Image sensor having metal contact coupled through a contact etch stop layer with an isolation region

1. An image sensor pixel, comprising:

one or more photodiodes disposed in a semiconductor layer;

pixel circuitry disposed in the semiconductor layer coupled to the one or more photodiodes;

a passivation layer disposed proximate to the semiconductor layer over the pixel circuitry and the one or more photodiodes;

a single contact etch stop layer disposed over the passivation layer, wherein the single contact etch stop layer defines one or more isolation regions, wherein there is an absence of material of the single contact etch stop layer in the one or more isolation regions defined in the single contact etch stop layer;

one or more metal contacts coupled to the pixel circuitry through a first portion of the single contact etch stop layer, wherein a second portion of the single contact etch stop layer is disposed in a photodiode region of the one or more photodiodes,

wherein the one or more isolation regions defined in the single contact etch stop layer isolate the first portion of the single contact etch stop layer from the second portion of the single contact etch stop layer.

2. The image sensor pixel of claim 1 wherein the one or more isolation regions defined in the single contact etch stop layer substantially eliminate stress paths in the single contact etch stop layer between the first portion of the single contact etch stop layer and the second portion of the single etch stop layer.

3. The image sensor pixel of claim 1 wherein the one or more isolation regions are defined in the single contact etch stop layer where the material of the single contact etch stop layer is removed between the first portion of the single contact etch stop layer and the second portion of the single etch stop layer.

4. The image sensor pixel of claim 1 wherein the one or more metal contacts comprise borderless contacts.

5. The image sensor pixel of claim 1 wherein the single contact etch stop layer comprises nitride.

6. The image sensor pixel of claim 1 wherein the single contact etch stop layer comprises silicon oxynitride.

7. The image sensor pixel of claim 1 wherein the passivation layer comprises oxide.

8. The image sensor pixel of claim 1 further comprising a dielectric layer disposed over the single contact etch stop layer.

9. The image sensor pixel of claim 8 wherein the dielectric layer comprises borophosphosilicate glass.

10. The image sensor pixel of claim 1 wherein the image sensor pixel is comprised in a complementary metal oxide semiconductor (CMOS) image sensor.

11. An imaging system, comprising:

a pixel array of image sensor pixels, wherein each one of the image sensor pixels includes:

one or more photodiodes disposed in a semiconductor layer;

pixel circuitry disposed in the semiconductor layer coupled to the one or more photodiodes;

a passivation layer disposed proximate to the semiconductor layer over the pixel circuitry and the one or more photodiodes;

a single contact etch stop layer disposed over the passivation layer, wherein the single contact etch stop layer defines one or more isolation regions, wherein there is an absence of material of the single contact etch stop layer in the one or more isolation regions defined in the single contact etch stop layer;

one or more metal contacts coupled to the pixel circuitry through a first portion of the single contact etch stop layer, wherein a second portion of the single contact etch stop layer is disposed in a photodiode region of the one or more photodiodes,

wherein the one or more isolation regions defined in the single contact etch stop layer isolate the first portion of the single contact etch stop layer from the second portion of the single contact etch stop layer;

control circuitry coupled to the pixel array to control operation of the pixel array; and

readout circuitry coupled to the pixel array to readout image data from the plurality of pixels.

12. The imaging system of claim 11 further comprising function logic coupled to the readout circuitry to store the image data readout from the image sensor pixels.

13. The imaging system of claim 11 wherein the one or more isolation regions defined in the single contact etch stop layer substantially eliminate stress paths in the single contact etch stop layer between the first portion of the single contact etch stop layer and the second portion of the single etch stop layer.

14. The imaging system of claim 11 wherein the one or more isolation regions are defined in the single contact etch stop layer where the material of the single contact etch stop layer is removed between the first portion of the single contact etch stop layer and the second portion of the single etch stop layer.

15. The imaging system of claim 11 wherein the one or more metal contacts comprise borderless contacts.

16. The imaging system of claim 11 wherein the single contact etch stop layer comprises nitride.

17. The imaging system of claim 11 wherein the single contact etch stop layer comprises silicon oxynitride.

18. The imaging system of claim 11 wherein the passivation layer comprises oxide.

19. The imaging system of claim 11 further comprising a dielectric layer disposed over the single contact etch stop layer.

20. The imaging system of claim 19 wherein the dielectric layer comprises borophosphosilicate glass.

21. The imaging system of claim 11 wherein the image sensor pixel is comprised in a complementary metal oxide semiconductor (CMOS) image sensor.