the first film.
17 . The light detection apparatus manufacturing method according to claim 16 , wherein the light blocking film is formed in a trench formed inside the substrate in a manner penetrating the substrate.
18 . The light detection apparatus manufacturing method according to claim 16 , wherein the light blocking film is formed in a trench formed inside the substrate in a manner not penetrating the substrate.
19 . The light detection apparatus manufacturing method according to claim 16 , wherein the light blocking film is formed by forming the first film, a third film, and the second film, in that order, inside the substrate.
20 . The light detection apparatus manufacturing method according to claim 16 , wherein the light blocking film is formed by forming a fourth film, the first film, a fifth film, and the second film, in that order, inside the substrate.