Method for producing composite wafer having oxide single-crystal film

Patent metadata

Field	Value
Publication number	US-10770648-B2
Application number	US-201615577456-A
Country	US
Kind code	B2
Filing date	Jun 1, 2016
Priority date	Jun 2, 2015
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

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.

First claim

The invention claimed is:

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 5.0×10 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 .

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

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

• H10P95/00

  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

• H10P95/90

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

• H10P30/20

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