Integrated bio-sensor with nanocavity and fabrication method thereof

Patent metadata

Field	Value
Publication number	US-9842870-B2
Application number	US-201715613148-A
Country	US
Kind code	B2
Filing date	Jun 3, 2017
Priority date	Jul 15, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A bio-sensor includes a substrate having a light-sensing region thereon. A first dielectric layer, a diffusion barrier layer, and a second dielectric layer are disposed on the substrate. A trenched recess structure is formed in the second dielectric layer, which is filled with a light filter layer that is capped with a cap layer. A first passivation layer and a nanocavity construction layer are disposed on the cap layer. A nanocavity is formed in the nanocavity construction layer. The sidewall and bottom surface of the nanocavity is lined with a second passivation layer.

First claim

What is claimed is:

1. An integrated bio-sensor with a nanocavity, comprising:
a substrate, wherein a plurality of isolation structures is disposed on the substrate, and wherein a plurality of pixel regions is defined by the isolation structures;
a light-sensing region disposed in each of the pixel regions;
a first dielectric layer disposed on the substrate;
a trenched recess structure disposed in the first dielectric layer and corresponding to the light-sensing region;
a liner layer disposed conformally on an inner wall of the trenched recess structure;
a light filter layer disposed on the liner layer in the trenched recess structure, wherein the light filter layer has a top surface, and the top surface of the light filter layer is lower than a top surface of the first dielectric layer by a predetermined depth for forming a recess part;
a cap layer disposed conformally on the trenched recess structure and directly contacting the top surface of the light filter layer; and
a passivation layer disposed conformally on the cap layer, wherein a nanocavity is formed above the recess part by the cap layer and the passivation layer together.

2. The integrated bio-sensor with the nanocavity of claim 1 , wherein the substrate comprises a silicon substrate.

3. The integrated bio-sensor with the nanocavity of claim 1 , wherein the light-sensing region comprises a photodiode.

4. The integrated bio-sensor with the nanocavity of claim 1 , further comprising a second dielectric layer disposed between the substrate and the first dielectric layer, wherein a bottom part of the trenched recess structure is a top surface of the second dielectric layer.

5. The integrated bio-sensor with the nanocavity of claim 1 , wherein the light filter layer comprises metal ions.

6. The integrated bio-sensor with the nanocavity of claim 5 , wherein the metal ions comprise a sodium ion.

7. The integrated bio-sensor with the nanocavity of claim 1 , wherein the liner layer comprises a silicon nitride layer.

8. The integrated bio-sensor with the nanocavity of claim 1 , wherein the first dielectric layer comprises a silicon oxide layer.

9. The integrated bio-sensor with the nanocavity of claim 4 , wherein the second dielectric layer comprises a silicon nitride layer.

10. The integrated bio-sensor with the nanocavity of claim 1 , wherein the passivation layer comprises metal oxide.

11. The integrated bio-sensor with the nanocavity of claim 10 , wherein the metal oxide comprises tantalum oxide.

12. A fabrication method of an integrated bio-sensor with a nanocavity, comprising:
providing a substrate, wherein a plurality of isolation structures are disposed on the substrate, and a plurality of pixel regions are defined by the isolation structures;
forming a light-sensing region in each of the pixel regions;
depositing a first dielectric layer on the substrate;
forming a trenched recess structure in the first dielectric layer corresponding to the light-sensing region;
depositing a liner layer conformally on an inner wall of the trenched recess structure;
forming a light filter layer on the liner layer, wherein the trenched recess structure is filled with the light filter layer;
performing an etching back process so as to make a top surface of the light filter lower than a top surface of the first dielectric layer by a predetermined depth for forming a recess part;
depositing a cap layer conformally on the trenched recess structure, wherein the cap layer directly contacts the top surface of the light filter layer; and
forming a passivation layer conformally on the cap layer, wherein a nanocavity is formed above the recess part by the cap layer and the passivation layer together.

13. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the passivation layer is formed by physical vapor deposition process.

14. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the passivation layer comprises metal oxide.

15. The fabrication method of the integrated bio-sensor with the nanocavity of claim 14 , wherein the metal oxide comprises tantalum oxide.

16. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein after the step of forming the light filter layer, the fabrication method further comprises:
performing a solidification process for solidifying the light filter layer; and
performing a polishing process or an etching back process for removing the light filter layer outside the trenched recess structure.

17. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the substrate comprises a silicon substrate.

18. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the light-sensing region comprises a photodiode.

19. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the step of forming the trenched recess structure comprises:
forming a second dielectric layer and the first dielectric layer sequentially on the substrate; and
performing an etching process to remove a part of the first dielectric layer, wherein the second dielectric layer is configured to be an etching stop layer in the etching process.

20. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the light filter layer comprises metal ions.

21. The fabrication method of the integrated bio-sensor with the nanocavity of claim 20 , wherein the metal ions comprise a sodium ion.

22. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the liner layer comprises a silicon nitride layer.

23. The fabrication method of the integrated bio-sensor with the nanocavity of claim 12 , wherein the first dielectric layer comprises a silicon oxide layer.

24. The fabrication method of the integrated bio-sensor with the nanocavity of claim 19 , wherein the second dielectric layer comprises a silicon nitride.

Assignees

• Powerchip Technology Corp

Inventors

• Chung Tse-Wei
• Chou Tsung-Hui
• Lin Che-Hung
• Lu shao-wei
• Lin Hsiao-Pei

Classifications

• G01N2021/6482

  Sample cells, cuvettes · CPC title

• G01N21/6454

  using an integrated detector array · CPC title

• H01L27/14645

  Electricity · mapped topic

• H01L31/02162

  Electricity · mapped topic

• H01L27/14643

  Electricity · mapped topic