# US 2013/0156989 A1 · Manufacturing a flexible structure by transfers of layers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156989 A1 - Document ID: US20130156989A1 - Status: Published application - Kind: A1 - Application number: 13/718,037 - Filed: 2012-12-18 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Inventors: Hubert MORICEAU; Maxime ARGOUD; Frank FOURNEL; Frederic MAZEN; Christophe MORALES - Web page: https://patentgrep.com/patent/US20130156989A1 ## CPC - B32B 38/10: Removing layers, or parts of layers, mechanically or chemically - B32B 3/02: characterised by features of form at particular places, e.g. in edge regions {(non-uniform thickness B32B3/263)} - H10P 90/1916: {with separation or delamination along an ion implanted layer, e.g. Smart-cut} - H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers} - Y10T 428/21: Circular sheet or circular blank - Y10T 428/24942: including components having same physical characteristic in differing degree - Y10T 428/24967: Absolute thicknesses specified - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - 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 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method for manufacturing a flexible structure including implanting ionic species in first and second source substrates so as to form first and second embrittlement regions respectively, delimiting first and second thin films, providing a flexible substrate, the stiffness R of which is less than or equal to 107 GPa·μm3, securing the first and second thin films to the first and second faces of the flexible substrate respectively so as to form a stack including the flexible structure delimited by the first and second embrittlement regions, the flexible structure having a stiffening effect suitable for allowing transfers of the first and second thin films, and applying a thermal budget so as to transfer the first and second thin films onto the flexible substrate. ## Claims ### Claim 1 A method for manufacturing a flexible structure, wherein the method comprises the following steps: implanting ionic species in a first source substrate so as to form a first embrittlement region delimiting a first thin film comprising a single-crystal material, implanting ionic species in a second source substrate so as to form a second embrittlement region delimiting a second thin film comprising a single-crystal material, providing a flexible substrate, the stiffness R of which is less than or equal to 107 GPa·μm3, securing the first and second thin films respectively to the first face and to the second face of the flexible substrate so as to form a stack including the flexible structure delimited by the first and second embrittlement regions, the flexible structure having a stiffening effect suitable for allowing transfers of the first and second thin films, and applying a fracture thermal budget for transferring the first and second thin films onto the flexible substrate. ### Claim 2 (depends on 1) The method according to claim 1, wherein before the securing step, the method comprises the steps: forming at least one primary stiffening film on the first thin film, and forming at least one secondary stiffening film on the second thin film, the cumulated stiffness of the primary and secondary stiffening films being less than or equal to the stiffness R. ### Claim 3 (depends on 1) The method according to claim 1, wherein before the securing step, the method comprises the steps: forming at least one primary stiffening film on the first face of the flexible substrate, and forming at least one secondary stiffening film on the second face of the flexible substrate, the cumulated stiffness of the primary and secondary stiffening films being less than or equal to the stiffness R. ### Claim 4 (depends on 1) The method according to claim 1, wherein before the securing step, the method comprises the steps: forming at least one primary stiffening film on the first face of the flexible substrate, and forming at least one secondary stiffening film on the second thin film, the cumulated stiffness of the primary and secondary stiffening films being less than or equal to the stiffness R. ### Claim 5 (depends on 2) The method according to claim 2, wherein the method comprises the steps forming the primary stiffening film on the first thin film, forming the secondary stiffening film on the second thin film and wherein the securing step comprises the steps: forming a first layer of an adhesive material, between the primary stiffening film and the first face of the flexible substrate, and forming a second layer of an adhesive material between the secondary stiffening film and the second face of the flexible substrate, the adhesive material comprising at least one of DVD-bis-BCB, polyimides and photosensitive polymers. ### Claim 6 (depends on 2) The method according to claim 2, wherein the method comprises the steps: forming the primary stiffening film on the first face of the flexible substrate, forming the secondary stiffening film on the second face of the flexible substrate, and wherein the securing step comprises direct bonding between the primary stiffening film and the first thin film and direct bonding between the secondary stiffening film and the second thin film. ### Claim 7 (depends on 1) The method according to claim 1, wherein the steps for implanting ionic species into the first and second source substrates comprise a step for implanting different doses of ionic species into the first and second source substrates. ### Claim 8 (depends on 7) The method according claim 7, wherein the step for applying the fracture thermal budget comprises: a first step comprising the application of a first thermal budget so as to transfer one of the first or second thin films on to the flexible substrate; and a second step comprising the application of a second additional thermal budget so as to transfer the other one of the first and second thin films onto the flexible substrate. ### Claim 9 (depends on 1) The method according to claim 1, wherein the method comprises the application of at least one microtechnology or microelectronics step applied in or on the free face of the first transferred thin film. ### Claim 10 (depends on 1) The method according to claim 1, wherein the method comprises the application of at least one microtechnology or microelectronics step applied in or on the free face of the first transferred thin film and of the second transferred thin film. ### Claim 11 (depends on 2) The method according to claim 2, wherein the method comprises selecting a different thickness for the primary and secondary stiffening films. ### Claim 12 (depends on 2) The method according to claim 2, wherein the primary and secondary stiffening films have a thickness comprised between 0.1 micrometers and 30 micrometers, a Young's modulus greater than or equal to 10 GPa, and comprises a material in SiOxNy or in AlxOy. ### Claim 13 (depends on 1) The method according to claim 1, wherein the flexible substrate comprises at least one of metal sheets, rubber polymers, and glassy polymers. ### Claim 14 (depends on 1) The method according to claim 1, wherein the material of the first and second thin films is a single-crystal material comprising at least one of piezoelectric materials, magnetic materials, semiconducting materials, and a material comprising elements from columns III and IV. ### Claim 15 An intermediate structure comprising from a base to a surface: one of first or second thin films secured to a negative of a first or second embrittled source substrate respectively, one of primary or secondary stiffening films on said first or second thin film secured to a negative a flexible substrate, a stiffness R of which is less than or equal to 107 GPa·μm3, another of the primary or secondary stiffening films, the cumulated stiffness of the primary and secondary stiffening films being less than or equal to R, another of the first or second thin films, transferred onto the flexible substrate, the transferred thin film having a thickness of less than 5 micrometers. ### Claim 16 (depends on 12) A flexible structure suitable for being grasped for applying at least one microtechnology, microelectronics or cleaning step, obtained from the intermediate structure according to claim 12, comprising from a surface to a base: a first thin film with a thickness of less than 5 micrometers, a primary stiffening film, a flexible substrate, the stiffness R of which is less than or equal to 107 GPa·μm3, a secondary stiffening film, a second thin film with a thickness of less than 5 micrometers, the flexible structure having a radius of curvature greater than 20 cm in the absence of external stress. ### Claim 17 (depends on 15) The flexible structure according to claim 15, wherein the first and second thin films include silicon and have identical thickness, comprised between 0.01 micrometers and 2.5 micrometers, the primary and secondary stiffening films include silicon oxide SiO2 and have identical thickness, comprised between 0.1 micrometers and 10 micrometers, and the flexible substrate is in a glassy polymer having a thickness comprised between 100 and 200 micrometers.