Isolation structures for preventing photons and carriers from reaching active areas and methods of formation
First Claim
1. 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, and wherein the trench structure prevents at least a portion of photons or charged particles from passing through the trench structure to the array wherein said trench structure has a top width and a base layer width and the base layer width is smaller than the top width wherein the trench structure 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.
2 Assignments
0 Petitions
Accused Products
Abstract
Regions of an integrated circuit are isolated by a structure that includes at least one isolating trench on the periphery of an active area. The trench is deep, extending at least about 0.5 μm into the substrate. The isolating structure prevents photons and electrons originating in peripheral circuitry from reaching the active area. Where the substrate has a heavily-doped lower layer and an upper layer on it, the trench can extend through the upper layer to the lower layer. A thermal oxide can be grown on the trench walls. A liner can also be deposited on the sidewalls of each trench. A fill material having a high-extinction coefficient is then deposited over the liner. The liner can also be light absorbent so that both the liner and fill material block photons.
62 Citations
57 Claims
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1. An integrated circuit comprising:
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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, and wherein the trench structure prevents at least a portion of photons or charged particles from passing through the trench structure to the array wherein said trench structure has a top width and a base layer width and the base layer width is smaller than the top width wherein the trench structure 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A structure for isolating an active area of an integrated circuit, the structure comprising:
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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. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. 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 where at least one trench of the plurality of trenches includes a top width and a base layer width where the base layer width is smaller than the top width further comprising an insulating liner formed along each sidewall of the plurality of trenches wherein the insulating liner comprises a high absorption material. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A processing system, the processing system comprising:
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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. - View Dependent Claims (37, 38, 39, 40)
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41. An isolation structure provided at a surface of a substrate between a source area in which at least one of photons and charged particles originate and an active region, the isolation structure comprising:
at least one trench extending from the surface of the substrate into the substrate to a depth of at least about 0.5 μ
m and with a length extending across the surface of the substrate between the source area and the active area and the at least one trench includes a top width and a base layer width where the base layer width is smaller than the top width.
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42. An integrated circuit comprising:
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a substrate; an array of pixel cells at a surface of the substrate, each pixel cell comprising a photo-conversion device; and at least one trench around at least a portion of the array, wherein the trench extends from the surface of the substrate to a depth of at least about 0.5 μ
m into the substrate and the at least one trench includes a top width and a base layer width where the base layer width is smaller than the top width wherein the at least one trench structure has sidewalls and contains a first material that prevents a portion of photons or charged particles from passing through the trench structure to the array.
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43. A processing system, the processing system comprising:
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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 extending from a surface of a substrate to a depth of at least about 0.5 μ
m into the substrate and the trench includes a top width and a base layer width where the base layer width is smaller than the top width.
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44. An integrated circuit comprising:
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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. - View Dependent Claims (45, 46, 47)
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48. A structure for isolating an active area of an integrated circuit, the structure comprising:
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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. - View Dependent Claims (49, 50, 51)
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52. 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 wherein the first fill material is a high extinction coefficient material.
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53. A structure for isolating an active area on an integrated circuit, the structure comprising:
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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. - View Dependent Claims (54, 55, 56, 57)
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Specification