Color Filter And Photodiode Patterning Configuration

• US 20150303231A1
• Filed: 02/10/2015
• Published: 10/22/2015
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Optiz, Inc.
• Original Assignee: Optiz, Inc.
• Inventors: Oganesian, Vage, Lu, Zhenhua
• Granted Patent: US 9,985,063 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14667 Colour imagers

Abstract

An imaging device that includes an array of photo detectors each configured to generate an electrical signal in response to received light, and an array of color filters disposed over the array of photo detectors such that the photo detectors receive light passing through the color filters. Each of the color filters has a color transmission characteristic, which vary. To even out color balance, some of the color filters are disposed over a plurality of the photo detectors while others are disposed over only one of the photo detectors. Additional color balance can be achieved by varying the relative area sizes of the color filters and underlying photo detectors based on color transmission characteristics, to compensate for the varying absorption coefficient of the photo detectors at different colors.

Claims

1. An imaging device, comprising:

an array of photo detectors each configured to generate an electrical signal in response to received light; and

an array of color filters disposed over the array of photo detectors such that the photo detectors receive light passing through the color filters, wherein;

each of the color filters has a color transmission characteristic,

the color transmission characteristic of some of the color filters is different from that of others of the color filters,

each of a first plurality of the color filters is disposed over a plurality of the photo detectors, and

each of a second plurality of the color filters is disposed over only one of the photo detectors.

2. The imaging device of claim 1, wherein the first plurality of color filters is disposed along edges of the array of color filters, and the second plurality of color filters is disposed in an inner area of the array of color filters.

3. The imaging device of claim 1, wherein the first plurality of color filters includes a first sub-plurality of the color filters having a first color transmission characteristic, a second sub-plurality of the color filters having a second color transmission characteristic, and a third a third sub-plurality of the color filters having a third color transmission characteristic, and wherein the first, second and third color transmission characteristics are different from each other.

4. The imaging device of claim 3, wherein the second plurality of color filters includes a first sub-plurality of the color filters having the first color transmission characteristic, a second sub-plurality of the color filters having the second color transmission characteristic, and a third a third sub-plurality of the color filters having the third color transmission characteristic.

5. The imaging device of claim 4, wherein:

the first color transmission characteristic is a red color transmission characteristic;

the second color transmission characteristic is a green color transmission characteristic; and

the third color transmission characteristic is a blue color transmission characteristic.

6. The imaging device of claim 3, wherein:

the first plurality of color filters includes a fourth sub-plurality of the color filters having a fourth color transmission characteristic different from the first, second and third color transmission characteristics.

the second plurality of color filters includes a first sub-plurality of the color filters having the first color transmission characteristic, a second sub-plurality of the color filters having the second color transmission characteristic, a third a third sub-plurality of the color filters having the third color transmission characteristic, and a fourth sub-plurality of the color filters having the fourth color transmission characteristic.

7. The imaging device of claim 6, wherein:

the first color transmission characteristic is a red color transmission characteristic;

the second color transmission characteristic is a green color transmission characteristic;

the third color transmission characteristic is a blue color transmission characteristic; and

the fourth color transmission characteristic is a white color transmission characteristic.

8. The imaging device of claim 7, wherein the color filters having the white color transmission characteristic are each formed of a transparent material or an aperture, for transmitting all colors of visible light.

9. An imaging device, comprising:

an array of photo detectors each configured to generate an electrical signal in response to received light;

an array of color filters disposed over the array of photo detectors such that the photo detectors receive light passing through the color filters, wherein the array of color filters includes;

a first plurality of the color filters having a first color transmission characteristic and disposed over a first plurality of the photo detectors,

a second plurality of the color filters having a second color transmission characteristic and disposed over a second plurality of the photo detectors, and

a third plurality of the color filters having a third color transmission characteristic and disposed over a third plurality of the photo detectors,

wherein the first, second and third color transmission characteristics are different from each other;

the array of photo detectors having a first absorption coefficient corresponding to the first color transmission characteristic, a second absorption coefficient corresponding to the second color transmission characteristic, and a third absorption coefficient corresponding to the third color transmission characteristic, wherein the first absorption coefficient is greater than the second absorption coefficient, and the second absorption coefficient is greater than the third absorption coefficient;

the third plurality of the color filters covers a larger area of the array of photo detectors than does the second plurality of the color filters; and

the second plurality of the color filters covers a larger area of the array of photo detectors than does the first plurality of the color filters.

10. The imaging device of claim 9, wherein:

the first, second and third pluralities of the photo detectors all have a same lateral size;

each of the first plurality of the color filters is disposed over one of the first plurality of the photo detectors;

each of the second plurality of the color filters is disposed over one of the second plurality of the photo detectors;

each of the third plurality of the color filters is disposed over one of the third plurality of the photo detectors;

the third plurality of the photo detectors includes a greater number of the photo detectors than does the second plurality of the photo detectors;

the second plurality of the photo detectors includes a greater number of the photo detectors than does the first plurality of the photo detectors;

the third plurality of the color filters includes a greater number of the color filters than does the second plurality of the color filters; and

the second plurality of the color filters includes a greater number of the color filters than does the first plurality of the color filters.

11. The imaging device of claim 9, wherein the array of color filters further includes a fourth plurality of the color filters having a white color transmission characteristic and disposed over a fourth plurality of the photo detectors.

12. The imaging device of claim 11, wherein:

the first color transmission characteristic is a blue color transmission characteristic;

the second color transmission characteristic is a green color transmission characteristic; and

the third color transmission characteristic is a red color transmission characteristic.

13. The imaging device of claim 9, wherein:

each of the first plurality of the color filters is disposed over one of the first plurality of the photo detectors;

each of the second plurality of the color filters is disposed over one of the second plurality of the photo detectors;

each of the third plurality of the color filters is disposed over one of the third plurality of the photo detectors;

each of the third plurality of the photo detectors is larger in lateral size than each of the second plurality of the photo detectors;

each of the second plurality of the photo detectors is larger in lateral size than each of the first plurality of the photo detectors;

each of the third plurality of the color filters is larger in lateral size than each of the second plurality of the color filters; and

each of the second plurality of the color filters is larger in lateral size than each of the first plurality of the color filters.

14. The imaging device of claim 13, wherein the array of color filters is arranged in repeating blocks of the color filters, and wherein each of the repeating blocks includes only one of the first plurality of the color filters, only one of the second plurality of the color filters, and only one of the third plurality of the color filters.

15. The imaging device of claim 14, wherein the array of color filters further includes a fourth plurality of the color filters having a white color transmission characteristic and disposed over a fourth plurality of the photo detectors, and wherein each of the repeating blocks includes only one of the fourth plurality of the color filters.

16. The imaging device of claim 15, wherein:

the first color transmission characteristic is a blue color transmission characteristic;

the second color transmission characteristic is a green color transmission characteristic; and

the third color transmission characteristic is a red color transmission characteristic.

17. The imaging device of claim 13, wherein each of the third plurality of the color filters is L-shaped.

18. The imaging device of claim 17, wherein each of the third plurality of the photo detectors is L-shaped.

19. The imaging device of claim 13, wherein each of the third plurality of the color filters is U-shaped.

20. The imaging device of claim 19, wherein each of the third plurality of the photo detectors is U-shaped.