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

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.