Method for producing composite wafer having oxide single-crystal film

Patent metadata

Field	Value
Publication number	US-10727396-B2
Application number	US-201615577615-A
Country	US
Kind code	B2
Filing date	Jun 1, 2016
Priority date	Jun 2, 2015
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

Provided is a composite wafer (c-wafer) having an oxide single-crystal film transferred onto a support wafer (s-wafer), the film being a lithium tantalate or lithium niobate film, and c-wafer being unlikely to have cracking or peeling caused in the lamination interface between the film and s-wafer. More specifically, provided is a method of producing c-wafer, including steps of: implanting hydrogen atom ions or molecule ions from a surface of the oxide wafer (o-wafer) to form an ion-implanted layer inside thereof; subjecting at least one of the surface of o-wafer and a surface of s-wafer to surface activation; bonding the surfaces together to obtain a laminate; providing at least one of the surfaces of the laminate with a protection wafer having thermal expansion coefficient smaller than that of o-wafer; and heat-treating the laminate with the protection wafer at 80° C. or higher to split the laminate along the layer to obtain c-wafer.

First claim

The invention claimed is:

1. A method of producing a composite wafer having an oxide single-crystal film on a support wafer, the method 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;
providing at least one of surfaces of the laminate with a protection wafer having a thermal expansion coefficient smaller than that of the oxide single-crystal wafer; and
heat-treating the laminate provided with the protection wafer at a temperature of 80° C. or higher 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 5.0×10 16 atom/cm 2 to 2.75×10 17 atom/cm 2 and an implantation dose of the hydrogen molecule ions is from 2.5×10 16 atoms/cm 2 to 1.37×10 17 atoms/cm 2 ,
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 of 80° C. or higher in the step of heat-treating is from 80 to 150° C. in a case where the support wafer is the sapphire wafer, from 80 to 125° C. in a case where the support wafer is the silicon wafer or a silicon wafer with an oxide film, and from 80 to 110° C. in a case where the support wafer is the glass wafer.

2. The method of producing a composite wafer according to claim 1 , wherein the protection wafer is fixed through a double sided tape or an adhesive.

3. The method of producing a composite wafer according to claim 2 , wherein the surface activation treatment is selected from the group consisting of ozone water treatment, UV ozone treatment, ion beam treatment, and plasma treatment.

4. The method of producing a composite wafer according to claim 3 , wherein the protection wafer is selected from the group consisting of a sapphire wafer, a silicon wafer, and a glass wafer.

5. The method of producing a composite wafer according to claim 2 , wherein the protection wafer is selected from the group consisting of a sapphire wafer, a silicon wafer, and a glass wafer.

6. 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.

7. The method of producing a composite wafer according to claim 6 , wherein the protection wafer is selected from the group consisting of a sapphire wafer, a silicon wafer, and a glass wafer.

8. The method of producing a composite wafer according to claim 1 , wherein the protection wafer is selected from the group consisting of a sapphire wafer, a silicon wafer, and a glass wafer.

Assignees

• Shinetsu Chemical Co

Inventors

• Akiyama Shoji
• Kawai Makoto

Classifications

• H10W10/181

  Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P90/1916 Primary

  with separation or delamination along an ion implanted layer, e.g. Smart-cut · CPC title

• H10P30/20

  into semiconductor materials, e.g. for doping · CPC title