# US 2019/0355699 A1 · Methods and Systems for Adjusting Wafer Deformation During Wafer Bonding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0355699 A1 - Document ID: US20190355699A1 - Status: Published application - Kind: A1 - Application number: 16/046,733 - Filed: 2018-07-26 - Published: 2019-11-21 - Earliest claimed: 2018-05-17 - Assignees: Yangtze Memory Technologies Co., Ltd. - Applicants: Yangtze Memory Technologies Co., Ltd. - Inventors: Shuai Guo - Web page: https://patentgrep.com/patent/US20190355699A1 ## CPC - H10W 90/00: Package configurations - B81C 3/004: {Active alignment, i.e. moving the elements in response to the detected position of the elements using internal or external actuators} - H10P 72/0428: {Apparatus for mechanical treatment or grinding or cutting} - H10P 72/0616: {Monitoring of warpages, curvatures, damages, defects or the like} - H10P 72/53: {using optical controlling means} - H10P 72/78: using vacuum or suction, e.g. Bernoulli chucks - H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes} - H10W 46/00: Marks applied to devices, e.g. for alignment or identification - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - H10W 46/301: {for alignment} - H10W 46/501: {for use before dicing} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Embodiments of methods and systems for adjusting wafer deformation during wafer bonding are provided. The method comprises: releasing inner rings of a first wafer, and applying a first gas pressure to the inner rings of the first wafer, such that the inner rings of the first wafer are in contact with a second wafer; releasing middle rings of the first wafer, such that the middle rings of the first wafer are deformed under a second gas pressure and in contact with the second wafer; releasing inner rings of the second wafer, and applying a third gas pressure less than the first gas pressure to the inner rings of the second wafer; releasing middle rings of the second wafer; and releasing outer rings of the first wafer and releasing outer rings of the second wafer simultaneously. ## Claims ### Claim 1 A method for bonding wafers, comprising: (i) releasing inner rings of a first wafer from a first chuck, and applying a first gas pressure to the inner rings of the first wafer, such that the inner rings of the first wafer are in contact with a second wafer; (ii) releasing middle rings of the first wafer from the first chuck, such that the middle rings of the first wafer are deformed under a second gas pressure and in contact with the second wafer; (iii) releasing inner rings of the second wafer from a second chuck, and applying a third gas pressure to the inner rings of the second wafer, wherein the third gas pressure is smaller than the first gas pressure; (iv) releasing middle rings of the second wafer from the second chuck; and (v) releasing outer rings of the first wafer from the first chuck and releasing outer rings of the second wafer from the second chuck simultaneously. ### Claim 2 (depends on 1) The method of claim 1, before operation (i), further comprising: bonding a first pair of wafers including a plurality of bonding alignment mark pairs on the first pair of wafers, wherein each wafer has a corresponding bonding alignment mark from each of the plurality of bonding alignment mark pairs; analyzing a run-out misalignment between the first pair of wafers based on a measurement of the plurality of bonding alignment mark pairs; and determining an expansion rate of one of a second pair of wafers based on the analysis for compensating the run-out misalignment; wherein the second pair of wafers includes the first wafer and the second wafer, and the first gas pressure is determined based at least on the expansion rate. ### Claim 3 (depends on 2) The method of claim 2, before operation (i), further comprising: determining the first wafer is one of the second pair of wafers based on a sign of the run-out misalignment between the first pair of wafers; determining the expansion rate of the first wafer based on a magnitude of the run-out misalignment between the first pair of wafers; and adjusting an initial distance between the first wafer and the second wafer based at least on the expansion rate. ### Claim 4 (depends on 2) The method of claim 2, wherein operation (i) comprises: purging gas, by a plurality of vents in a region of the first chuck corresponding to the inner rings of the first wafer, to generate the first gas pressure in a space between the inner rings of the first wafer and the first chuck, such that the inner rings of the first wafer protrude from the first chuck; and evacuating gas, by a plurality of vents in a region of the first chuck corresponding to the middle rings and the outer rings of the first wafer, such that the middle rings and outer rings of the first wafer are attached on the first chuck. ### Claim 5 (depends on 4) The method of claim 4, wherein operation (ii) comprises: stopping evacuating gas, by a plurality of vents in a region of the first chuck corresponding to the middle rings of the first wafer, such that the gas in the space between the inner rings of the first wafer and the first chuck fills into a space between the middle rings of the first wafer and the first chuck to generate the second gas pressure; and maintaining the second gas pressure for a time period determined based at least on the expansion rate, such that the middle rings of the first wafer are deformed under the second gas pressure. ### Claim 6 (depends on 5) The method of claim 5, further comprising: evacuating gas, during operations (i) and (ii), by a plurality of vents on the second chuck, such that the second wafer is entirely attached on the second chuck. ### Claim 7 (depends on 5) The method of claim 5, wherein operation (iii) comprises: purging gas, by a plurality of vents in a region of the second chuck corresponding to the inner rings of the second wafer, to generate the third gas pressure in a space between the inner rings of the second wafer and the second chuck; and evacuating gas, by a plurality of vents in a region of the second chuck corresponding to the middle rings and the outer rings of the second wafer, such that the middle rings and outer rings of the second wafer are attached on the second chuck. ### Claim 8 (depends on 7) The method of claim 7, wherein operation (iv) comprises: stopping evacuating gas, by a plurality of vents in a region of the second chuck corresponding to the middle rings of the second wafer, such that the gas in the space between the inner rings of the second wafer and the second chuck fills into a space between the middle rings of the second wafer and the second chuck to generate a fourth gas pressure; wherein a deformation of the middle rings of the second wafer under the fourth gas pressure is less than the a deformation of the middle rings of the first wafer under the second gas pressure. ### Claim 9 (depends on 8) The method of claim 8, wherein operation (v) comprises: stopping evacuating gas simultaneously, by a plurality of vents in a region of the first chuck corresponding