Method of preparing self-aligned isolation regions between sensor elements

Patent metadata

Field	Value
Publication number	US-9401384-B2
Application number	US-201514877986-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Aug 30, 2010
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

A method of preparing self-aligned isolation regions between two neighboring sensor elements on a substrate includes patterning an oxide layer to form an opening between the two neighboring sensor elements on the substrate. The method further includes performing a first implant to form a deep doped region between the two neighboring sensor elements, wherein a top portion of the deep doped region is below a top surface of the substrate. The method further includes performing a second implant to form a shallow doped region between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with the top portion of the deep doped region.

First claim

What is claimed is:

1. A method of preparing self-aligned isolation regions between two neighboring sensor elements on a substrate, the method comprising:
patterning an oxide layer to form an opening between the two neighboring sensor elements on the substrate;
performing a first implant to form a deep doped region between the two neighboring sensor elements, wherein a top portion of the deep doped region is below a top surface of the substrate; and
performing a second implant to form a shallow doped region between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with the top portion of the deep doped region.

2. The method of claim 1 , wherein performing the second implant comprises decreasing a size of the two neighboring sensor elements.

3. The method of claim 1 , further comprising removing the oxide layer after the second implant.

4. The method of claim 1 , further comprising forming a shallow isolation feature in the substrate between the two neighboring sensor elements, wherein the shallow isolation feature is formed prior to the first implant.

5. The method of claim 1 , wherein patterning the oxide layer comprises exposing a portion of the two neighboring sensor elements.

6. The method of claim 1 , further comprising depositing a conformal dielectric layer over the patterned oxide layer.

7. The method of claim 6 , wherein performing the second implant comprises performing the second implant through the conformal dielectric layer.

8. The method of claim 1 , further comprising forming an etch stop layer between the substrate and the oxide layer.

9. The method of claim 8 , wherein performing the first implant comprises performing the first implant through the etch stop layer.

10. The method of claim 8 , wherein performing the second implant comprises performing the second implant through the etch stop layer.

11. A method of preparing self-aligned isolation regions between two neighboring sensor elements on a substrate, the method comprising:
patterning an oxide layer to form an opening between the two neighboring sensor elements on the substrate;
performing a first implant to form a deep doped region below the two neighboring sensor elements, wherein a top portion of the deep doped region is below a top surface of the substrate;
reducing a width of the opening; and
performing a second implant through the opening having the reduced width to form a shallow doped region between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with the top portion of the deep doped region.

12. The method of claim 11 , further comprising forming a shallow trench isolation (STI)in the substrate between the two neighboring sensor elements.

13. The method of claim 11 , wherein performing the first implant comprises implanting dopants having a different dopant type from a dopant type of the two neighboring sensor elements.

14. The method of claim 11 , wherein reducing the opening comprises depositing a conformal layer over the oxide layer.

15. The method of claim 14 , wherein performing the second implant comprises performing the second implant through the STI.

16. A method of preparing self-aligned isolation regions between two neighboring sensor elements on a substrate, the method comprising:
patterning an oxide layer to form an opening between the two neighboring sensor elements on the substrate;
performing a first implant to form a deep doped region below the two neighboring sensor elements, wherein a top portion of the deep doped region is below a top surface of the substrate;
forming a shallow trench isolation (STI) in the substrate between the neighboring sensor elements; and
performing a second implant to form a shallow doped region between the two neighboring sensor elements, wherein a bottom portion of the shallow doped region overlaps with the top portion of the deep doped region.

17. The method of claim 16 , wherein performing the first implant comprises performing the first implant through the STI.

18. The method of claim 16 , wherein performing the second implant comprises performing the second implant through the STI.

19. The method of claim 16 , wherein performing the second implant comprises forming the shallow doped region having a width different from a width of the deep doped region.

20. The method of claim 16 , wherein performing the second implant comprises forming the shallow doped region having a width equal to a width of the deep doped region.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Fu Shih-Chi
• Tzeng Kai
• Lu Wen-Chen

Classifications

• H10W10/0148 Primary

  comprising introducing impurities in side walls or bottom walls of trenches, e.g. for forming channel stoppers · CPC title

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F39/807

  Pixel isolation structures · CPC title

• H10F39/194

  having arrangements for blooming suppression · CPC title