Solid-state imaging device

• US 9,349,766 B2
• Filed: 08/07/2014
• Issued: 05/24/2016
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sugiura, Yuki
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US14/453,715
• Publication Number:
  US 20150255498A1
• Time in Patent Office: 656 Days
• Field of Search: 257/432
• US Class Current: 1/1
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/1461 characterised by the photosensitive area
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14665 Imagers using a photoconductor layer
• CPC Class Codes: H01L 27/14667 Colour imagers
• CPC Class Codes: H10K 39/32 Organic image sensors

Abstract

According to one embodiment, a solid-state imaging device includes a semiconductor layer, an organic photoelectric conversion layer, and microlenses. A plurality of photoelectric conversion elements are provided in the semiconductor layer. The organic photoelectric conversion layer is provided on a light receiving surface of the semiconductor layer, absorbs and photoelectrically converts light of a predetermined wavelength region, and transmits light of a wavelength region except for the predetermined wavelength region. The microlenses are provided at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements with the organic photoelectric conversion layer interposed therebetween, and concentrate incident light on the photoelectric conversion elements.

Claims

1. A solid-state imaging device comprising:

a semiconductor layer in which a plurality of photoelectric conversion elements that photoelectrically convert incident light are provided;

an organic photoelectric conversion layer that is provided on a light receiving surface of the semiconductor layer, that absorbs and photoelectrically converts light of a predetermined wavelength region, and that transmits light of a wavelength region except for the predetermined wavelength region;

microlenses that are provided at positions facing the light receiving surfaces of the plurality of photoelectric conversion elements with the organic photoelectric conversion layer interposed therebetween, and that concentrate incident light on the photoelectric conversion elements;

a first transparent electrode that is provided on a light receiving surface of the organic photoelectric conversion layer;

a plurality of second transparent electrodes that is provided on a surface of the organic photoelectric conversion layer opposite to the light receiving surface,

wherein the organic photoelectric conversion layer and the first transparent electrode are provided so as to cover a region including the light receiving surfaces of the plurality of photoelectric conversion elements,

the second transparent electrodes are provided so that a part of a projection region, which is formed by projecting an image of the second transparent electrode on the semiconductor layer, covers a part of the light receiving surface of the adjacent photoelectric conversion element;

storage diodes that are provided in the semiconductor layer on a surface of the semiconductor layer opposite to the light receiving surface and hold charges collected by the second transparent electrodes;

contact plugs that are embedded in the semiconductor layer, that connect the second transparent electrodes to the storage diodes, and that discharge the charges to the storage diodes from the second transparent electrodes;

floating diffusions that are provided in the semiconductor layer on a surface of the semiconductor layer opposite to the light receiving surface and that accumulate the charges transferred from the storage diodes; and

readout gates that are provided on a surface of the semiconductor layer opposite to the light receiving surface and that transfer the charges to the floating diffusions from the storage diodes.

2. The solid-state imaging device according to claim 1,

wherein the organic photoelectric conversion layer absorbs light of the predetermined wavelength region corresponding to green.

3. The solid-state imaging device according to claim 1,

wherein an installation area of the microlenses is larger than an area of the light receiving surface of the photoelectric conversion element facing the microlenses.

4. The solid-state imaging device according to claim 1, further comprising:

color filters that are provided between the semiconductor layer and the organic photoelectric conversion layer at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements and that transmit light of a wavelength region except for the predetermined wavelength region.

5. The solid-state imaging device according to claim 1, further comprising:

light shielding members that are provided on a side, on which light is incident, of regions between the adjacent photoelectric conversion elements of the semiconductor layer and shield light.

6. The solid-state imaging device according to claim 1, further comprising:

storage diodes that are provided in the semiconductor layer on a side of the semiconductor layer opposite to the light receiving surface and that hold charges collected by the second transparent electrodes;

floating diffusions that are provided adjacent to the storage diodes and that accumulate the charges transferred from the storage diodes; and

amplifying transistors which are provided in the semiconductor layer on a side of the semiconductor layer opposite to the light receiving surface and that amplify charges accumulated in the floating diffusions and of which gates are connected to the floating diffusion through lines.

