Stacked semiconductor radiation sensors having color component and infrared sensing capability

• US 20040125222A1
• Filed: 12/30/2002
• Published: 07/01/2004
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Bell, Cynthia S., Haussecker, Horst, Bradski, Gary R.
• Granted Patent: US 7,154,157 B2
• Time in Patent Office: Days
• US Class Current: 348/272
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14652 Multispectral infrared imagers, having a stacked pixel-element structure, e.g. npn, npnpn or MQW structures
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/20 for generating image signals from infrared radiation only
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 5/2226 Determination of depth image, e.g. for foreground/background separation determining depth by image analysis in general G06T7/50; segmentation by image analysis in general G06T7/10
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A radiation sensing structure includes red, green and blue photodiodes stacked Above an infrared radiation sensing photodiode.

Claims

1. A sensing structure, comprising:

a first junction formed at a first depth in a semiconductor substrate to sense infrared radiation; and

a second junction formed at a second depth in the semiconductor substrate to sense visible radiation, the second depth being less deep than the first depth.

2. The sensing structure of claim 1, wherein the second junction at least partially overlies the first junction.

3. The sensing structure of claim 1, wherein the second junction is positioned to sense a red light component;

and further comprising;

a third junction formed at a third depth in the semiconductor substrate to sense a green light component; and

a fourth junction formed at a fourth depth in the semiconductor substrate to sense a blue light component;

the third depth being less deep than the second depth, and the fourth depth being less deep than the third depth.

4. The sensing structure of claim 3, wherein the third junction at least partially overlies the second junction, and the fourth junction at least partially overlies the third junction.

5. The sensing structure of claim 3, further comprising an infrared pass filter positioned above the first junction and below the second junction;

the infrared pass filter having a filter characteristic to substantially attenuate visible radiation and to substantially pass infrared radiation.

6. The sensing structure of claim 5, further comprising an infrared-notch filter positioned above the fourth junction, and having a filter characteristic to substantially pass visible radiation and to substantially attenuate infrared radiation that has a wavelength that differs from a notch wavelength, and to substantially pass infrared radiation that has the notch wavelength.

7. The sensing structure of claim 6, wherein the notch wavelength is selected from the group consisting of 830 nm, 880 nm and 940 nm.

8. The sensing structure of claim 3, further comprising an infrared-notch filter positioned above the fourth junction, and having a filter characteristic to substantially pass visible radiation and to substantially attenuate infrared radiation that has a wavelength that differs from a notch wavelength, and to substantially pass infrared radiation that has the notch wavelength.

9. The sensing structure of claim 8, wherein the notch wavelength is selected from the group consisting of 830 nm, 880 nm and 940 nm.

10. The sensing structure of claim 1, wherein the semiconductor substrate includes silicon.

11. A pixel sensor, comprising:

an infrared photodiode;

a red photodiode at least partially superimposed on the infrared photodiode;

a green photodiode at least partially superimposed on the red photodiode; and

a blue photodiode at least partially superimposed on the green photodiode.

12. The pixel sensor of claim 11, further comprising an infrared-pass filter interposed between the infrared photodiode and the red photodiode.

13. The pixel sensor of claim 12, further comprising an infrared-notch filter superimposed on the blue photodiode.

14. The pixel sensor of claim 11, further comprising an infrared-notch filter superimposed on the blue photodiode.

15. A pixel sensor, comprising:

a first infrared photodiode to detect infrared radiation of a first wavelength;

a second infrared diode, at least partially superimposed on the first infrared diode, to detect infrared radiation of a second wavelength that is shorter than the first wavelength;

a red photodiode at least partially superimposed on the second infrared photodiode;

a green photodiode at least partially superimposed on the red photodiode; and

a blue photodiode at least partially superimposed on the green photodiode.

16. The pixel sensor of claim 15, further comprising an infrared-pass filter interposed between the second infrared photodiode and the red photodiode.

17. The pixel sensor of claim 15, further comprising a dual-infrared-notch filter superimposed on the blue photodiode.

18. A pixel imaging array, comprising a matrix of rows and columns of sensor structures, each sensor structure including:

an infrared photodiode;

a red photodiode at least partially superimposed on the infrared photodiode;

a green photodiode at least partially superimposed on the red photodiode; and

a blue photodiode at least partially superimposed on the green photodiode.

19. The pixel imaging array of claim 18, further comprising an infrared-notch filter superimposed on the matrix of sensor structures.

20. The pixel imaging array of claim 18, further comprising a read circuit to generate respective electrical signals from each of the photodiodes.

21. A color and depth information camera, comprising:

a pixel imaging array that includes a matrix of rows and columns of sensor structures, each sensor structure including;

an infrared photodiode;

a red photodiode at least partially superimposed on the infrared photodiode;

a green photodiode at least partially superimposed on the red photodiode; and

a blue photodiode at least partially superimposed on the green photodiode;

an optical system to form an image on the pixel imaging array;

a control circuit coupled to the pixel imaging array; and

an infrared radiation source coupled to the control circuit.

22. The camera of claim 21, wherein the control circuit is operative to cause the infrared radiation source to emit an infrared pulse;

and

read the infrared photodiodes in timed relation to the infrared pulse to obtain depth information from a scene illuminated by the infrared pulse.

23. The camera of claim 21, further comprising a shutter coupled to the control circuit and disposed in front of the pixel imaging array;

the control circuit operative to

cause the infrared radiation source to emit an infrared pulse;

open and close the shutter in timed relation to the infrared pulse; and

read the infrared diodes to obtain depth information from a scene illuminated by the infrared pulse.

24. The camera of claim 21, wherein:

the pixel imaging array includes an infrared-notch filter superimposed on the blue photo diodes, the filter having a characteristic to pass infrared radiation at a notch wavelength; and

the infrared radiation source is operative to emit infrared radiation at the notch wavelength.

25. The camera of claim 24, wherein the notch wavelength is selected from the group consisting of 830 nm, 880 nm and 940 nm.