Image sensor and method of manufacturing the same

• US 9,373,656 B2
• Filed: 12/22/2014
• Issued: 06/21/2016
• Est. Priority Date: 03/07/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Jung-Ho
• Primary Examiner(s): Nguyen, Dao H
• Assistant Examiner(s): Nguyen, Tram H
• Application Number:
  US14/579,311
• Publication Number:
  US 20150255495A1
• Time in Patent Office: 547 Days
• Field of Search: 257/57, 257/59, 257/72, 257/83, 257/257, 257/290, 257/40, 257/80, 257/99, 257642-643, 257/759, 257/E33.059, 257/E21.503, 257E51001-E51052, 257E25008-E25009, 257/223, 257/227, 257/291, 257/439, 257/443, 257/655, 257/E27.1, 257/E27.125, 257/E27.112, 257/E29.117, 257/E29.145, 257/E29.147, 257/E29.151, 257/E29.181, 257/E29.202, 257E29273-E29299, 257/E29.314, 257/E29.32, 257/E23.016, 257/E21.094, 257/E21.104, 257/E21.121, 257/E21.372, 257E21411-E21416, 438/149, 438/163, 438/30, 438/48, 438/128, 438/151, 438/157, 438/161, 438/283, 438/29, 438/69, 438/82, 438/99, 438/28
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/11 Manufacturing methods
• CPC Class Codes: H01L 24/03 Manufacturing methods
• CPC Class Codes: H01L 24/08 of an individual bonding area
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/1463 Pixel isolation structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14654 Blooming suppression
• CPC Class Codes: H01L 27/14689 MOS based technologies

Abstract

Image sensor and method of manufacturing the same are provided. The image sensor includes a semiconductor substrate including a pixel area, a voltage connection area, and a pad area, a plurality of photoelectric conversion devices in the pixel area, an anti-reflective layer on a back side of the semiconductor substrate and on the plurality of photoelectric conversion devices, a device isolation structure between the plurality of photoelectric conversion devices, at least one voltage connection structure in the voltage connection area, and electrically connected to the device isolation structure, at least one voltage applying device electrically connected to the at least one voltage connection structure, an internal circuit including at least one conductive inner wire and at least one conductive inner via in an insulating layer, and a through via structure in the pad area.

Claims

1. An image sensor, comprising:

a semiconductor substrate including a pixel area, a voltage connection area, and a pad area;

a plurality of photoelectric conversion devices in the pixel area;

an anti-reflective layer on a back side of the semiconductor substrate and on the plurality of photoelectric conversion devices;

a device isolation structure between the plurality of photoelectric conversion devices;

at least one voltage connection structure in the voltage connection area electrically connected to the device isolation structure;

at least one voltage applying device electrically connected to the at least one voltage connection structure and configured to apply a voltage to the device isolation structure;

an internal circuit, including at least one conductive inner wire and at least one conductive inner via, in an insulating layer on a front side of the semiconductor substrate; and

a through via structure in the pad area electrically connected to the internal circuit through the semiconductor substrate.

2. The image sensor according to claim 1, wherein the voltage is a negative voltage.

3. The image sensor according to claim 1, wherein the device isolation structure comprises a grid.

4. The image sensor according to claim 1, wherein the device isolation structure comprises a deep trench isolation (DTI) structure.

5. The image sensor according to claim 4, wherein the device isolation structure comprises:

a device isolation trench projecting into at least a portion of the semiconductor substrate from the back side of the semiconductor substrate toward the front side;

a device isolation insulating pattern conformal with an inner wall of the device isolation trench;

a first device isolation conductive pattern conformal with the device isolation insulating pattern; and

a second device isolation conductive pattern inside the device isolation trench on the first device isolation conductive pattern,

wherein the device isolation insulating pattern is materially in continuity with the anti-reflective layer, and a front end of the device isolation structure projects more than the back side of the semiconductor substrate.

6. The image sensor according to claim 5, wherein the voltage connection structure comprises:

a voltage connection contact plug projecting into the semiconductor substrate in the voltage connection area, and being in direct contact with the internal circuit electrically connected to the voltage applying device; and

a voltage connection insulating area being spaced apart from and covering a side of the voltage connection contact plug.

7. The image sensor according to claim 6, wherein the voltage connection contact plug comprises:

a voltage connection contact hole projecting into the semiconductor substrate and exposing the internal circuit;

a first voltage connection conductive pattern conformal with an inner wall of the voltage connection contact hole; and

a second voltage connection conductive pattern inside the voltage connection contact hole on the first voltage connection conductive pattern,

wherein the first voltage connection conductive pattern is materially in continuity with the first device isolation conductive pattern, and the second voltage connection conductive pattern is materially in continuity with the second device isolation conductive pattern.

