Method of forming deep trench isolation in radiation sensing substrate and image sensor device
A method of forming a deep trench isolation in a radiation sensing substrate includes: forming a trench in the radiation sensing substrate; forming a corrosion resistive layer in the trench, in which the corrosion resistive layer includes titanium carbon nitride having a chemical formula of TiC x N (2-x) , and x is in a range of 0.1 to 0.9; and filling a reflective material in the trench and over the corrosion resistive layer.
1. An image sensor device, comprising:
a radiation sensing substrate having a front surface and a back surface; and
a deep trench isolation in the radiation sensing substrate, the deep trench isolation comprising:
a trench extending from the back surface into the radiation sensing substrate; and
a corrosion resistive layer in the trench, wherein the corrosion resistive layer is a titanium carbon nitride layer.
2. The image sensor device of claim 1 , wherein titanium carbon nitride of the titanium carbon nitride layer has a chemical formula of TiC x N (2-x) , and x is in a range of 0.1 to 0.9.
3. The image sensor device of claim 2 , wherein x is in a range of 0.2 to 0.8.
4. The image sensor device of claim 1 , wherein the titanium carbon nitride layer comprises 15 to 40 at % of carbon.
5. The image sensor device of claim 1 , wherein the titanium carbon nitride layer comprises 15 to 40 at % of nitrogen.
6. The image sensor device of claim 1 , wherein in the titanium carbon nitride layer, a difference between an amount of carbon and an amount of nitrogen is lower than or equal to 10 at %.
7. The image sensor device of claim 1 , wherein in the titanium carbon nitride layer, an amount of titanium is greater than an amount of nitrogen.
8. The image sensor device of claim 1 , wherein in the titanium carbon nitride layer, an amount of nitrogen is greater than an amount of carbon.
9. The image sensor device of claim 1 , wherein the deep trench isolation further comprises a dielectric material between the corrosion resistive layer and an interior surface of the trench.
10. The image sensor device of claim 1 , wherein the deep trench isolation further comprises a reflective material in the trench and over the corrosion resistive layer.
11. The image sensor device of claim 10 , wherein the reflective material comprises tungsten.
12. The image sensor device of claim 10 , wherein the corrosion resistive layer is disposed in the trench is in a conformal manner, and the reflective material fills the trench.
13. The image sensor device of claim 10 , wherein the reflective material is in contact with the corrosion resistive layer.
14. An image sensor device, comprising:
a radiation sensing substrate having a front surface and a back surface, wherein a trench is defined by the radiation sensing substrate and extends from the back surface into the radiation sensing substrate;
a first dielectric layer in the trench; and
a corrosion resistive layer in the trench, wherein:
the corrosion resistive layer is a titanium carbon nitride layer, and
the first dielectric layer is disposed between a sidewall of the radiation sensing substrate defining the trench and a sidewall of the corrosion resistive layer.
15. The image sensor device of claim 14 , further comprising:
a second dielectric layer overlying the radiation sensing substrate, the first dielectric layer, and the corrosion resistive layer.
16. The image sensor device of claim 15 , wherein the second dielectric layer is in contact with a top surface of the corrosion resistive layer and a top surface of the first dielectric layer.
17. The image sensor device of claim 15 , further comprising:
a reflective element overlying the second dielectric layer and at least partially overlying the corrosion resistive layer.
18. The image sensor device of claim 14 , further comprising:
a reflective element at least partially overlying the corrosion resistive layer.
19. The image sensor device of claim 14 , further comprising:
a reflective material in the trench, wherein the corrosion resistive layer is between the first dielectric layer and the reflective material.
20. An image sensor device, comprising:
a radiation sensing substrate having a front surface and a back surface, wherein a trench is defined by the radiation sensing substrate and extends from the back surface into the radiation sensing substrate;
a first dielectric layer in the trench;
a corrosion resistive layer in the trench, wherein:
the corrosion resistive layer is a titanium carbon nitride layer, and
the first dielectric layer is disposed between a sidewall of the radiation sensing substrate defining the trench and a sidewall of the corrosion resistive layer;
a reflective material in the trench, wherein the corrosion resistive layer is between the first dielectric layer and the reflective material; and
a second dielectric layer in contact with a top surface of the reflective material, a top surface of the corrosion resistive layer, and a top surface of the first dielectric layer.