Imaging element and method of manufacturing the same, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-2018240847-A1
Application number	US-201615554630-A
Country	US
Kind code	A1
Filing date	Feb 25, 2016
Priority date	Mar 9, 2015
Publication date	Aug 23, 2018
Grant date	—

Abstract

The present technology relates to a back surface irradiation type imaging element having an organic photoelectric conversion film capable of preventing color mixing and securing dynamic range, a method of manufacturing the same, and an electronic apparatus. An imaging element according to an aspect of the present technology includes a photoelectric conversion film provided on one side of a semiconductor substrate, a pixel separation section formed in an inter-pixel region, and a through electrode that transmits a signal, corresponding to an electric charge obtained by photoelectric conversion in the photoelectric conversion film, to a wiring layer formed on the other side of the semiconductor substrate, the through electrode being formed in the inter-pixel region. The present technology is applicable to a back surface irradiation type CMOS image sensor.

First claim

1 . An imaging element comprising:
pixels, the pixels each having
a photoelectric conversion film provided on one side of a semiconductor substrate,
a pixel separation section formed in an inter-pixel region, and
a through electrode that transmits a signal, corresponding to an electric charge obtained by photoelectric conversion in the photoelectric conversion film, to a wiring layer formed on another side of the semiconductor substrate, the through electrode being formed in the inter-pixel region.

2 . The imaging element according to claim 1 , wherein the pixel separation section and the through electrode are formed in such a manner that an insulating film of the pixel separation section and an insulating film covering a periphery of the through electrode make contact with each other.

3 . The imaging element according to claim 1 , wherein the through electrode is connected to a reading-out element in the wiring layer through a polysilicon electrode formed on an element separation section formed in the semiconductor substrate.

4 . The imaging element according to claim 3 , wherein a silicide is provided at an upper portion of the polysilicon electrode.

5 . The imaging element according to claim 3 , wherein a high-dielectric-constant gate insulating film is provided between the through electrode and the polysilicon electrode.

6 . The imaging element according to claim 3 , wherein the through electrode is formed by embedding, in a through-hole, an impurity-doped polysilicon which is a material for the polysilicon electrode, at the time of forming the polysilicon electrode.

7 . The imaging element according to claim 6 , wherein the pixel separation section is formed in such a manner that an insulating film of the pixel separation section and an insulating film covering a periphery of the through electrode make contact with each other, at the time of processing on the one side.

8 . The imaging element according to claim 6 , wherein the through electrode formed from the impurity-doped polysilicon is connected to an electrode of the photoelectric conversion film through an electrode plug, and a high-dielectric-constant gate insulating film is provided between the through electrode and the electrode plug.

9 . The imaging element according to claim 1 , further comprising:
a light-shielding film that covers part of a light receiving region of the pixel which is a phase difference detection pixel, wherein an upper end portion of the through electrode is formed in such a manner as to cover a range including an upper side of an insulating film covering a periphery of the through electrode.

10 . The imaging element according to claim 1 , wherein a metal is used as a material constituting that part of the pixel separation section which does not make contact with an insulating film covering a periphery of the through electrode.

11 . The imaging element according to claim 1 , further comprising:
a light-shielding film formed on the pixel separation section, wherein an upper end portion of the through electrode is formed to cover an upper side of an insulating film covering a periphery of the through electrode and to be separate from the light-shielding film.

12 . The imaging element according to claim 1 , wherein a plurality of the through electrodes are formed in the inter-pixel region between two adjacent ones of the pixels.

13 . A method of manufacturing an imaging element, the method comprising:
a front surface step of forming a configuration including a wiring layer on a semiconductor substrate; and a back surface step of the semiconductor substrate, the back surface step including the steps of
forming a groove for forming a pixel separation section in an inter-pixel region, and a through-hole for forming in the inter-pixel region a through electrode that transmits a signal, corresponding to an electric charge obtained by photoelectric conversion in a photoelectric conversion film, to the wiring layer,
forming the pixel separation section in the groove,
forming the through electrode in the through-hole, and
forming the photoelectric conversion film.

14 . The method of manufacturing according to claim 13 , wherein the groove and the through-hole are formed in a same step.

15 . The method of manufacturing according to claim 13 , wherein the groove and the through-hole are formed in different steps.

16 . An electronic apparatus comprising:
an optical section including a lens; an imaging element that receives light incident thereon through the optical section, the imaging element including pixels, the pixels each having
a photoelectric conversion film provided on one side of a semiconductor substrate,
a pixel separation section formed in an inter-pixel region, and
a through electrode that transmits a signal, corresponding to an electric charge obtained by photoelectric conversion in the photoelectric conversion film, to a wiring layer formed on another side of the semiconductor substrate, the through electrode being formed in the inter-pixel region; and
a signal processing section that processes pixel data outputted from the imaging element.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Ota Kazunobu
• Sato Mitsuru
• Wakano Toshifumi

Classifications

• H10W20/023

  the interconnections being through-semiconductor vias · CPC title

• H10W20/20

  Interconnections within wafers or substrates, e.g. through-silicon vias [TSV] · CPC title

• H10W20/0234

  comprising etching via holes that stop on pads or on electrodes · CPC title

• H10W20/0242

  comprising etching via holes from the back sides of the chips, wafers or substrates · CPC title

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title