LIGHT REFLECTION FOR BACKSIDE ILLUMINATED SENSOR

• US 20070001100A1
• Filed: 06/15/2006
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Abandoned Application

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: YAUNG, Dun-Nian, WUU, Shou-Gwo, HSU, Tzu-Hsuan
• Application Number:
  US11/424,286
• Publication Number:
  US 20070001100A1
• Time in Patent Office: Days
• US Class Current: 250/214.100
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14629 Reflectors
• CPC Class Codes: H01L 27/14632 Wafer-level processed structures
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 31/0216 Coatings H01L31/041 takes precedence

Abstract

The present disclosure provides a backside illuminated semiconductor device. The device includes a semiconductor substrate having a front surface and a back surface, a sensor element formed on the front surface of the semiconductor substrate, and a light reflective layer (LRL) disposed over the sensor element. The LRL is configured to reflect light directed towards the back surface and through the sensor element.

Claims

1. A backside illuminated semiconductor device, comprising:

a semiconductor substrate having a front surface and a back surface;

a sensor element formed on the front surface of the semiconductor substrate; and

a light reflective layer (LRL) disposed over the semiconductor substrate, wherein the LRL has a reflective surface to the sensor element, wherein the reflective surface has a surface area substantially at least 80% that of the sensor element.

2. The device of claim 1, wherein the sensor element comprises an active pixel sensor.

3. The device of claim 1, wherein the sensor element comprises a passive pixel sensor.

4. The device of claim 1, wherein the LRL has a reflectivity substantially at least 30% to a backside illuminated light.

5. The device of claim 1, wherein the LRL has a thickness ranging between about 50 angstrom and 20 micrometer.

6. The device of claim 1, wherein the LRL comprises metal.

7. The device of claim 6, wherein the metal comprises aluminum.

8. The device of claim 6, wherein the metal comprises copper.

9. The device of claim 6, wherein the metal comprises tungsten.

10. The device of claim 1, wherein the LRL comprises dielectric.

11. The device of claim 10, wherein the dielectric comprises silicon oxide.

12. The device of claim 10, wherein the dielectric comprises silicon nitride.

13. The device of claim 10, wherein the dielectric comprises silicon oxynitride.

14. The device of claim 10, wherein the dielectric has an extinction coefficient about less than 2.

15. The device of claim 1, wherein the LRL comprises a multilayer structure.

16. A backside illuminated semiconductor device, comprising:

a semiconductor substrate having a front surface and a back surface;

a sensor element formed on the front surface of the semiconductor substrate, wherein the sensor element comprises a light-sensing region; and

a light reflective layer (LRL) disposed over the light-sensing region, wherein the LRL is configured to reflect light back to the light-sensing region.

17. The device of claim 16, wherein the light-sensing region has a doping concentration ranging between about 10¹⁴ and 10²¹ atoms/cm³.

18. The device of claim 16, wherein the light-sensing region has an area ranging between about 10% and 80% of a pixel area of the sensor element.

19. The device of claim 16, wherein the light-sensing region comprises an N-type doped region.

20. The device of claim 16, wherein the light-sensing region comprises a P-type doped region.