Solid state image sensor with plural overlapping photoelectric conversion units

• US 9,337,231 B2
• Filed: 08/06/2010
• Issued: 05/10/2016
• Est. Priority Date: 08/08/2009
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Narui, Tadashi
• Primary Examiner(s): BUI PHO, PASCAL M
• Application Number:
  US12/852,155
• Publication Number:
  US 20110068251A1
• Time in Patent Office: 2,104 Days
• Field of Search: 250/208.1, 250/214.R, 250/214.1, 250/226, 250/214.A, 250/216, 348/266, 348/268, 348270-283, 348300-302, 348/336, 257/414, 257/431, 257/432, 257/434, 257/440, 257/443, 356/402, 356/416, 356/419
• US Class Current: 1/1
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14641 Electronic components shared by two or more pixel-elements, e.g. one amplifier shared by two pixel elements
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements

Abstract

A solid-state image sensor includes: four or more photoelectric conversion units having spectral sensitivity characteristics different from one another; an amplifier unit disposed in correspondence to each group of photoelectric conversion units among N groups (N represents an integer less than a quantity of the four or more photoelectric conversion units and equal to or greater than one), the four or more photoelectric conversion units being divided into the N groups; and transfer units, each disposed in correspondence to one of the four or more photoelectric conversion units, which transfer a signal generated at the photoelectric conversion unit to the amplifier unit disposed for the group to which the photoelectric conversion unit belongs.

Claims

1. A solid-state image sensor, comprising:

four or more photoelectric conversion units having spectral sensitivity characteristics different from one another, at least two of the photoelectric conversion units disposed at different depths in a substrate, the at least two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

color filters having spectral transmittance characteristics different from one another, each of which is in correspondence to one of N (N represents an integer less than a quantity of the four or more photoelectric conversion units and equal to or greater than three) groups of photoelectric conversion units, a plurality of photoelectric conversion units among the four or more photoelectric conversion units belonging to each of the N groups, wherein;

the color filters are disposed on a light-entry side of the plurality of photoelectric conversion units belonging to each specific group;

charge storage layers each constituting one of the plurality of photoelectric conversion units belonging to the specific group are disposed in alignment with one another along a direction in which light enters;

the quantity of the four or more photoelectric conversion units is six, N is equal to three and a quantity of photoelectric conversion units belonging to each group is two;

the three groups each include a first photoelectric conversion unit with a charge storage layer thereof disposed on a light-entry side and a second photoelectric conversion unit with a charge storage layer thereof disposed on a side opposite from the light-entry side;

the three first photoelectric conversion units in the three groups are formed so as to satisfy a first condition and the three second photoelectric conversion units in the three groups are formed so as to satisfy a second condition; and

the first condition stipulates that the charge storage layers each constituting one of the three first photoelectric conversion units assume positions with a uniform depth measured from a semiconductor surface on the light-entry side and the second condition stipulates that the charge storage layers each constituting one of the three second photoelectric conversion units assume positions with a uniform depth measured from the semiconductor surface on the light-entry side.

2. A solid-state image sensor comprising:

four or more photoelectric conversion units having spectral sensitivity characteristics different from one another, at least two of the photoelectric conversion units disposed at different depths in a substrate, the at least two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate;

an amplifier unit disposed in correspondence to each group of photoelectric conversion units among N groups (N represents an integer less than a quantity of the four or more photoelectric conversion units and equal to or greater than one), the four or more photoelectric conversion units being divided into the N groups; and

transfer units, each disposed in correspondence to one of the four or more photoelectric conversion units, which transfer a signal generated at the photoelectric conversion unit to the amplifier unit disposed for the group to which the photoelectric conversion unit belongs, wherein;

the quantity of the four or more photoelectric conversion units is six, N is equal to three and a quantity of photoelectric conversion units belonging to each group is two;

the three groups each include a first photoelectric conversion unit with a charge storage layer thereof disposed on a light-entry side and a second photoelectric conversion unit with a charge storage layer thereof disposed on a side opposite from the light-entry side;

the three first photoelectric conversion units in the three groups are formed so as to satisfy a first condition and the three second photoelectric conversion units in the three groups are formed so as to satisfy a second condition; and

the first condition stipulates that the charge storage layers each constituting one of the three first photoelectric conversion units assume positions with a uniform depth measured from a semiconductor surface on the light-entry side and the second condition stipulates that the charge storage layers each constituting one of the three second photoelectric conversion units assume positions with a uniform depth measured from the semiconductor surface on the light-entry side.

3. A solid-state image sensor comprising:

four or more photoelectric conversion units having spectral sensitivity characteristics different from one another, at least two of the photoelectric conversion units disposed at different depths in a substrate, the at least two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate;

an amplifier unit disposed in correspondence to each group of photoelectric conversion units among N groups (N represents an integer less than a quantity of the four or more photoelectric conversion units and equal to or greater than one), the four or more photoelectric conversion units being divided into the N groups; and

transfer units, each disposed in correspondence to one of the four or more photoelectric conversion units, which transfer a signal generated at the photoelectric conversion unit to the amplifier unit disposed for the group to which the photoelectric conversion unit belongs, wherein;

the quantity of the four or more photoelectric conversion units is six, N is equal to three and a quantity of photoelectric conversion units belonging to each group is two;

the three groups each include a first photoelectric conversion unit with a charge storage layer thereof disposed on a light-entry side and a second photoelectric conversion unit with a charge storage layer thereof disposed on a side opposite from the light-entry side;

the three first photoelectric conversion units in the three groups and the three second photoelectric conversion units in the three groups are formed so that at least one of a first condition and a second condition is not satisfied; and

the first condition stipulates that the charge storage layers each constituting one of the three first photoelectric conversion units assume positions with a uniform depth measured from a semiconductor surface on the light-entry side and the second condition stipulates that the charge storage layers each constituting one of the three second photoelectric conversion units assume positions with a uniform depth measured from the semiconductor surface on the light-entry side.