7. The solid-state imaging device according to claim 1, further comprising:

color filters that are provided at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements with the organic photoelectric conversion layer interposed therebetween, and that transmit light of the predetermined wavelength region and light of a wavelength region shorter than the predetermined wavelength region or light of a wavelength region longer than the predetermined wavelength region.

8. The solid-state imaging device according to claim 1, further comprising:

a first transparent electrode that is provided on a light receiving surface of the organic photoelectric conversion layer; and

a plurality of second transparent electrodes that is provided on a surface of the organic photoelectric conversion layer opposite to the light receiving surface,

wherein the organic photoelectric conversion layer and the first transparent electrode are provided so as to cover a region including the light receiving surfaces of the plurality of photoelectric conversion elements, and

the second transparent electrodes are provided at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements.

9. The solid-state imaging device according to claim 1, wherein center positions of the microlenses correspond to center positions of the photoelectric conversion elements and the microlenses are provided at positions shifted from center positions of the second transparent electrodes in plan view.

10. A solid-state imaging device comprising:

a semiconductor layer in which a plurality of photoelectric conversion elements that photoelectrically convert incident light is provided;

an organic photoelectric conversion layer that is provided on a light receiving surface of the semiconductor layer, that absorbs and photoelectrically converts light of a predetermined wavelength region, and that transmits light of a wavelength region except for the predetermined wavelength region;

microlenses that are provided at positions facing the light receiving surfaces of the plurality of photoelectric conversion elements with the organic photoelectric conversion layer interposed therebetween, and that concentrate incident light on the photoelectric conversion elements;

a first transparent electrode that is provided on a light receiving surface of the organic photoelectric conversion layer;

a plurality of second transparent electrodes that is provided on a surface of the organic photoelectric conversion layer opposite to the light receiving surface,

wherein the organic photoelectric conversion layer and the first transparent electrode are provided so as to cover a region including the light receiving surfaces of the plurality of photoelectric conversion elements,

the second transparent electrodes are provided so that a part of a projection region, which is formed by projecting an image of the second transparent electrode on the semiconductor layer, covers a part of the light receiving surface of the adjacent photoelectric conversion element;

wherein center positions of the microlenses correspond to center positions of the photoelectric conversion elements and the microlenses are provided at positions shifted from center positions of the second transparent electrodes in plan view.

11. The solid-state imaging device according to claim 10,

wherein the organic photoelectric conversion layer absorbs light of the predetermined wavelength region corresponding to green.

12. The solid-state imaging device according to claim 10,

wherein an installation area of the microlenses is larger than an area of the light receiving surface of the photoelectric conversion element facing the microlenses.

13. The solid-state imaging device according to claim 10, further comprising:

color filters that are provided between the semiconductor layer and the organic photoelectric conversion layer at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements and that transmit light of a wavelength region except for the predetermined wavelength region.

14. The solid-state imaging device according to claim 10, further comprising:

light shielding members that are provided on a side, on which light is incident, of regions between the adjacent photoelectric conversion elements of the semiconductor layer and shield light.

15. The solid-state imaging device according to claim 10, further comprising:

storage diodes that are provided in the semiconductor layer on a side of the semiconductor layer opposite to the light receiving surface and that hold charges collected by the second transparent electrodes;

floating diffusions that are provided adjacent to the storage diodes and that accumulate the charges transferred from the storage diodes; and

amplifying transistors which are provided in the semiconductor layer on a side of the semiconductor layer opposite to the light receiving surface and that amplify charges accumulated in the floating diffusions and of which gates are connected to the floating diffusion through lines.

16. The solid-state imaging device according to claim 10, further comprising:

color filters that are provided at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements with the organic photoelectric conversion layer interposed therebetween, and that transmit light of the predetermined wavelength region and light of a wavelength region shorter than the predetermined wavelength region or light of a wavelength region longer than the predetermined wavelength region.

17. The solid-state imaging device according to claim 10, further comprising:

a first transparent electrode that is provided on a light receiving surface of the organic photoelectric conversion layer; and

a plurality of second transparent electrodes that is provided on a surface of the organic photoelectric conversion layer opposite to the light receiving surface,

wherein the organic photoelectric conversion layer and the first transparent electrode are provided so as to cover a region including the light receiving surfaces of the plurality of photoelectric conversion elements, and

the second transparent electrodes are provided at positions facing the respective light receiving surfaces of the plurality of photoelectric conversion elements.