Integrated photo sensor

• US 6,333,544 B1
• Filed: 07/26/2000
• Issued: 12/25/2001
• Est. Priority Date: 08/19/1999
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Gotoh, Yoshitaka, Toyoda, Inao
• Primary Examiner(s): CHRISTIANSON, KEITH ALAN
• Application Number:
  US09/625,867
• Time in Patent Office: 517 Days
• Field of Search: 257/431, 257/432, 257/433, 257/434, 257/435, 257/436, 257/552, 257/555
• US Class Current: 257/431
• CPC Class Codes: H01L 27/1443 with at least one potential jump or surface barrier

Abstract

A sensor portion of an integrated photo sensor is composed of a silicon substrate, a photo diode and a signal processing element which are provided on the silicon substrate separately from each other. A shading film is provided on a surface region of the substrate except a region above the photo diode, and an intermediate insulating film made of silicon oxide is provided between the silicon substrate and the shading film. The intermediate insulating film includes a part extending on a light-receiving region of the photo diode, and the part is covered with light transmittable gel having a refractive index approximately equal to that of the intermediate insulating film.

Claims

1. An integrated photo sensor comprising:

a chip;

a light-receiving element provided on the chip for receiving light and converting an amount of the light into an electrical signal;

a signal processing circuit element provided on the chip separately from the light-receiving element, for processing the electrical signal from the light-receiving element;

a shading film provided on the chip to cover the signal processing circuit element and having a window corresponding to a light receiving region on the light-receiving element;

an intermediate insulating film provided between the chip and the shading film, the intermediate insulating film extending on the signal processing circuit element and on the light-receiving element; and

a light transmittable gel provided on the light-receiving element through the intermediate insulating film, the light transmittable gel having a refractive index approximately equal to that of the intermediate insulating film.

2. The integrated photo sensor of claim 1, wherein the light transmittable gel covers the shading film and has a thickness sufficient for protecting the chip.

3. The integrated photo sensor of claim 1, wherein the light transmittable gel has a thickness that is at least 100 times thicker than that of the intermediate insulating film provided on the light-receiving element.

4. The integrated photo sensor of claim 1, wherein:

the light-receiving element is made of silicon; and

the intermediate insulating film is made of silicon oxide.

5. The integrated photo sensor of claim 4, wherein the refractive index of the light transmittable gel is in a range of approximately 1 to 2.13.

6. The integrated photo sensor of claim 1, wherein:

the light-receiving element is made of silicon; and

the intermediate insulating film is made of silicon nitride.

7. The integrated photo sensor of claim 6, wherein the refractive index of the light transmittable gel is in a range of approximately 1 to 4.

8. The integrated photo sensor of claims 1, wherein the light transmittable gel has a thickness larger than approximately 500 nm.

9. An integrated photo sensor comprising:

a chip;

a light-receiving element provided on the chip for receiving light and converting an amount of the light into an electrical signal;

a signal processing circuit element provided on the chip separately from the light-receiving element, for processing the electrical signal from the light-receiving element;

a shading film provided on the chip to cover a surface of the chip other than a light receiving region of the light-receiving element;

an intermediate insulating film including a first part disposed on the signal processing circuit element between the chip and the shading film, and a second part disposed on the light receiving region of the light-receiving element; and

a light transmittable gel provided on the light-receiving element through the intermediate insulating film, the light transmittable gel being thicker than the shading film and filling a step produced between the shading film and the second part of the intermediate insulating film.

10. The integrated photo sensor of claim 9, wherein the light transmittable gel covers the shading film and has a thickness sufficient for protecting the chip.

11. The integrated photo sensor of claim 9, wherein the light transmittable gel has a thickness that is at least 100 times thicker than that of the second part of the intermediate insulating film provided on the light-receiving element.

12. The integrated photo sensor of claim 9, wherein:

the light-receiving element is made of silicon; and

the intermediate insulating film is made of silicon oxide.

13. The integrated photo sensor of claim 12, wherein the light transmittable gel has a refractive index in a range of approximately 1 to 2.13.

14. The integrated photo sensor of claim 9, wherein:

the light-receiving element is made of silicon; and

the intermediate insulating film is made of silicon nitride.

15. The integrated photo sensor of claim 14, wherein the light transmittable gel has a refractive index in a range of approximately 1 to 4.

16. The integrated photo sensor of claim 9, wherein the light transmittable gel has a thickness larger than approximately 500 nm.