Image-sensor structures

Patent metadata

Field	Value
Publication number	US-2016276393-A1
Application number	US-201514660284-A
Country	US
Kind code	A1
Filing date	Mar 17, 2015
Priority date	Mar 17, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

An image-sensor structure is provided. The image-sensor structure includes a substrate having a first surface and a second surface and including a sensing area, a first metal layer formed above the first surface of the substrate and surrounding the sensing area, and a protection layer formed above the first surface of the substrate and overlying the sensing area and a part of the first metal layer to expose an exposed area of the first metal layer. The exposed area includes a first portion having a first width, a second portion having a second width, a third portion having a third width and a fourth portion having a fourth width.

First claim

What is claimed is:

1 . An image-sensor structure, comprising:
a substrate having a first surface and a second surface and comprising a sensing area; a first metal layer formed above the first surface of the substrate and surrounding the sensing area; and a protection layer formed above the first surface of the substrate and overlying the sensing area and a part of the first metal layer to expose an exposed area of the first metal layer, wherein the exposed area comprises a first portion having a first width, a second portion having a second width, a third portion having a third width and a fourth portion having a fourth width.

2 . The image-sensor structure as claimed in claim 1 , wherein the first width of the first portion, the second width of the second portion, the third width of the third portion and the fourth width of the fourth portion of the exposed area of the first metal layer are respectively greater than 35 μm.

3 . The image-sensor structure as claimed in claim 1 , further comprising a second metal layer formed underneath the second surface of the substrate and surrounding the first metal layer.

4 . The image-sensor structure as claimed in claim 3 , wherein a shortest horizontal distance from the sensing area to the second metal layer is defined.

5 . The image-sensor structure as claimed in claim 4 , wherein half of the shortest horizontal distance from the sensing area to the second metal layer is greater than the first width of the first portion, the second width of the second portion, the third width of the third portion and the fourth width of the fourth portion of the exposed area of the first metal layer.

6 . The image-sensor structure as claimed in claim 1 , wherein a distance between the protection layer and a bond pad is defined.

7 . The image-sensor structure as claimed in claim 1 , further comprising color filters formed above photoelectric conversion units comprising photodiodes in the sensing area.

8 . The image-sensor structure as claimed in claim 7 , wherein the protection layer overlies a plurality of microlenses formed above the color filters.

9 . The image-sensor structure as claimed in claim 1 , wherein the protection layer comprises photoresists.

10 . The image-sensor structure as claimed in claim 1 , wherein the first portion and the third portion of the exposed area of the first metal layer are separated by the protection layer, and the second portion and the fourth portion of the exposed area of the first metal layer are separated by the protection layer.

11 . The image-sensor structure as claimed in claim 1 , wherein the first portion is connected to the second portion and the fourth portion of the exposed area of the first metal layer, and the third portion is connected to the second portion and the fourth portion of the exposed area of the first metal layer.

12 . The image-sensor structure as claimed in claim 1 , wherein the protection layer has a first side, a second side, a third side and a fourth side, which respectively correspond to the first portion, the second portion, the third portion and the fourth portion of the exposed area of the first metal layer.

13 . A method for fabricating an image-sensor structure, comprising:
providing a substrate having a first surface and a second surface and comprising a sensing area; forming a first metal layer above the first surface of the substrate and surrounding the sensing area; and forming a protection layer above the first surface of the substrate and overlying the sensing area and a part of the first metal layer.

14 . The method for fabricating an image-sensor structure as claimed in claim 13 , further comprising forming a second metal layer underneath the second surface of the substrate and surrounding the first metal layer.

15 . The method for fabricating an image-sensor structure as claimed in claim 13 , further comprising filling a photoresist layer above a plurality of pads disposed in a peripheral scribe line to a sufficient thickness.

16 . The method for fabricating an image-sensor structure as claimed in claim 15 , further comprising conformally forming a first planarization layer on the photoresist layer, the first metal layer and the first surface of the substrate.

17 . The method for fabricating an image-sensor structure as claimed in claim 16 , further comprising coating color filter patterns on the first planarization layer within the sensing area.

18 . The method for fabricating an image-sensor structure as claimed in claim 17 , further comprising forming a plurality of microlenses on a second planarization layer conformally formed on the first planarization layer and the color filter patterns, corresponding to the underneath color filter patterns.

19 . The method for fabricating an image-sensor structure as claimed in claim 18 , wherein the protection layer is formed on the second planarization layer and overlies the microlenses and a part of the first metal layer to expose a part of the first metal layer uncovered by the protection layer.

20 . The method for fabricating an image-sensor structure as claimed in claim 15 , further comprising performing an etching process to open the pads and the scribe line.

Assignees

• Visera Technologies Co Ltd

Inventors

• HUANG Chih-Kuo
• Lin Che-Sheng

Classifications

• H10F39/8063

  Microlenses · CPC title

• H10F39/8053

  Colour filters · CPC title

• H10F39/811

  Interconnections · CPC title

• H10F39/805

  Coatings · CPC title

• H10F39/804

  Containers or encapsulations · CPC title