Solid state image pickup device with mirrors

• US 5,172,206 A
• Filed: 07/30/1991
• Issued: 12/15/1992
• Est. Priority Date: 07/30/1990
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Iizuka, Yasuo
• Primary Examiner(s): Mintel, William
• Application Number:
  US07/738,094
• Time in Patent Office: 504 Days
• Field of Search: 357/30 L, 357/30 H, 357/30 P, 357/30 D, 357/30 G, 357/30 R, 357/30 K, 357/32, 357/68, 357/4, 357/24
• US Class Current: 257/291
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 31/02162 for filtering or shielding light, e.g. multicolour filters for photodetectors
• CPC Class Codes: H01L 31/02164 for shielding light, e.g. light blocking layers, cold shields for infrared detectors
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216

Abstract

There is provided a solid state image pickup device, comprising: a semiconductor substrate; a plurality of photosensitive elements formed on the surface of the semiconductor substrate; light shielding elements positioned above the substrate for covering the regions other than the photosensitive elements; a plurality of light converging elements each for converging an incident light to each of the photosensitive elements, the light converging elements being formed above the photosensitive elements at the level above the light shielding elements at a predetermined pitch; and reflecting elements formed between non-lens regions between the light converging elements and the light shielding elements, the reflecting elements each having a reflection surface for reflecting a light incident to the converging means and the non-lens regions or at least a light incident to the non-lens region toward the photosensitive element.

Claims

1. A solid state image pickup device, comprising:

a semiconductor substrate;

a plurality of photosensitive means formed on the surface of said semiconductor substrate;

light shielding means positioned above said substrate for covering the regions other than said phtoosensitive means;

a plurality of light converging means for converging an incident light to each of said photosensitive means, said light converging means defining a plurality of lens regions and being formed above said photosensitive means and above said light shielding means at a predetermined pitch, said pitch defining non-lens region; and

reflecting means formed under said non-lens regions and above said light shielding means, said reflecting means having a reflection surface for reflecting a light incident to said converging means and said non-lens regions towards said photosensitive means.

3. An image pickup device according to claim 1, wherein each of said reflecting means is configured in a frame, said frame being positioned about an axis perpendicular to said semiconductor substrate and passing through each of said photosensitive means, and the inner surface of said frame constituting a reflection surface for reflecting a light incident to said inner surface toward said photosensitive means.

5. An image pickup device according to claim 3, wherein said reflecting means is configured in a rectangular shape.

7. An image pickup device according to claim 1, wherein said light shielding means has a side reflection surface for reflecting a light incident to said reflection surface toward said photosensitive means.

9. An image pickup device according to claim 1, wherein said reflecting means is made of aluminum and obtained by etching an aluminum film covered over the whole surface above said light shielding means.

11. An image pickup device according to claim 3, wherein said reflecting means is made of aluminum and obtained by etching an aluminum film covered over the whole surface above said light shielding means.

13. An image pickup device according to claim 1, wherein said reflecting means is made of aluminum and obtained by etching an insulating film covered over the whole surface above said light shielding means and partially depositing an aluminum film on said insulating film.

15. An image pickup device according to claim 3, wherein said reflecting means is made of aluminum and obtained by etching an insulating film covered over the whole surface above said light shielding means and partially depositing an aluminum film on said insulating film.

17. An image pickup device according to claim 1, wherein said light shielding means and said reflecting means are formed integrally.

19. An image pickup device according to claim 1, further comprising color filter means disposed between said reflecting means and said light converging means, said color filter means filters said incident light by only passing light having a predetermined wavelength.

21. An image pickup device according to claim 3, further comprising color filter means disposed between said reflecting means and said light converging means, said color filter means filters said incident light by only passing light having a predetermined wavelength.

2. A solid state image pickup device, comprising:

a semiconductor substrate;

a plurality of photosensitive means formed on the surface of said semiconductor substrate;

light shielding means positioned above said substrate for covering the regions other than said photosensitive means;

a plurality of light converging means for converging an incident light to each of said photosensitive means, said light converging means defining a plurality of lens regions and being formed above said photosensitive means and above said light shielding means at a predetermined pitch, said pitch defining non-lens regions; and

reflecting means formed under said non-lens regions and above said light shielding means, said reflecting means having a reflection surface for reflecting at least a light incident to said non-lens regions toward said photosensitive means.

4. An image pickup device according to claim 2, wherein each of said reflecting means is configured in a frame, said frame being positioned about an axis perpendicular to said semiconductor substrate and passing through each of said photosensitive means, and the inner surface of said frame constituting a reflection surface for reflecting a light incident to said inner surface toward said photosensitive means.

6. An image pickup device according to claim 4, wherein said reflecting means is configured in a rectangular shape.

8. An image pickup device according to claim 2, wherein said light shielding means has a side reflection surface for reflecting a light incident to said reflection surface toward said photosensitive means.

10. An image pickup device according to claim 2, wherein said reflecting means is made of aluminum and obtained by etching an aluminum film covered over the whole surface above said light shielding means.

12. An image pickup device according to claim 4, wherein said reflecting means is made of aluminum and obtained by etching an aluminum film covered over the whole surface above said light shielding means.

14. An image pickup device according to claim 2, wherein said reflecting means is made of aluminum and obtained by etching an insulating film covered over the whole surface above said light shielding means and partially depositing an aluminum film on said insulating film.

16. An image pickup device according to claim 4, wherein said reflecting means is made of aluminum and obtained by etching an insulating film covered over the whole surface above said light shielding means and partially depositing an aluminum film on said insulating film.

18. An image pickup device according to claim 2, wherein said light shielding means and said reflecting means are formed integrally.

20. An image pickup device according to claim 2, further comprising color filter means disposed between said reflecting means and said light converging means, said color filter means filters said incident light by only passing light having a predetermined wavelength.

22. An image pickup device according to claim 4, further comprising color filter means disposed between said reflecting means sand said light converging means, said color filter means filters said incident light by only passing light having a predetermined wavelength.