Alignment marks in substrate having through-substrate via (TSV)
First Claim
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1. A method comprising:
- performing a backside grinding on a substrate to expose an alignment through-substrate via (TSV) and a function TSV, wherein a back surface of the substrate is exposed after the backside grinding, the alignment TSV formed from three or more straight conductive segments in a plan view;
forming a passivation layer contacting the back surface, wherein the passivation layer is formed as a blanket layer, and wherein the alignment and the functional TSVs penetrate through the passivation layer; and
forming a conductive feature on a backside of the substrate, wherein the conductive feature is electrically coupled to the functional TSV, and the forming the conductive feature is performed using the alignment TSV as an alignment mark, wherein the alignment TSV and the functional TSV are a same width.
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Abstract
A device includes a substrate, and an alignment mark including a conductive through-substrate via (TSV) penetrating through the substrate.
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Citations
19 Claims
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1. A method comprising:
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performing a backside grinding on a substrate to expose an alignment through-substrate via (TSV) and a function TSV, wherein a back surface of the substrate is exposed after the backside grinding, the alignment TSV formed from three or more straight conductive segments in a plan view; forming a passivation layer contacting the back surface, wherein the passivation layer is formed as a blanket layer, and wherein the alignment and the functional TSVs penetrate through the passivation layer; and forming a conductive feature on a backside of the substrate, wherein the conductive feature is electrically coupled to the functional TSV, and the forming the conductive feature is performed using the alignment TSV as an alignment mark, wherein the alignment TSV and the functional TSV are a same width. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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forming a first conductive through-substrate via (TSV) and a second conductive TSV in a substrate, the substrate having a front side and a backside, the first conductive TSV having a first width in a direction parallel to the backside, the second TSV having a second width in the direction parallel to the backside, the second width equal to the first width; forming an interconnect structure on the front side of the substrate, wherein the second TSV in the substrate is electrically coupled to metal lines and vias in the interconnect structure, and no metal line and via in the interconnect structure is electrically coupled to the first conductive TSV in the substrate; performing a backside grinding on the substrate to expose the first conductive TSV and the second conductive TSV, wherein the backside grinding is performed from the backside of the substrate; forming a passivation layer over a back surface of the substrate, the first conductive TSV and the second conductive TSV penetrating through the passivation layer; forming an under-bump metallurgy (UBM) layer on the passivation layer, the UBM layer being over the back surface of the substrate, the first conductive TSV, and the second conductive TSV; forming a conductive feature on the UBM layer, wherein the conductive feature is electrically coupled to the second conductive TSV, and wherein when the conductive feature is formed, a position of the conductive feature is determined using the first conductive TSV that penetrates through the passivation layer as an alignment mark, and wherein no conductive feature is formed to connect to the first conductive TSV; and removing portions of the UBM layer over the first conductive TSV and the back surface of the substrate. - View Dependent Claims (10, 11, 12, 13)
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14. A method comprising:
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simultaneously forming a group of alignment through-substrate vias (TSVs) and a group of functional TSVs in a substrate, the group of alignment TSVs arranged in a rectangular region substantially free of each of the group of functional TSVs, each of the group of functional TSVs electrically coupling first conductive features on a back surface of the substrate to second conductive features on a front surface of the substrate; performing a backside grinding from a backside of the substrate, wherein the group of alignment TSVs and the group of functional TSVs are exposed through the back surface of the substrate; after the backside grinding, recessing the back surface of the substrate to allow the group of alignment TSVs and the group of functional TSVs to protrude beyond the back surface, wherein a space is left by an etched back surface layer of the substrate removed in the recessing; forming a passivation layer on the back surface of the substrate, wherein the passivation layer is filled into the space; removing portions of the passivation layer that overlap the group of alignment TSVs to expose the group of alignment TSVs; and with the passivation layer covering the back surface of the substrate, forming the first conductive features on the back surface of the substrate and electrically coupled to at least one TSV of the group of functional TSVs, with the group of alignment TSVs used as an alignment mark for positioning the first conductive features. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification