Back-side illuminated (bsi) image sensor with global shutter scheme

A method of forming an image sensor, comprising:

• forming an image sensing element within a substrate
• forming a memory node within the substrate, wherein the memory node is laterally separated from the image sensing element;
• forming a masking layer along a back-side of the substrate over the image sensing element;
• etching the back-side of the substrate according to the masking layer to define one or more trenches directly between the memory node and a horizontal plane extending along the back-side of the substrate;
• and
• forming a reflective material within the one or more trenches.

A method of forming a back-side illuminated (BSI) image sensor, comprising:

• forming an image sensing element within a substrate;
• forming a memory node at a position within the substrate separated from the image sensing element;
• forming a dielectric structure surrounding one or more interconnect layers on a first side of the substrate;
• and
• forming a reflective material along a second side of the substrate facing an opposite direction as the first side, wherein the reflective material has sidewalls defining an aperture that is directly over the image sensing element.