# US 7,465,645 B2 · Method of detaching a layer from a wafer using a localized starting area > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,465,645 B2 - Document ID: US7465645B2 - Status: Granted - Kind: B2 - Application number: 10/766,207 - Filed: 2004-01-29 - Published: 2005-02-10 - Granted: 2008-12-16 - Earliest claimed: 2003-08-04 - Assignees: S.O.I.Tec Silicon on Insulator Technologies - Inventors: Walter Schwarzenbach; Christophe Maleville; Nadia Ben Mohamed - Web page: https://patentgrep.com/patent/US7465645B2 ## CPC - H10P 90/12: {Preparing bulk and homogeneous wafers} - H10P 90/1916: {with separation or delamination along an ion implanted layer, e.g. Smart-cut} - H10P 54/52: {by cleaving} - H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A method for detaching a layer from a wafer. A weakened zone is created in the wafer to define the layer to be detached and a remainder portion of the wafer, such that the weakened zone includes a main region and a localized super-weakened region that is more weakened than the main region. Detachment of the layer from the remainder portion of the wafer is initiated at the super-weakened region such that the detachment properties to the main region to detach the layer from the remainder portion. ## Claims ### Claim 1 A method of detaching a layer from a wafer, which comprises: creating a weakened zone in a wafer to define the layer to be detached and a remainder portion of the wafer, such that the weakened zone includes a main region and a localized super-weakened region that is more weakened than the main region, wherein the super-weakened region is created by implanting an overdose of the atomic species compared to the dose of atomic species implanted in the main region; and initiating detachment of the layer from the remainder portion at the super-weakened region by applying a controlled detachment force obtained by heating at least the weakened zone wherein the heat is applied substantially evenly over substantially the entire weakened zone, and wherein the heating is controlled for evening the heating applied to weakened zone such that the detachment initiates and propagates from the super-weakened region through the main region to detach the layer from the remainder portion; and wherein the detachment force is applied to both the super-weakened region and the main region. ### Claim 2 (depends on 1) The method of claim 1, wherein the detachment force is obtained by applying energy to weakened zone. ### Claim 3 (depends on 1) The method of claim 1, wherein the heating of the weakened zone comprises thermally annealing the wafer. ### Claim 4 (depends on 1) The method of claim 1, wherein the weakened zone is created by implanting a dose of atomic species in the wafer. ### Claim 5 (depends on 1) The method of claim 1, wherein the atomic species is applied in substantially a single operation to both the super-weakened and main regions. ### Claim 6 (depends on 1) The method of claim 1, wherein an initial dose of atomic species is applied to the weakened zone, and the overdose is applied to the super-weakened region before or after the application of the initial dose. ### Claim 7 (depends on 1) The method of claim 1, wherein the weakened zone is created by producing a porous layer in the wafer. ### Claim 8 (depends on 1) The method of claim 1, wherein the weakened zone extends through a crystalline layer of the wafer. ### Claim 9 (depends on 1) The method of claim 1, wherein the wafer comprises a semiconductor material. ### Claim 10 (depends on 1) The method of claim 1, wherein the localized super-weakened region covers an angular sector on the order of several degrees at the periphery of the weakened zone. ### Claim 11 A method of detaching a layer from a wafer, which comprises: creating a weakened zone in a wafer to define the layer to be detached and a remainder portion of the wafer, such that the weakened zone includes a main region and a localized super-weakened region that is more weakened than the main region, wherein the super-weakened region is created by implanting an overdose of the atomic species compared to the dose of atomic species implanted in the main region; and initiating detachment of the layer from the remainder portion at the super-weakened region to impart a controlled detachment force obtained by applying heat substantially evenly over substantially the entire weakened zone, and wherein the heating is controlled for evening the heating applied to the weakened zone such that the detachment initiates and propagates from the super-weakened region through the main region to detach the layer from the remainder portion, wherein the heat is applied by heating elements that are independently controlled for evening the application of heat to the weakened zone; and wherein the detachment force is applied to both the super-weakened region and the main region. ### Claim 12 (depends on 11) The method of claim 11, which further comprises flowing a heat conducting gas over the wafer during thermal annealing. ### Claim 13 (depends on 11) The method of claim 11, wherein the detachment is conducted under conditions sufficient to obtain a detached layer that is substantially homogenous and has a low surface roughness and improved homogeneity compared to the surface roughness and homogeneity obtained from a conventional detachment annealing on a wafer having a weakened zone but not a super-weakened region. ### Claim 14 (depends on 11) The method of claim 11, wherein the localized super-weakened region covers an angular sector on the order of several degrees at the periphery of the weakened zone. ### Claim 15 A method of detaching a layer from a wafer, which comprises: creating an weakened zone in a wafer to define the layer to be detached and a remainder portion of the wafer, such that the weakened zone includes a main region and a localized super-weakened region that is more weakened than the main region, wherein the super-weakened region is created by implanting an overdose of the atomic species compared to the dose of atomic species implanted in the main region; and initiating detachment of the layer from the remainder portion at the super-weakened region by applying heat a controlled detachment force obtained by heating at least the weakened zone wherein the heat is applied substantially evenly over substantially the entire weakened zone, and wherein the heating is controlled for evening the heating applied to the weakened zone such that the detachment initiates and propagates from the super-weakened region through the main region to detach the layer from the remainder portion, wherein the detachment force is applied to both the super-weakened region and the main region to obtain a detached layer that is substantially homogenous and has a low surface roughness and improved homogeneity compared to the surface roughness and homogeneity obtained from a conventional detachment annealing on a wafer having a weakened zone but not a super-weakened region. ### Claim 16 (depends on 15) The method of claim 15, wherein the localized super-weakened region covers an angular sector at the periphery of the weakened zone.