8. The image sensor according to claim 6, wherein the voltage connection insulating area comprises:

a voltage connection insulating trench vertically projecting into the semiconductor substrate at a desired distance from and covering a side of the voltage connection contact plug; and

a voltage connection insulating pattern inside the voltage connection insulating trench,

wherein the voltage connection insulating pattern is materially in continuity with the device isolation insulating pattern.

9. The image sensor according to claim 7, wherein the through via structure comprises:

a through via contact plug projecting into the semiconductor substrate in the pad area and being in direct contact with the internal circuit; and

a through via insulating area being spaced apart from and covering a side of the through via contact plug.

10. The image sensor according to claim 9, wherein the through via contact plug comprises:

a through via contact hole projecting into the semiconductor substrate and exposing the internal circuit;

a first through via conductive pattern conformal with an inner wall of the through via contact hole; and

a second through via conductive pattern inside the through via contact hole on the first through via conductive pattern,

wherein the first through via conductive pattern includes a same material at the same level as the first device isolation conductive pattern, and the second through via conductive pattern includes a same material at the same level as the second device isolation conductive pattern.

11. The image sensor according to claim 9, wherein the through via insulating area comprises:

a through via insulating trench vertically projecting into the semiconductor substrate to be spaced at a desired distance from and cover a side of the through via contact plug; and

a through via insulating pattern inside the through via insulating trench,

wherein the through via insulating pattern is materially in continuity with the device isolation insulating pattern.

12. The image sensor according to claim 10, further comprising:

a protective film conformal with the anti-reflective layer, the device isolation structure, the voltage connection structure, and the through via structure, and including a first pad connection opening exposing the second through via conductive pattern;

a planarized film on the protective film, and including a second pad connection opening exposing the second through via conductive pattern;

a color filter on the planarized film and overlapping each of the photoelectric conversion devices in the pixel area; and

a microlens on the color filter.

13. The image sensor according to claim 10, further comprising:

a protective film conformal with the anti-reflective layer, the device isolation structure, the voltage connection structure, and the through via structure, and including a first pad connection opening exposing the second through via conductive pattern and a first voltage connection opening exposing the second voltage connection conductive pattern;

a planarized film on the protective film, and including a second pad connection opening exposing the second through via conductive pattern and a second voltage connection opening exposing the second voltage connection conductive pattern;

a color filter on the planarized film and overlapping each of the photoelectric conversion devices in the pixel area; and

a microlens on the color filter.

14. An image sensor, comprising:

a semiconductor substrate including a pixel area, a voltage connection area, and a pad area;

a plurality of photoelectric conversion devices in the pixel area;

a device isolation structure between the plurality of photoelectric conversion devices, from a front side toward a back side of the semiconductor substrate;

at least one voltage applying device configured to apply a voltage to the device isolation structure;

an insulating layer on the front side of the semiconductor substrate; and

an internal circuit in the insulating layer, and including a plurality of conductive inner wires and a plurality of inner vias in the voltage connection area and the pad area, respectively,

wherein the internal circuit is electrically connected to the device isolation structure and the at least one voltage applying device through the plurality of inner wires and the plurality of inner vias in the insulating layer.

15. The image sensor according to claim 14, wherein the device isolation structure comprises:

a device isolation trench projecting into at least a portion of the semiconductor substrate from the front side of the semiconductor substrate toward the back side;

a device isolation pattern conformal with an inner wall of the device isolation trench; and

a device isolation conductive pattern inside the device isolation trench on the device isolation pattern,

wherein a front end of the device isolation structure is coplanar with the front side of the semiconductor substrate.

16. An image sensor, comprising:

a semiconductor substrate including a pixel area, a voltage connection area, and a pad area;

a plurality of photoelectric conversion devices in the pixel area;

a device isolation structure between the plurality of photoelectric conversion devices;

at least one voltage applying device in the voltage connection area configured to apply a voltage to the device isolation structure;

an internal circuit including a plurality of conductive inner wires and a plurality of conductive inner vias in the voltage connection area and in the pad area, respectively.

17. The image sensor of claim 16, further comprising:

an anti-reflective layer on a back side of the semiconductor substrate and on the plurality of photoelectric conversion devices.

18. The image sensor of claim 16, further comprising:

at least one voltage connection structure in the voltage connection area, and electrically connected to the device isolation structure and to the at least one voltage applying device.

19. The image sensor of claim 16, further comprising:

an insulating layer on the front side of the semiconductor substrate.

20. The image sensor of claim 19, wherein the internal circuit is in the insulating layer.