# US 8,541,857 B2 · Backside illumination CMOS image sensors and methods of manufacturing the same

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- Number: US 8,541,857 B2
- Document ID: US8541857B2
- Status: Granted
- Kind: B2
- Application number: 12/984,404
- Filed: 2011-01-04
- Published: 2011-08-11
- Granted: 2013-09-24
- Earliest claimed: 2010-02-05
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Jung-chak Ahn; Kyung-ho Lee
- Inventors: Jung-chak Ahn; Kyung-ho Lee
- Web page: https://patentgrep.com/patent/US8541857B2

## CPC

- H10F 39/199: {Back-illuminated image sensors}
- H10F 39/014: {of CMOS image sensors}
- H10F 39/182: {Colour image sensors}
- H10F 39/8033: {Photosensitive area}
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

Backside illumination CMOS image sensors having convex light-receiving faces and methods of manufacturing the same. A backside illumination CMOS image sensor includes a metal layer, an insulating layer and a photodiode. The insulating layer is on the metal layer. The photodiode is on the insulating layer, and a top face of the photodiode, which receives light, is curved. A method of manufacturing a backside illumination CMOS image sensor including a photodiode having a convex surface includes forming an island smaller than the photodiode on a portion of a light-receiving face of the photodiode, and annealing the island to form the photodiode having the convex light-receiving face.

## Claims

### Claim 1

A backside illumination CMOS image sensor, comprising:
a conductive layer;
an insulating layer on the conductive layer;
a photodiode with at least one curved surface on the insulating layer, the at least one curved surface of the photodiode having a curvature such that light incident to an outer portion of the photodiode is focused to a center portion of the photodiode;
a color filter on the photodiode, a surface of the color filter farthest from the photodiode being curved; and
a micro-lens on the color filter.

### Claim 2 (depends on 1)

The backside illumination CMOS image sensor of claim 1, wherein the at least one curved surface of the photodiode is a convex surface, and
the photodiode is configured to receive light through the convex surface.

### Claim 3 (depends on 1)

The backside illumination CMOS image sensor of claim 1, wherein a curvature of the surface of the color filter corresponds to the curvature of the at least one curved surface of the photodiode.

### Claim 4 (depends on 1)

The backside illumination CMOS image sensor of claim 1, further comprising:
a planarization layer between the color filter and the micro-lens.

### Claim 5

A backside illumination CMOS image sensor, comprising:
a plurality of metal layers;
at least one inter-metal dielectric between the plurality of metal layers;
an interlayer dielectric on the plurality of metal layers;
a photodiode with a convex surface on the interlayer dielectric, the convex surface on an opposite side of the photodiode from the interlayer dielectric, the at least one curved surface of the photodiode having a curvature such that light incident to an outer portion of the photodiode is focused to a center portion of the photodiode;
a color filter on the photodiode, a surface of the color filter farthest from the photodiode being curved; and
a micro-lens on the color filter.

### Claim 6 (depends on 5)

The backside illumination CMOS image sensor of claim 5, further comprising:
a planarization layer between the color filter and the micro-lens.

### Claim 7 (depends on 5)

A method of manufacturing the backside illumination CMOS image sensor of claim 5, the method comprising:
forming an island smaller than the photodiode on the opposite side of the photodiode; and
annealing the island to form the photodiode with the convex surface.

### Claim 8 (depends on 5)

The backside illumination CMOS image sensor of claim 5, wherein a curvature of the surface of the color filter corresponds to the curvature of the at least one curved surface of the photodiode.