Isolation structures for preventing photons and carriers from reaching active areas and methods of formation

A structure for isolating an active area of an integrated circuit, the structure comprising:

• a trench formed in a substrate of the integrated circuit along at least a portion of a periphery of the active area, the substrate having a lower layer and an upper layer on the lower layer, wherein the trench extends from a surface of the upper layer to a surface of the lower layer and the trench includes a top width and a base layer width where the base layer width is smaller than the top width;
• an insulating liner formed along sidewalls of the trench;
• and
• a first fill material formed over the insulating liner wherein the first fill material at least partially fills the trench and prevents at least a portion of photons and electrons from passing through the trench to the active area.

A processing system, the processing system comprising:

• a processor;
• an integrated circuit coupled to the processor, the integrated circuit comprising a structure for isolating an active area on the integrated circuit, the structure comprising:
• a trench formed in a substrate on at least a portion of a periphery of the active area of the integrated circuit, wherein the trench extends to a surface of a base layer below the substrate, and wherein the trench has sidewalls and the trench includes a top width and a base layer width where the base layer width is smaller than the top width;
• an insulating liner formed along the sidewalls;
• and
• a first fill material formed over the insulating liner that at least partially fills the trench and prevents at least a portion of photons or electrons from passing through the trench.

An integrated circuit comprising:

• a substrate comprising a lower layer and an upper layer on the lower layer;
• an array of pixel cells at a surface of the upper layer, each pixel cell comprising a photo-conversion device;
• and
• a trench structure around at least a portion of the array, wherein the trench structure:
• extends from the surface to the lower layer,
• prevents at least a portion of photons or charged particles from passing through the trench structure to the array;
• has sidewalls and contains a first material that prevents at least a portion of photons or charged particles from passing through the trench structure to the array;
• and
• contains a second material that partially fills the trench structure, wherein the second material prevents at least a portion of photons or charged particles from passing through the trench structure to the array.

A structure for isolating an active area of an integrated circuit, the structure comprising:

• a trench formed in a substrate of the integrated circuit along at least a portion of a periphery of the active area, the substrate having a lower layer and an upper layer on the lower layer, wherein the trench extends from a surface of the upper layer to a surface of the lower layer;
• an insulating liner formed along sidewalls of the trench;
• a first fill material formed over the insulating liner wherein the first fill material at least partially fills the trench and prevents at least a portion of photons and electrons from passing through the trench to the active area, and
• a second fill material that partially fills the trench, wherein the second material prevents at least a portion of photons from passing through the trench.

A structure for isolating an active area on an integrated circuit, the structure comprising:

• a plurality of trenches formed in a substrate of the integrated circuit on at least a portion of a periphery of the active area, wherein a depth of each of the plurality of trenches extends to a surface of a base layer of said substrate and the plurality of trenches include:
• a first fill material that at least partially fills each of the plurality of trenches and prevents at least a portion of photons or charged particles from passing through the trench;
• and
• a second fill material that partially fills each of the plurality of trenches, wherein the second material prevents at least a portion of photons from passing through the trench.