to the outer rings of the first wafer and a plurality of vents in a region of the second chuck corresponding to the outer rings of the second wafer, such that the first wafer and the second wafer are bonded with each other. ### Claim 10 A system for bonding wafers, comprising: a wafer support module including a first chuck and a second chuck configured to support a first pair of wafers respectively; an alignment monitoring module configured to measure positions of a plurality of bonding alignment mark pairs on the first pair of wafers; a hardware processor configured to analyze a run-out misalignment between the first pair of wafers based on the positions of the plurality of bonding alignment mark pairs; a wafer position adjustment module configured to adjust positions of wafer support module; and a wafer deformation adjustment module configured to compensate the run-out misalignment during bonding of a second pair of wafers by adjusting gas pressures between each of the second pair of wafers and the corresponding chuck. ### Claim 11 (depends on 10) The system of claim 10, wherein the wafer deformation adjustment module is configured to: (i) release inner rings of a first wafer from a first chuck, and apply a first gas pressure to the inner rings of the first wafer, such that the inner rings of the first wafer are in contact with a second wafer; (ii) release middle rings of the first wafer from the first chuck, such that the middle rings of the first wafer are deformed under a second gas pressure and in contact with the second wafer; (iii) release inner rings of the second wafer from a second chuck, and apply a third gas pressure to the inner rings of the top wafer, wherein the third gas pressure is smaller than the first gas pressure; (iv) release middle rings of the second wafer from the second chuck; and (v) release outer rings of the first wafer from the first chuck and releasing outer rings of the second wafer from the second chuck simultaneously. ### Claim 12 (depends on 11) The system of claim 11, wherein the hardware processor is further configured to: determining the first wafer is one of the second pair of wafers based on a sign of the run-out misalignment between the first pair of wafers; determine an expansion rate of one of the second pair of wafers based on the analysis for the run-out misalignment between the first pair of wafers; and determine the initial distance between a first wafer and a second wafer of the second pair of wafers, and the first gas pressure based at least on the expansion rate. ### Claim 13 (depends on 11) The system of claim 11, wherein the hardware processor is further configured to: calculating a run-out misalignment between the bonding alignment marks of each bonding alignment mark pair; and calculating an average of the run-out misalignments corresponding to the plurality of bonding alignment mark pairs as the run-out misalignment between the first pair of wafers. ### Claim 14 (depends on 13) The system of claim 13, wherein the hardware processor is further configured to: determining a first distance between a center of a top wafer of the first pair of wafers and a first bonding alignment mark in a bonding alignment mark pair that is on the top wafer; determining a second distance between the first bonding alignment mark and a second bonding alignment mark in the bonding alignment mark pair that is on a bottom wafer of the first pair of wafers; determining an angle between a connection line of the bonding alignment mark pair and a radiation direction of the first bonding alignment mark on the top wafer; and calculating the run-out misalignment between the bonding alignment mark pair based on the first distance, the second distance, and the angle. ### Claim 15 (depends on 12) The system of claim 12, wherein the hardware processor is further configured to: control a plurality of vents in a region of the first chuck corresponding to the inner rings of the first wafer to purge gas to generate the first gas pressure in a space between the inner rings of the first wafer and the first chuck, such that the inner rings of the first wafer protrude from the first chuck; and control a plurality of vents in a region of the first chuck corresponding to the middle rings and the outer rings of the first wafer to evacuate gas, such that the middle rings and outer rings of the first wafer are attached on the first chuck. ### Claim 16 (depends on 15) The system of claim 15, wherein the hardware processor is further configured to: control a plurality of vents in a region of the first chuck corresponding to the middle rings of the first wafer to stop evacuating gas, such that the gas in the space between the inner rings of the first wafer and the first chuck fills into a space between the middle rings of the first wafer and the first chuck to generate the second gas pressure; and control the plurality of vents on the first chuck to maintain the second gas pressure for a time period determined based at least on the expansion rate, such that the middle rings of the first wafer are deformed under the second gas pressure. ### Claim 17 (depends on 16) The system of claim 16, wherein the hardware processor is further configured to: control a plurality of vents on the second chuck to evacuate gas during operations (i) and (ii), such that the second wafer is entirely attached on the second chuck. ### Claim 18 (depends on 17) The system of claim 17, wherein the hardware processor is further configured to: control a plurality of vents in a region of the second chuck corresponding to the inner rings of the second wafer to purge gas to generate the third gas pressure in a space between the inner rings of the second wafer and the second chuck; and control a plurality of vents in a region of the second chuck corresponding to the middle rings and the outer rings of the second wafer to evacuate gas, such that the middle rings and outer rings of the second wafer are attached on the second chuck. ### Claim 19 (depends on 18) The system of claim 18, wherein the hardware processor is further configured to: control a plurality of vents in a region of the second chuck corresponding to the middle rings of the second wafer to stop evacuating gas, such that the gas in the space between the inner rings of the second wafer and the second chuck fills into a space between the middle rings of the second wafer and the second chuck to generate a fourth gas pressure; wherein a deformation of the middle rings of the second wafer under the fourth gas pressure is less than the a deformation of the middle rings of the first wafer under the second gas pressure. ### Claim 20 (depends on 19) The system of claim 19, wherein the hardware processor is further configured to: control a plurality of vents in a region of the first chuck corresponding to the outer rings of the first wafer and a plurality of vents in a region of the second chuck corresponding to the outer rings of the second wafer to stop evacuating gas simultaneously, such that the first wafer and the second wafer are bonded with each other.