# US 10,770,648 B2 · Method for producing composite wafer having oxide single-crystal film

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,770,648 B2
- Document ID: US10770648B2
- Status: Granted
- Kind: B2
- Application number: 15/577,456
- Filed: 2016-06-01
- Published: 2018-05-31
- Granted: 2020-09-08
- Earliest claimed: 2015-06-02
- Assignees: Shin-Etsu Chemical Co., Ltd.
- Applicants: Shin-Etsu Chemical Co., Ltd.
- Inventors: Shoji Akiyama; Makoto Kawai
- Web page: https://patentgrep.com/patent/US10770648B2

## CPC

- H10N 30/085: by machining
- B32B 18/00: Layered products essentially comprising ceramics, e.g. refractory products
- B32B 37/18: involving the assembly of discrete sheets or panels only
- B32B 38/0036: {Heat treatment (for heating or cooling of layers during lamination B32B37/06, B32B37/08)}
- B32B 38/10: Removing layers, or parts of layers, mechanically or chemically
- C23C 14/48: Ion implantation
- C23C 14/5833: {Ion beam bombardment}
- H10N 30/072: by laminating or bonding of piezoelectric or electrostrictive bodies
- H10N 30/8542: {Alkali metal based oxides, e.g. lithium, sodium or potassium niobates}
- H10P 90/1916: {with separation or delamination along an ion implanted layer, e.g. Smart-cut}
- H10P 95/00: Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
- H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers}
- B32B 2457/00: Electrical equipment
- C30B 29/30: Niobates; Vanadates; Tantalates
- H03H 9/02559: {of lithium niobate or lithium-tantalate substrates}
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- 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
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)

## Abstract

A composite wafer has an oxide single-crystal film transferred onto a support wafer, the film being a lithium tantalate or lithium niobate film, and the composite wafer being unlikely to have cracking or peeling caused in the lamination interface between the film and the support wafer. More specifically, a method of producing the composite wafer, includes steps of: implanting hydrogen atom ions or molecule ions from a surface of the oxide wafer to form an ion-implanted layer inside thereof; subjecting at least one of the surface of the oxide wafer and a surface of the support wafer to surface activation treatment; bonding the surfaces together to obtain a laminate; heat-treating the laminate at 90° C. or higher at which cracking is not caused; and applying ultrasonic vibration to the heat-treated laminate to split along the ion-implanted layer to obtain the composite wafer.

## Claims

### Claim 1

A method of producing a composite wafer having an oxide single-crystal film on a support wafer, comprising steps of:
implanting hydrogen atom ions or hydrogen molecule ions into an oxide single-crystal wafer through a surface thereof, which wafer is a lithium tantalate or lithium niobate wafer, to form an ion-implanted layer inside the oxide single-crystal wafer;
subjecting at least one of the surface of the oxide single-crystal wafer and a surface of a support wafer to be laminated with the oxide single-crystal wafer to surface activation treatment;
after the surface activation treatment, bonding the surface of the oxide single-crystal wafer to the surface of the support wafer to obtain a laminate;
heat-treating the laminate at a temperature of 90° C. or higher at which cracking is not caused; and
applying ultrasonic vibration to the heat-treated laminate to split the laminate along the ion-implanted layer to obtain an oxide single-crystal film transferred onto the support wafer;
wherein an implantation dose of the hydrogen atom ions is from 5.0×1016 atom/cm2 to 2.75×1017 atom/cm2 and an implantation dose of the hydrogen molecule ions is from 2.5×1016 atoms/cm2 to 1.37×1017 atoms/cm2.

### Claim 2 (depends on 1)

The method of producing a composite wafer according to claim 1, wherein the support wafer is selected from the group consisting of a sapphire wafer, a silicon wafer, a silicon wafer with an oxide film and a glass wafer, and the temperature in the step of heat-treating is from 90 to 225° C. in a case where the support wafer is the sapphire wafer; from 90° C. to 200° C. in a case where the support wafer is the silicon wafer or the silicon wafer with an oxide film; and from 90 to 110° C. in a case where the support wafer is the glass wafer.

### Claim 3 (depends on 1)

The method of producing a composite wafer according to claim 1, wherein a difference between a temperature at the bonding to obtain the laminate and a temperature of the laminate during the application of the ultrasonic vibration is from 0 to 40° C.

### Claim 4 (depends on 1)

The method of producing a composite wafer according to claim 1, wherein the surface activation treatment is selected from the group consisting of ozone water treatment, UV ozone treatment, ion beam treatment, and plasma treatment.

### Claim 5 (depends on 1)

The method of producing a composite wafer according to claim 1, wherein the step of applying ultrasonic vibration comprises bringing a vibrator into contact with a side surface of the laminate.

### Claim 6 (depends on 1)

The method of producing a composite wafer according to claim 1, wherein the step of applying ultrasonic vibration includes applying the ultrasonic vibration to the laminate via a liquid.