Image sensor with embedded infrared filter layer

Patent metadata

Field	Value
Publication number	US-2016254304-A1
Application number	US-201615147888-A
Country	US
Kind code	A1
Filing date	May 5, 2016
Priority date	Sep 15, 2014
Publication date	Sep 1, 2016
Grant date	—

Abstract

An image sensor includes a substrate, photosensitive devices, a color filter layer, a micro-lens layer and an infrared filter layer. The photosensitive devices are disposed in the substrate. The color filter layer is disposed to cover the photosensitive devices. The micro-lens layer is disposed on the color filter layer. The infrared filter layer directly covers the micro-lens layer.

First claim

What is claimed is:

1 . An image sensor, comprising:
a substrate; a plurality of photosensitive devices disposed in the substrate; a color filter layer disposed to cover the photosensitive devices; a micro-lens layer disposed on the color filter layer; and an infrared filter layer directly covering the micro-lens layer, wherein a refractive index of the micro-lens layer is equal to a square root of a product of the refractive index of the infrared filter layer and a refractive index of the color filter layer.

2 . The image sensor of claim 1 , wherein the infrared filter layer has a top surface profile which is the same as a top surface profile of the micro-lens layer.

3 . The image sensor of claim 1 , wherein the infrared filter layer has a flat top surface profile.

4 . The image sensor of claim 1 , further comprising an anti-reflective coating layer disposed between the substrate and the color filter layer.

5 . The image sensor of claim 1 , wherein the infrared filter layer comprises a reflective infrared filter structure.

6 . The image sensor of claim 5 , wherein the reflective infrared filter structure is a multi-film stacked structure.

7 . The image sensor of claim 6 , wherein the multi-film stacked structure comprises a plurality of films, and the films of the multi-film stacked structure have different refractive indexes in an infrared region.

8 . An image sensor, comprising:
a substrate; a plurality of photosensitive devices disposed in the substrate; an infrared color filter structure disposed to cover the photosensitive devices, wherein the infrared color filter structure comprises a color filter layer disposed over the substrate and an infrared filter layer disposed on the color filter layer; and a micro-lens layer disposed on the infrared color filter structure, wherein a refractive index of the infrared filter layer is equal to a square root of a product of a refractive index of the color filter layer and a refractive index of the micro-lens layer.

9 . The image sensor of claim 8 , further comprising an anti-reflective coating layer disposed between the substrate and the color filter layer.

10 . The image sensor of claim 8 , wherein the infrared filter layer comprises a reflective infrared filter structure.

11 . The image sensor of claim 10 , wherein the reflective infrared filter structure is a multi-film stacked structure.

12 . The image sensor of claim 11 , wherein the multi-film stacked structure comprises a plurality of films, and the films of the multi-film stacked structure have different refractive indexes in an infrared region.

13 . A method for manufacturing an image sensor, the method comprising:
forming a plurality of photosensitive devices in a substrate; forming a color filter layer to cover the photosensitive devices; forming a micro-lens layer above the color filter layer; and forming an infrared filter layer to cover the micro-lens layer, wherein the micro-lens layer is formed to have a refractive index which is equal to a square root of a product of a refractive index of the infrared filter layer and a refractive index of the color filter layer.

14 . The method of claim 13 , wherein the infrared filter layer is formed to have a top surface profile the same as a top surface profile of the micro-lens layer.

15 . The method of claim 13 , wherein the infrared filter layer is formed to have a flat top surface profile.

16 . The method of claim 13 , before forming the color filter layer, the method further comprising forming an anti-reflective coating layer on the substrate and covering the photosensitive devices.

17 . The method of claim 13 , wherein the infrared filter layer is formed to comprise a reflective infrared filter structure.

18 . The method of claim 17 , wherein the reflective infrared filter structure is a multi-film stacked structure.

19 . The method of claim 18 , wherein the multi-film stacked structure is formed to comprise a plurality of films, and the films of the multi-film stacked structure have different refractive indexes in an infrared region.

20 . The method of claim 13 , wherein the color filter layer is formed by using a coating process.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chou Keng-Yu
• Hashimoto Kazuaki
• Liu Jen-Cheng
• Sze Jhy-Jyi
• Chiang Wei-Chieh
• Chen Pao-Tung

Classifications

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N25/00 Primary

  Circuitry of solid-state image sensors [SSIS]; Control thereof · CPC title

• H04N23/54

  Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils · CPC title

• G02B1/11

  Anti-reflection coatings · CPC title

• G02B27/1013

  for colour or multispectral image sensors, e.g. splitting an image into monochromatic image components on respective sensors (spectral imaging systems G01J) · CPC title