Solid-state imaging device and manufacturing method

Patent metadata

Field	Value
Publication number	US-11387264-B2
Application number	US-201716349341-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 21, 2016
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A substrate includes a photoelectric converting unit in a pixel unit and a reflection ratio adjusting layer provided on the substrate in an incident direction of incident light with respect to the substrate for adjusting reflection of the incident light on the substrate. The reflection ratio adjusting layer includes a first layer formed on the substrate and a second layer formed on the first layer, the first layer has an uneven structure provided on the substrate, and a recess portion on the uneven structure is filled with a material having a lower refractive index than that of the substrate forming the second layer, and a thickness of the first layer is optimized for a wavelength of light to be received. The present technology may be applied to an imaging device.

First claim

What is claimed is:

1. A solid-state imaging device, comprising:
a substrate including a photoelectric converting unit in a pixel unit; and
a reflection ratio adjusting layer provided on the substrate in an incident direction of incident light with respect to the substrate for adjusting reflection of the incident light on the substrate,
wherein the reflection ratio adjusting layer includes:
a first layer formed on the substrate and a second layer formed on the first layer,
the first layer has an uneven structure including projected portions and recess portions provided on the substrate, and the recess portions of the uneven structure are filled with a material having a lower refractive index than a refractive index of the second layer, and
a thickness of the first layer is made to a thickness optimized for a wavelength of light to be received,
wherein the projected portions and the substrate including the photoelectric converting unit are made of a same material,
wherein the recess portions and the projected portions have a rectangular shape, and
wherein a width of the rectangular shaped recess portions is greater than a width of the rectangular shaped projected portions in a cross-sectional view.

2. The solid-state imaging device according to claim 1 ,
wherein a space occupancy of the first layer is a space occupancy optimized for the wavelength of the light to be received.

3. The solid-state imaging device according to claim 1 ,
wherein the thickness of the first layer is set for each pixel and is made a thickness satisfying the equation:

⁢

H
=

λ
0

4
⁢

n
eff

when the thickness of the first layer is H, a refractive index of the first layer is neff, and the wavelength of the light to be received is λ.

4. The solid-state imaging device according to claim 3 ,
wherein an effective refractive index neff of the first layer satisfies the equation:
n eff =√{square root over ( n 1 n 2 )}

when a refractive index of the second layer is n 1 and a refractive index of the substrate is n 2 .

5. The solid-state imaging device according to claim 1 ,
wherein the thickness of the first layer is set for each pixel and is a thickness satisfying the equation:

H
=

∫

λ

m
⁢

⁢
i
⁢

⁢
n

λ

ma
⁢

⁢
x

⁢

w
⁡

(
λ
)

⁢
λ

n
eff

⁡

(
λ
)

⁢
d
⁢

⁢
λ

4
⁢

∫

λ

m
⁢

⁢
i
⁢

⁢
n

λ

ma
⁢

⁢
x

⁢

w
⁡

(
λ
)

⁢
d
⁢

⁢
λ

when the thickness of the first layer is H, the wavelength of the light to be received is λ, a refractive index of the first layer is neff(λ), a spectral sensitivity is w(λ), a maximum value of the wavelength of the light to be received is λmax, and a minimum value of the wavelength of the light to be received is λmin.

6. The solid-state imaging device according to claim 1 ,
wherein the thickness of the first layer is set for each pixel and is a thickness satisfying the equation:

H
=

λ
p

4
⁢

n
eff

⁡

(

λ
p

)

when the thickness of the first layer is H, a peak value of a spectral sensitivity of the wavelength of the light to be received is λp, and the refractive index of the first layer is neff(λ).

7. The solid-state imaging device according to claim 1 ,
wherein the thickness of the first layer is set for each pixel

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Takeuchi Koichi

Classifications

• H10P76/00

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title

• G02B1/115

  Multilayers · CPC title

• H10F39/8067

  Reflectors · CPC title