IMAGE PICKUP DEVICE, METHOD OF PRODUCING IMAGE PICKUP DEVICE, AND SEMICONDUCTOR SUBSTRATE FOR IMAGE PICKUP DEVICE

• US 20080297634A1
• Filed: 05/23/2008
• Published: 12/04/2008
• Est. Priority Date: 05/31/2007
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: UYA, Shinji
• Granted Patent: US 8,063,959 B2
• Time in Patent Office: Days
• US Class Current: 348/294
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H01L 27/1463 Pixel isolation structures
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14687 Wafer level processing

Abstract

An image pickup device including a semiconductor substrate that is irradiated with light from a first surface side thereof, and reading signal charges generated in the semiconductor substrate in accordance with the light from a second surface side thereof, wherein the semiconductor substrate includes: a photoelectric converting layer that includes a plurality of impurity diffusion layers on the second surface side of the semiconductor substrate, and that produces the signal charges by photoelectric conversion; and an embedded member that includes a light blocking material, and that is embedded in an impurity diffusion layer on a surface side of the photoelectric converting layer, the surface side facing the second surface side of the semiconductor substrate.

Claims

1. An image pickup device comprising a semiconductor substrate that is irradiated with light from a first surface side thereof, and taking an image by reading signal charges generated in the semiconductor substrate in accordance with the light from a second surface side thereof,

wherein

the semiconductor substrate comprises:

a photoelectric converting layer that includes a plurality of impurity diffusion layers on the second surface side of the semiconductor substrate, and that produces the signal charges by photoelectric conversion; and

an embedded member that includes a light blocking material, and that is embedded in an impurity diffusion layer on a surface side of the photoelectric converting layer to which the light irradiated on the first surface side of the semiconductor substrate is entered.

2. The image pickup device as claimed in claim 1,

wherein

the embedded member comprises a plurality of light blocking members that are placed in boundaries of adjacent pixels.

3. The image pickup device as claimed in claim 2,

wherein

the photoelectric converting layer comprises a pixel separation region that is formed in the boundaries of the adjacent pixels, and

the light blocking members are formed adjoining the pixel separation region.

4. The image pickup device as claimed in claim 2,

wherein

outer circumferences of the light blocking members are covered by an insulating material.

5. The image pickup device as claimed in claim 4,

wherein

a negative voltage is applied to the light blocking members.

6. The image pickup device as claimed in claim 4,

wherein

the insulating material comprises one of an insulating film that is formed by performing a heat treatment on a light blocking member made of a metal material, and a silicide oxide film of a metal material.

7. The image pickup device as claimed in claim 2,

wherein

the light blocking members are covered by a non-depleted layer of the impurity diffusion layers.

8. The image pickup device as claimed in claim 7,

wherein

the light blocking members are grounded.

9. The image pickup device as claimed in claim 1,

wherein

the embedded member is formed in at least one of the first surface side and the second surface side of the semiconductor substrate, and includes an alignment mark that is used as a positional reference of an optical element to be disposed on the semiconductor substrate, during production of the image pickup device.

10. The image pickup device as claimed in claim 1,

wherein

the semiconductor substrate comprises a color filter layer that includes a plurality of color filters transmitting light of different wavelengths, respectively, and that is formed on the first surface side thereof.

11. The image pickup device as claimed in claim 1,

wherein

the semiconductor substrate comprises:

an oxide film; and

an antireflection film, the oxide film and the antireflection film being formed on the first surface side of the semiconductor substrate, and

one of the oxide film and the antireflection film comprises a light blocking film that is placed in boundaries of adjacent pixels outer circumference thereof.

12. The image pickup device as claimed in claim 1, having a ratio of a thickness of the photoelectric converting layer to a pixel size thereof, the ratio being 4 or more.

13. The image pickup device as claimed in claim 1,

wherein

the pixel size is 2 μ

m square or less.

14. The image pickup device as claimed in claim 1,

wherein

the photoelectric converting layer has a thickness of 8 μ

m or more.

15. A method of producing an image pickup device comprising a semiconductor substrate that is irradiated with light from a rear side thereof, and taking an image by reading signal charges generated in the semiconductor substrate in accordance with the light from a surface side thereof,

the method comprising:

pattern-forming a first alignment mark on a first surface side of a silicon layer;

forming an epitaxial layer on the silicon layer by epitaxial growth;

pattern-forming a second alignment mark on the first surface of the epitaxial layer by using the first alignment mark as a reference;

forming a sensor region that includes a plurality of impurity diffusion layers in the epitaxial layer; and

bonding a supporting substrate to the surface side of the epitaxial layer,

wherein

the forming of the sensor region comprises positioning the sensor region by using the second alignment mark as a reference.

16. The method as claimed in claim 15,

wherein

the epitaxial growth is performed by using a method of Epitaxial Lateral Overgrowth.

17. The method as claimed in claim 15,

wherein

the forming of the first alignment mark comprises forming a plurality of light blocking members in boundaries of adjacent pixels by using a material that is identical with a material of the first alignment mark, and that has a light blocking property.

18. The method as claimed in claim 15, further comprising:

forming an oxide film and an antireflection film on a second surface side of the epitaxial layer; and

forming a light blocking film that is placed in the boundaries of the adjacent pixels, outside one of the oxide film and the antireflection film.

19. The method as claimed in claim 15, further comprising:

forming an oxide film and an antireflection film on the second surface side of the epitaxial layer;

forming a third alignment mark outside one of the oxide film and the antireflection film;

forming a color filter layer having plural color filters which transmit light of different wavelengths, respectively, on the second surface side of the epitaxial layer; and

positioning the color filter layer by using the third alignment mark as a reference.

20. The method as claimed in claim 17, further comprising:

forming a pixel separation region in the boundaries of the adjacent pixels so that each of the light blocking members and the pixel separation region are contacted with each other.

21. The method as claimed in claim 17,

wherein

outer circumferences of the light blocking members are covered by an insulating material.

22. The method as claimed in claim 21,

wherein

the insulating material comprises one of an insulating film that is formed by performing a heat treatment on a light blocking member made of a metal material, and a silicide oxide film of a metal material.

23. The method as claimed in claim 17,

wherein

the light blocking members are covered by a non-depleted layer of the epitaxial layer.

24. A semiconductor substrate for an image pickup device comprising a semiconductor substrate that is irradiated with light from a first surface side thereof, and taking an image by reading signal charges generated in the semiconductor substrate in accordance with the light from a second surface side thereof,

the semiconductor substrate comprising:

a photoelectric converting layer that includes a plurality of impurity diffusion layers on the first surface side of the semiconductor substrate, and that produces the signal charges by photoelectric conversion; and

an embedded member that includes a light blocking material, and that is embedded in an impurity diffusion layer on a surface side of the photoelectric converting layer, the surface side facing the second surface side of the semiconductor substrate.