# US 2013/0157436 A1 · Forming through substrate vias > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157436 A1 - Document ID: US20130157436A1 - Status: Published application - Kind: A1 - Application number: 13/325,191 - Filed: 2011-12-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-14 - Assignees: Sematech, Inc. - Inventors: Klaus HUMMLER - Web page: https://patentgrep.com/patent/US20130157436A1 ## CPC - H10W 20/023: {the interconnections being through-semiconductor vias} - H10W 20/0245: {comprising use of blind vias during the manufacture} - H10W 20/0257: {comprising using a sacrificial placeholder, e.g. using a sacrificial plug} - H10W 20/20: Interconnections within wafers or substrates, e.g. through-silicon vias [TSV] - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A method is provided for establishing through substrate vias (TSVs) within a substrate. The method includes: forming at least one recess in a front-side of a wafer; filling, at least partially, the at least one recess with a sacrificial material from the front-side of the wafer; thinning the wafer from a back-side to reveal the at least one recess at least partially filled with the sacrificial material; removing from the back-side of the wafer the sacrificial material from the at least one recess; and filling the at least one recess from the back-side of the wafer with a conductive material to provide the at least one through substrate via. ## Claims ### Claim 1 A method comprising: providing at least one through substrate via (TSV) through a substrate, the providing comprising: forming at least one recess in a first side of a wafer; filling, at least partially, the at least one recess with a sacrificial material; thinning the wafer from a second side to reveal the at least one recess at least partially filled with the sacrificial material; removing, from the second side of the wafer, the sacrificial material from the at least one recess; and filling the at least one recess from the second side of the wafer with a conductive material to provide the at least one through substrate via. ### Claim 2 (depends on 1) The method of claim 1, wherein the first side is a front-side of the wafer and the second side is a back-side of the wafer, the front-side being an active device side of the wafer. ### Claim 3 (depends on 2) The method of claim 2, wherein the forming of the at least one recess, and the filling, at least partially, of the at least one recess with the sacrificial material, are performed prior to formation of one or more active devices in the front-side of the wafer, and the removing of the sacrificial material from the at least one recess and the filling of the at least one recess with the conductive material are performed after formation of the one or more active devices in the front-side of the wafer. ### Claim 4 (depends on 1) The method of claim 1, wherein the filling, at least partially, the at least one recess with the sacrificial material comprises establishing, during that filling, at least one fill void within the sacrificial material within the at least one recess. ### Claim 5 (depends on 4) The method of claim 4, wherein the establishing comprises controlling the filling, at least partially, of the at least one recess with the sacrificial material so that the at least one fill void is enclosed within the sacrificial material within the at least one recess. ### Claim 6 (depends on 1) The method of claim 1, further comprising, after the filling, at least partially, the at least one recess with the sacrificial material, and before the removing from the second side of the wafer the sacrificial material from the at least one recess, forming one or more conductive contacts for the at least one through substrate via, the one or more conductive contacts being formed at the first side of the wafer over the at last one recess with the sacrificial material and providing electrical contact to the conductive material once filled within the at least one recess from the second side of the wafer. ### Claim 7 (depends on 6) The method of claim 6, wherein the sacrificial material comprises polysilicon, and the method further comprises forming a silicide layer in the polysilicon at the first side of the wafer before forming the one or more conductive contacts for the at least one through substrate via, wherein the one or more conductive contacts formed for the at least one through substrate via electrically contact the silicide layer, and the removing comprises removing the polysilicon, from the second side of the wafer, from the at least one recess, leaving the silicide layer. ### Claim 8 (depends on 1) The method of claim 1, wherein filling the at least one recess from the second side of the wafer with the conductive material comprises utilizing a dual damascene process to fill the at least one recess from the second side of the wafer with the conductive material and concurrently form a second side, line-level metallization at the second side of the wafer. ### Claim 9 A method of forming a structure comprising: forming at least one recess in a front-side of a wafer; filling, at least partially, the at least one recess with a sacrificial material; forming one or more devices at the front-side of the wafer; thinning the wafer from a back-side to reveal the at least one recess at least partially filled with the sacrificial material, the thinning being subsequent to the forming of the one or more devices at the front-side of the wafer; removing, from the back-side of the wafer, the sacrificial material from the at least one recess; and filling the at least one recess from the back-side of the wafer with a conductive material to provide at least one through substrate via (TSV) through the wafer. ### Claim 10 (depends on 9) The method of claim 9, wherein forming the at least one recess in the front-side of the wafer comprises forming the at least one recess to extend a predetermined distance into the wafer from the front-side of the wafer. ### Claim 11 (depends on 10) The method of claim 10, wherein one recess of the at least one recess comprises substantially vertical side walls extending from the front-side into the wafer or re-entrant side walls which facilitate the subsequent filling of the at least one recess from the back-side of the wafer with the conductive material. ### Claim 12 (depends on 9) The method of claim 9, further comprises implementing the forming of the at least one recess in the front-side of the wafer, and the filling, at least partially, the at least one recess with the sacrificial material within a shallow trench isolation (STI) process module employed in forming the structure. ### Claim 13 (depends on 9) The method of claim 9, wherein prior to the filling, at least partially, the at least one recess with the sacrificial material, the method comprises depositing a dielectric liner within the at least one recess formed in the front-side of the wafer. ### Claim 14 (depends on 9) The method of claim 9, wherein the filling, at least partially, the at least one recess with the sacrificial material comprises establishing, during that filling, at least one fill void within the sacrificial material within the at least one recess. ### Claim 15 (depends on 14) The method of claim 14, wherein the establishing comprises controlling the filling, at least partially, of the at least one recess with the sacrificial material so that the at least one fill void is enclosed within the sacrificial material within the at least one recess. ### Claim 16 (depends on 14) The method of claim 14, wherein the filling, at least partially, the at least one recess with the sacrificial material comprises non-conformally filling, at least partially, the at least one recess with the sacrificial material so that the sacrificial material pinches together in an upper region of the at least one recess at the front-side of the wafer. ### Claim 17 (depends on 9) The method of claim 9, further comprising, after the filling, at least partially, the at least one recess with the sacrificial material, and after the forming one or more active devices at the front-side of the wafer, forming one or more conductive contacts at the front-side of the wafer over the at least one recess with the sacrificial material, the one or more conductive contacts providing electrical contact to the conductive material once filled within the at least one recess from the back-side of the wafer. ### Claim 18 (depends on 17) The method of claim 17, wherein the sacrificial material comprises polysilicon, and the method further comprises forming a silicide layer in the polysilicon at the front-side of the wafer before forming the one or more conductive contacts for the at least one through substrate via, wherein the one or more conductive contacts formed for the at least one through substrate via electrically contact the silicide layer, and the removing comprises removing the polysilicon, from the back-side of the wafer, from the at least one recess, leaving the silicide layer. ### Claim 19 (depends on 9) The method of claim 9, wherein filling the at least one recess from the back-side of the wafer with the conductive material comprises utilizing a dual damascene process to fill the at least one recess from the back-side of the wafer with a conductive material and concurrently form a back-side, line-level metallization at the back-side of the wafer. ### Claim 20 (depends on 19) The method of claim 19, wherein the conductive material comprises copper.