# US 2014/0196842 A1 · Method and device for permanent bonding of wafers, as well as cutting tool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196842 A1 - Document ID: US20140196842A1 - Status: Published application - Kind: A1 - Application number: 13/808,415 - Filed: 2012-01-23 - Published: 2014-07-17 - Earliest claimed: 2012-01-23 - Assignees: EV Group E. Thallner GmbH - Inventors: Klaus Martinschitz; Markus Wimplinger; Bernhard Rebhan - Web page: https://patentgrep.com/patent/US20140196842A1 ## CPC - B29C 65/74: by welding and severing {, or by joining and severing, the severing being performed in the area to be joined, next to the area to be joined, in the joint area or next to the joint area} - B23K 20/023: {Thermo-compression bonding} - B23K 20/22: taking account of the properties of the materials to be welded - B23K 20/24: Preliminary treatment - B23K 2101/40: Semiconductor devices - B29C 65/7412: {the joining step and the severing step being performed at different temperatures} - Y10T 156/1062: Prior to assembly - Y10T 156/12: Surface bonding means and/or assembly means with cutting, punching, piercing, severing or tearing - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method for bonding a first bond surface of a first solid substrate consisting of a first material to a second bond surface of a second solid substrate consisting of a second material, said method comprising the steps of: working one of the first and/or second bond surfaces with a cutting tool at a speed vs that is below a critical speed vk and at a temperature Ts that exceeds a critical temperature Tk, down to a surface roughness O that is less than 1 μm; bringing the first solid substrate into contact with the second solid substrate at the bond surfaces, and exposing the solid substrates that are in contact to temperature in order to form a permanent bond that is at least primarily produced by recrystallization at the bond surfaces. ## Claims ### Claim 1 Method for bonding a first bond surface of a first solid substrate consisting of a first material to a second bond surface of a second solid substrate consisting of a second material, said method comprising the steps of: working one of a first bond surface and a second bond surfaces with a cutting tool to create a metastable structure in at least the near-surface area and to produce a reduced surface roughness of less than 100 nm, bringing the first solid substrate into contact with the second solid substrate at the bond surfaces, and exposing the solid substrates that are in contact to a temperature sufficient to form a permanent bond, said permanent bond being at least primarily produced by recrystallization at the bond surfaces in each case down to a recrystallization depth R that is greater than the surface roughness O of the bond surfaces with a bond temperature TB that exceeds the recrystallization temperature. ### Claim 2 (depends on 1) Method in accordance with claim 1, in which the first and second materials are identical. ### Claim 3 (depends on 1) Method in accordance with claim 1, in which the first and/or second materials are metals. ### Claim 4 (depends on 1, 2, 3) Method in accordance with claims 1, 2 or 3 wherein the formation of the permanent bond takes place at a bond temperature TB that is greater than the critical temperature Tk. ### Claim 5 (depends on 1, 2, 3) Method in accordance with claims 1, 2 or 3 wherein the working with the cutting tool is done in such a way that an amorphous layer and/or a layer of elevated dislocation density is formed at the first and/or second bond surface. ### Claim 6 (depends on 1) Method in accordance with claims 1 2 or 3 wherein after the first working is done and before contact is made, a second working of said one of the first and second bond surfaces with a tool, especially the same tool, is carried out at a speed vo that exceeds the critical speed vk, especially at a temperature To that is below the critical temperature Tk in order to reduce the surface roughness O to less than 100 nm, preferably less than 10 nm, even more preferably less than 1 nm, and most preferably less than 0.1 nm. ### Claim 7 (depends on 1) Method in accordance with claim 1, wherein said working step produces a reduced surface roughness of less than 10 mm. ### Claim 8 (depends on 1) Method in accordance with claim 1, wherein said working step produces a reduced surface roughness of less than 1 mm. ### Claim 9 (depends on 1) Method in accordance with claim 1, wherein said working step produces a reduced surface roughness of less than 0.1 mm. ### Claim 10 Device for bonding a first bond surface of a first solid substrate consisting of a first material to a second bond surface of a second solid substrate consisting of a second material, said device comprising: a cutting tool for working one of the first and the second bond surfaces to create a metastable structure in at least the near-surface area and a reduced surface roughness of less than 100 nm, means for bringing the first solid substrate into contact with the second solid substrate at the bond surfaces, and means for exposing to temperature the solid substrates that are in contact to form a permanent bond that is at least primarily produced by recrystallization at the bond surfaces in each case down to a recrystallization depth R that exceeds the surface roughness O of the bond surfaces with a bond temperature TB that is greater than the recrystallization temperature. ### Claim 11 (depends on 10) Device in accordance with claim 10, in which the cutting tool can be adjusted in such a way that a second working is carried out at a speed vo that exceeds the critical speed vk, especially at a temperature To that is below the critical temperature Tk, in order to reduce the surface roughness O to less than 100 nm, preferably less than 10 nm, even more preferably less than 1 nm, and most preferably less than 0.1 nm. ### Claim 12 Cutting tool for working one of the first and the second bond surfaces at a speed v5 that is below a critical speed vk and at a temperature Ts that is above a critical temperature Tk and down to a surface roughness O of less than 1 μm.