4. A solid-state image sensor comprising:

four or more photoelectric conversion units having spectral sensitivity characteristics different from one another, at least two of the photoelectric conversion units disposed at different depths in a substrate, the at least two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

color filters having spectral transmittance characteristics different from one another, each of which is in correspondence to one of N (N represents an integer less than a quantity of the four or more photoelectric conversion units and equal to or greater than three) groups of photoelectric conversion units, a plurality of photoelectric conversion units among the four or more photoelectric conversion units belonging to each of the N groups, wherein;

the color filters are disposed on a light-entry side of the plurality of photoelectric conversion units belonging to each specific group;

charge storage layers each constituting one of the plurality of photoelectric conversion units belonging to the specific group are disposed in alignment with one another along a direction in which light enters;

the quantity of the four or more photoelectric conversion units is six, N is equal to three and a quantity of photoelectric conversion units belonging to each group is two;

the three groups each include a first photoelectric conversion unit with a charge storage layer thereof disposed on a light-entry side and a second photoelectric conversion unit with a charge storage layer thereof disposed on a side opposite from the light-entry side;

the three first photoelectric conversion units in the three groups and the three second photoelectric conversion units in the three groups are formed so that at least one of a first condition and a second condition is not satisfied; and

the first condition stipulates that the charge storage layers each constituting one of the three first photoelectric conversion units assume positions with a uniform depth measured from a semiconductor surface on the light-entry side and the second condition stipulates that the charge storage layers each constituting one of the three second photoelectric conversion units assume positions with a uniform depth measured from the semiconductor surface on the light-entry side.

5. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate;

an amplifier unit disposed in correspondence to each of the pixels; and

a control unit that selects an operation at the photoelectric conversion units in a first operation mode or a second operation mode;

wherein;

in the first operation mode, a first signal generated in one of the photoelectric conversion unit disposed at a single pixel and a second signal generated in another photoelectric conversion unit disposed at the single pixel are separately output from the amplifier unit; and

in the second operation mode, a third signal corresponding to a sum of the first signal and the second signal is output from the amplifier unit.

6. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate;

an amplifier unit disposed in correspondence to of the pixels; and

a control unit that selects an operation at the photoelectric conversion units in a first operation mode or a second operation mode;

wherein

in the first operation mode, a first signal generated in one of the photoelectric conversion unit disposed at a single pixel and a second signal generated in another photoelectric conversion unit disposed at the single pixel are separately output from the amplifier unit; and

in the second operation mode, the first signal or the second signal is output from the amplifier unit and a third signal corresponding to a sum of the first signal and the second signal is output from the amplifier unit.

7. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

an amplifier unit disposed in correspondence to of the pixels, wherein;

three first photoelectric conversion units disposed at a light-entry side of the substrates in the three pixels are formed so as to satisfy a first condition and three second photoelectric conversion units disposed at an opposite side of the substrates in the three pixels are formed so as to satisfy a second condition; and

the first condition stipulates that the three first photoelectric conversion units are disposed at positions with a uniform depth and the second condition stipulates that the three second photoelectric conversion units are disposed at positions with a uniform depth.

8. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

an amplifier unit disposed in correspondence to of the pixels, wherein;

three first photoelectric conversion units disposed at a light-entry side of the substrates in the three pixels and three second photoelectric conversion units disposed at an opposite side of the substrates in the three pixels are formed so that at least one of a first condition and a second condition is not satisfied; and

the first condition stipulates that the three first photoelectric conversion units are disposed at positions with a uniform depth and the second condition stipulates that the three second photoelectric conversion units are disposed at positions with a uniform depth.

9. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

color filters disposed on a light-entry side of the plurality of photoelectric conversion units belonging to each pixel, wherein;

each of three color filters disposed in correspondence to each of three pixels have spectral transmittance characteristics different from one another;

three first photoelectric conversion units disposed at the light-entry side of the substrates in the three pixels are formed so as to satisfy a first condition and three) second photoelectric conversion units disposed at an opposite side of the substrates in the three pixels are formed so as to satisfy a second condition; and

the first condition stipulates that the three first photoelectric conversion units are disposed at positions with a uniform depth and the second condition stipulates that the three second photoelectric conversion units are disposed at positions with a uniform depth.

10. A solid-state image sensor having a plurality of pixels in three pixels having at least three distinct characteristics different from one another, the solid-state image sensor comprising:

two photoelectric conversion units disposed at each of the three pixels and that perform photoelectric conversion of light having spectral characteristics that are different from each other, the two photoelectric conversion units each disposed at a different depth in a substrate, the two photoelectric conversion units at least partially overlapping in a direction perpendicular to a surface of the substrate; and

color filters disposed on a light-entry side of the plurality of photoelectric conversion units belonging to each pixel, wherein;

each of three color filters disposed in correspondence to each of three pixels have spectral transmittance characteristics different from one another;

three first photoelectric conversion units disposed at the light-entry side of the substrates in the three pixels and the three second photoelectric conversion units disposed at an opposite side of the substrates in the three pixels are formed so that at least one of a first condition and a second condition is not satisfied; and

the first condition stipulates that the three first photoelectric conversion units are disposed at positions with a uniform depth and the second condition stipulates that the three second photoelectric conversion units are disposed at positions with a uniform depth.