Varied STI Liners for Isolation Structures in Image Sensing Devices

• US 20150279879A1
• Filed: 04/13/2015
• Published: 10/01/2015
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chou, Cheng-Hsien, Tsai, Chia-Shiung, Hung, Feng-Chi, Lu, Jiech-Fun, Kao, Min-Feng, Chou, Shih Pei, Tu, Yeur-Luen
• Granted Patent: US 10,008,531 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/76229 Concurrent filling of a plurality of trenches having a different trench shape or dimension, e.g. rectangular and V-shaped trenches, wide and narrow trenches, shallow and deep trenches
• CPC Class Codes: H01L 21/76237 introducing impurities in trench side or bottom walls, e.g. for forming channel stoppers or alter isolation behavior
• 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 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 29/0649 Dielectric regions, e.g. SiO2 regions, air gaps

Abstract

An integrated circuit device incorporating a plurality of isolation trench structures configured for disparate applications and a method of forming the integrated circuit are disclosed. In an exemplary embodiment, a substrate having a first region and a second region is received. A first isolation trench is formed in the first region, and a second isolation trench is formed in the second region. A first liner layer is formed in the first isolation trench, and a second liner layer is formed in the second isolation trench. The second liner layer has a physical characteristic that is different from a corresponding physical characteristic of the first liner layer. An implantation procedure is performed on the second isolation trench and the second liner layer formed therein. The physical characteristic of the second liner layer may be selected to enhance an implantation depth or an implantation uniformity compared to the first liner layer.

Claims

1. An integrated circuit device comprising:

a substrate having;

a sensor element and a circuit element formed thereupon;

a first isolation structure formed thereupon,

wherein the first isolation structure includes a first liner layer and a first trench fill material, and

wherein the first isolation structure is disposed adjacent to the circuit element; and

a second isolation structure formed thereupon,

wherein the second isolation structure includes a second liner layer and a second trench fill material,

wherein the second isolation structure is disposed adjacent to the sensor element, and

wherein the first liner layer is different from the second liner layer.

2. The device of claim 1, wherein the second isolation structure further includes a junction isolation implantation region.

3. The device of claim 1, wherein the second liner layer has a thickness that is less than a thickness of the first liner layer.

4. The device of claim 3, wherein the thickness of the second liner layer is less than about 100 Angstroms.

5. The device of claim 4, wherein the thickness of the first liner layer is greater than or equal to about 100 Angstroms.

6. The device of claim 1, wherein a portion of the substrate adjacent to the second isolation structure includes a dopant, and wherein a portion of the substrate adjacent to the first isolation structure is free of the dopant.

7. An integrated circuit device comprising:

a sensor portion including a first isolation structure including a first liner disposed on a doped portion of a substrate; and

a circuit portion including a second isolation structure including a second liner disposed on an undoped portion of the substrate.

8. The integrated circuit device of claim 7, wherein a thickness of the first liner is different from a thickness of the second liner.

9. The integrated circuit device of claim 8, wherein the thickness of the first liner is less than the thickness of the second liner.

10. The integrated circuit device of claim 9, wherein the thickness of the first liner is less than about 100 Angstroms, and wherein the thickness of the second liner is greater than or equal to about 100 Angstroms.

11. The integrated circuit device of claim 7, wherein a depth of the first isolation structure is different from a depth of the second isolation structure.

12. The integrated circuit device of claim 11, wherein the first isolation structure is a deep trench isolation structure.

13. The integrated circuit device of claim 11, wherein the depth of the first isolation structure is less than or equal to about 1500 Angstroms, and wherein the depth of the second isolation structure is between about 2500 Angstroms and about 3000 Angstroms.

14. The integrated circuit device of claim 7, wherein the doped portion of the substrate includes a boron dopant.

15. A device comprising:

a substrate having a first portion associated with an image sensor and a second portion associated with a circuit element,

wherein the first portion includes a first isolation structure including a first liner disposed on a doped portion of the substrate,

wherein the second portion includes a second isolation structure including a second liner disposed on an undoped portion of the substrate, and

wherein the first liner has a different thickness than the second liner.

16. The device of claim 15, wherein the first liner is thinner than the second liner.

17. The device of claim 15, wherein the first liner is less than about 100 Angstroms thick, and wherein the second liner is greater than or equal to about 100 Angstroms thick.

18. The device of claim 15, wherein the doped portion of the substrate includes boron, and wherein the undoped portion of the substrate is free of boron.

19. The device of claim 15, wherein a depth of the first isolation structure is different from a depth of the second isolation structure.

20. The device of claim 15, wherein the first isolation structure is a deep trench isolation structure.