# US 10,312,279 B2 · High dynamic range pixel with in-pixel light shield structures

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,312,279 B2
- Document ID: US10312279B2
- Status: Granted
- Kind: B2
- Application number: 15/799,833
- Filed: 2017-10-31
- Published: 2019-05-02
- Granted: 2019-06-04
- Earliest claimed: 2017-10-31
- Assignees: Semiconductor Components Industries, LLC
- Applicants: Semiconductor Components Industries, LLC
- Inventors: Swarnal Borthakur; Marc Allen Sulfridge
- Web page: https://patentgrep.com/patent/US10312279B2

## CPC

- H10F 39/8057: {Optical shielding}
- H10F 39/024: {of coatings or optical elements}
- H10F 39/182: {Colour image sensors}
- H10F 39/8023: {Disposition of the elements in pixels, e.g. smaller elements in the centre of the imager compared to larger elements at the periphery}
- H10F 39/8027: {Geometry of the photosensitive area}
- H10F 39/8063: {Microlenses}
- H10F 39/807: {Pixel isolation structures}
- H10F 39/813: {Electronic components shared by multiple pixels, e.g. one amplifier shared by two pixels}
- H10F 39/8053: {Colour filters}
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

Multi-photodiode image pixels may include sub-pixels with differing light sensitivities. Microlenses may be formed over the multi-photodiode image pixels so that light sensitivity of sub-pixels in an outer group of sub-pixels is enhanced. To prevent high angle light incident upon one of the sub-pixels of the image pixel from generating charges in a photosensitive region of another sub-pixel of the image pixel, intra-pixel isolation structures may be formed. Intra-pixel isolation structures may surround, and in some embodiments, overlap the light collecting region of an inner photodiode. When the intra-pixel isolation structures have a different index of refraction than light filtering material formed adjacent to the isolation structures, high angle light incident upon the isolation structures may be reflected back into the sub-pixel it was initially incident upon. Intra-pixel isolation structures may be formed entirely from optically transparent materials or a combination of optically transparent and opaque materials.

## Claims

### Claim 1

An image pixel, comprising:
an outer sub-pixel group that includes at least a first sub-pixel, wherein the first sub-pixel has a first light sensitivity;
an inner sub-pixel group that is nested within the outer sub-pixel group and that includes at least a second sub-pixel, wherein the second sub-pixel has a second light sensitivity that is less than the first light sensitivity;
a light filter layer formed over at least the outer sub-pixel group;
an inter-pixel light shielding structure that is formed at an outer boundary of the image pixel; and
an intra-pixel light shielding structure that is formed over an outer perimeter of the inner sub-pixel group, wherein the light filter layer, the inter-pixel light shielding structure, and the intra-pixel light shielding structure are coplanar.

### Claim 2 (depends on 1)

The image pixel of claim 1, wherein the light filter layer is formed only between the inter-pixel light shielding structure and the intra-pixel light shielding structure.

### Claim 3 (depends on 2)

The image pixel of claim 2, wherein the intra-pixel light shielding structure completely covers the second sub-pixel.

### Claim 4 (depends on 3)

The image pixel of claim 3, wherein the light filter layer is a clear filter.

### Claim 5 (depends on 1)

The image pixel of claim 1, wherein the light filter layer has a first portion formed over the inner sub-pixel group and a second portion formed over the outer sub-pixel group, wherein the intra-pixel light shielding structure extends in a ring around the first portion, wherein the inter-pixel light shielding structure extends in a ring around the second portion, and wherein the second portion is interposed between the intra-pixel light shielding structure and the inter-pixel light shielding structure.

### Claim 6 (depends on 5)

The image pixel of claim 5, wherein the light filter layer is a color filter.

### Claim 7 (depends on 5)

The image pixel of claim 5, wherein the light filter layer is a color filter and wherein the first and second portions both transmit the same color of light.

### Claim 8 (depends on 1)

The image pixel of claim 1, wherein the intra-pixel light shielding structure has an optically transparent portion having a first index of refraction and wherein the light filter layer has a second index of refraction that is different from the first index of refraction.

### Claim 9 (depends on 1)

The image pixel of claim 1, wherein the intra-pixel light shielding structure comprises:
an optically opaque portion that is formed over the outer perimeter of the inner sub-pixel group; and
an optically transparent portion that is formed over the optically opaque portion.

### Claim 10 (depends on 1)

The image pixel of claim 1, further comprising:
microlenses that direct incident light toward the second sub-pixel group.

### Claim 11 (depends on 1)

The image pixel of claim 1, further comprising:
a toroidal microlens that directs light toward the second sub-pixel group.

### Claim 12 (depends on 1)

The image pixel of claim 1, further comprising:
fin structures that connect the inter-pixel light shielding structure and the intra-pixel light shielding structure.

### Claim 13 (depends on 1)

The image pixel of claim 1, wherein the outer sub-pixel group and the inner sub-pixel group are concentric.

### Claim 14 (depends on 1)

The image pixel of claim 1, further comprising:
a toroidal microlens that covers the outer sub-pixel group and that has an opening, wherein the opening in the toroidal microlens overlaps the inner sub-pixel group.

### Claim 15

An image pixel, comprising:
an outer sub-pixel group that includes at least a first sub-pixel, wherein the first sub-pixel has a first light sensitivity;
an inner sub-pixel group that is nested within the outer sub-pixel group and that includes at least a second sub-pixel, wherein the second sub-pixel has a second light sensitivity that is less than the first light sensitivity;
a light filter layer formed over at least the outer sub-pixel group;
a toroidal microlens that covers the outer sub-pixel group and that has an opening, wherein the opening in the toroidal microlens overlaps the inner sub-pixel group;
an inter-pixel light shielding structure that is formed at an outer boundary of the image pixel; and
an intra-pixel light shielding structure that is formed over an outer perimeter of the inner sub-pixel group.

### Claim 16

An image pixel, comprising:
an outer sub-pixel group that includes at least a first sub-pixel that has a first light sensitivity;
an inner sub-pixel group that includes at least a second sub-pixel that has a second light sensitivity that is less than the first light sensitivity, wherein the outer sub-pixel group and the inner sub-pixel group are concentric;
a light filter layer formed over at least the outer sub-pixel group;
an inter-pixel light shielding structure that is formed at an outer boundary of the image pixel; and
an intra-pixel light shielding structure that is formed over an outer perimeter of the inner sub-pixel group.