Image sensor and method for fabricating the same

• US 10,373,997 B2
• Filed: 08/02/2017
• Issued: 08/06/2019
• Est. Priority Date: 02/01/2017
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Sung Soo, Lee, Kyung Ho
• Primary Examiner(s): Toledo, Fernando L
• Assistant Examiner(s): Prasad, Neil R
• Application Number:
  US15/666,907
• Publication Number:
  US 20180219040A1
• Time in Patent Office: 734 Days
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/02161 for devices characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/02162 for filtering or shielding light, e.g. multicolour filters for photodetectors
• 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
• CPC Class Codes: H01L 31/062 the potential barriers being only of the metal-insulator-semiconductor type
• CPC Class Codes: H01L 31/113 being of the conductor-insulator-semiconductor type, e.g. metal-insulator-semiconductor field-effect transistor
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

An image sensor and a method for fabricating the same are provided, in which the image sensor includes a substrate including a first sensing region having a photoelectric device therein, a boundary isolation film partitioning the first sensing region, an inner reflection pattern film within the substrate in the sensing region, an infrared filter on the substrate, and a micro lens on the infrared filter.

Claims

1. An image sensor, comprising:

a substrate including a first sensing region containing a photoelectric device therein, the substrate including a first surface and a second surface opposite to the first surface;

a boundary isolation trench connects the first surface and the second surface;

a boundary isolation film filling the boundary isolation trench;

an inner reflection pattern film within the substrate in the first sensing region;

a first fixed charge film including hafnium oxide on the boundary isolation film;

an infrared filter on the substrate;

a side anti-reflection film on the first fixed charge film and on a side surface of the infrared filter; and

a micro lens on the infrared filter.

2. The image sensor as claimed in claim 1, wherein:

the inner reflection pattern film is exposed from the second surface and not exposed from the first surface.

3. The image sensor as claimed in claim 1, wherein the boundary isolation film and the inner reflection pattern film include a first material which is identical.

4. The image sensor as claimed in claim 3, wherein the first material is at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film.

5. The image sensor as claimed in claim 1, wherein the inner reflection pattern film is spaced apart from the boundary isolation film.

6. The image sensor as claimed in claim 1, further comprising an anti-reflection film formed on a lateral surface of the infrared filter.

7. The image sensor as claimed in claim 6, wherein the anti-reflection film and the boundary isolation film overlap each other.

8. The image sensor as claimed in claim 1, further comprising a planarizing film under the micro lens.

9. The image sensor as claimed in claim 8, wherein the planarizing film is between the micro lens and the infrared filter and/or between the infrared filter and the substrate.

10. An image sensor, comprising:

a substrate including first and second sensing regions each containing a photoelectric device therein;

a boundary isolation film defining a boundary of the first and second sensing regions;

an inner reflection pattern film within the substrate in the second sensing region;

a first filter on the first sensing region of the substrate, wherein light transmitted by the first filter is directly incident on the photoelectric device in the first sensing region;

a second filter on the second sensing region of the substrate, wherein the second filter is different from the first filter, wherein light transmitted by the second filter is reflected by the inner reflection pattern film before being incident on the photoelectric device in the second sensing region;

a first micro lens on the first filter; and

a second micro lens on the second filter.

11. The image sensor as claimed in claim 10, wherein the second filter is an infrared filter.

12. The image sensor as claimed in claim 11, wherein the first filter is at least one of a red color filter, a green color filter, and a blue color filter.

13. The image sensor as claimed in claim 10, wherein the second filter simultaneously filters red light and infrared light.

14. The image sensor as claimed in claim 10, wherein:

the substrate includes third and fourth sensing regions,

the first and second sensing regions are in contact with the third and fourth sensing regions in a first direction, respectively,

the first and third sensing regions and the second and fourth sensing regions are in contact with each other in a second direction, intersecting the first direction, respectively, and

the image sensor further includes third and fourth filters on the third and fourth sensing regions, respectively.

15. The image sensor as claimed in claim 14, wherein:

the first, third and fourth filters are any one of a red color filter, a blue color filter, and a green color filter, and

the second filter is an infrared filter.

16. The image sensor as claimed in claim 14, wherein:

the third filter is a blue color filter,

the first and fourth filters are green color filters, and

the second filter is an infrared/red color filter.

17. The image sensor as claimed in claim 10, further including a sub-boundary isolation film to partition the first sensing region into at least two sub regions.

18. The image sensor as claimed in claim 17, wherein a plane shape of the inner reflection pattern film is different from a plane shape of the sub-boundary isolation film.

19. An image sensor, comprising:

a substrate including first and second surfaces opposite each other, and a first sensing region containing a photoelectric device therein;

an insulating structure on the first surface and including a wire structure;

a boundary isolation film on the second surface and extending into the substrate and defining the first sensing region;

an inner reflection pattern film within the first sensing region and extending into the substrate, and including a same material as the boundary isolation film;

a filter on the second surface to transmit only light of a certain wavelength, the inner reflection pattern film increasing an area in which light of the certain wavelength penetrates the first sensing region; and

a micro lens on the filter.