Method for manufacturing semiconductor devices using embrittled layers

• US 8,030,177 B2
• Filed: 11/10/2009
• Issued: 10/04/2011
• Est. Priority Date: 11/13/2008
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shimomura, Akihisa, Koyama, Masaki, Jinbo, Yasuhiro, Okuno, Naoki
• Primary Examiner(s): Le; Thao
• Assistant Examiner(s): JONES, ERIC W
• Application Number:
  US12/615,613
• Publication Number:
  US 20100120224A1
• Time in Patent Office: 693 Days
• Field of Search: 438/149, 438/150, 438/151, 438/455, 438/458, 257/350, 257/E21.7, 257/E23.002
• US Class Current: 438/458
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body

Abstract

An object is to provide a method for manufacturing an SOI substrate including a single crystal silicon film whose plane orientation is (100) and a single crystal silicon film whose plane orientation is (110) with high yield. A first single crystal silicon substrate whose plane orientation is (100) is doped with first ions to form a first embrittlement layer. A second single crystal silicon substrate whose plane orientation is (110) is doped with second ions to selectively form a second embrittlement layer. Only part of the first single crystal silicon substrate is separated along the first embrittlement layer by first heat treatment, thereby forming a first single crystal silicon film. A region of the second single crystal silicon substrate, in which the second embrittlement layer is not formed, is removed. Part of the second single crystal silicon substrate is separated along the second embrittlement layer by second heat treatment, thereby forming a second single crystal silicon film.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of:

forming a first insulating film over a surface of a first single crystal silicon substrate;

forming a second insulating film over a surface of a second single crystal silicon substrate;

doping an entire surface of the first single crystal silicon substrate with first ions through the first insulating film to form a first embrittlement layer in the first single crystal silicon substrate;

doping the second single crystal silicon substrate with second ions through the second insulating film to selectively form a second embrittlement layer in the second single crystal silicon substrate;

bonding the first single crystal silicon substrate and the second single crystal silicon substrate to each other with the first insulating film and the second insulating film interposed therebetween;

separating part of the first single crystal silicon substrate along the first embrittlement layer by first heat treatment to form a first single crystal silicon film over the second single crystal silicon substrate with the first insulating film and the second insulating film interposed therebetween;

forming a third insulating film over the first single crystal silicon film;

removing a region of the second single crystal silicon substrate, in which the second embrittlement layer is not formed;

bonding a base substrate and the second single crystal silicon substrate to each other with the third insulating film interposed therebetween;

separating part of the second single crystal silicon substrate along the second embrittlement layer by second heat treatment to form a second single crystal silicon film over the base substrate with the first insulating film and the second insulating film interposed therebetween;

selectively removing the second single crystal silicon film to form an island-like second single crystal silicon film, and removing part of the first insulating film and part of the second insulating film to expose the first single crystal silicon film; and

selectively removing the first single crystal silicon film to form an island-like first single crystal silicon film,

wherein in the case where a plane orientation of a main surface of the first single crystal silicon substrate is (100), a plane orientation of a main surface of the second single crystal silicon substrate is (110),

wherein in the case where the plane orientation of the main surface of the first single crystal silicon substrate is (110), the plane orientation of the main surface of the second single crystal silicon substrate is (100),

wherein a dose of the second ions is smaller than a dose of the first ions, and

wherein a temperature of the second heat treatment is higher than a temperature of the first heat treatment.

2. The method for manufacturing a semiconductor device, according to claim 1,

wherein the first ions and the second ions include at least one of H⁺, H₂⁺, and H₃⁺,

wherein the dose of the first ions is 2.5×

10¹⁶ to 2.7×

10¹⁶ cm<sup>−

2</sup>,

wherein the dose of the second ions is 1.9×

10¹⁶ to 2.1×

10¹⁶ cm<sup>−

2</sup>,

wherein the temperature of the first heat treatment is 470 to 480°

C., and

wherein the temperature of the second heat treatment is 490°

C. or higher.

3. A method for manufacturing a semiconductor device, comprising the steps of:

forming a first insulating film over a surface of a first single crystal silicon substrate;

forming a second insulating film over a surface of a second single crystal silicon substrate;

forming a first mask which entirely covers a peripheral portion of the second single crystal silicon substrate over the second insulating film;

doping an entire surface of the first single crystal silicon substrate with first ions through the first insulating film to form a first embrittlement layer in the first single crystal silicon substrate;

doping the second single crystal silicon substrate with second ions through the second insulating film with the use of the first mask to selectively form a second embrittlement layer in the second single crystal silicon substrate;

removing the first mask;

bonding the first single crystal silicon substrate and the second single crystal silicon substrate to each other with the first insulating film and the second insulating film interposed therebetween;

separating part of the first single crystal silicon substrate along the first embrittlement layer by first heat treatment to form a first single crystal silicon film over the second single crystal silicon substrate with the first insulating film and the second insulating film interposed therebetween;

forming a third insulating film over the first single crystal silicon film;

forming a second mask which entirely covers the second embrittlement layer over the third insulating film;

removing a peripheral portion of the third insulating film, a peripheral portion of the first insulating film, a peripheral portion of the second insulating film, and the peripheral portion of the second single crystal silicon substrate with the use of the second mask;

bonding a base substrate and the second single crystal silicon substrate to each other with the third insulating film interposed therebetween;

separating part of the second single crystal silicon substrate along the second embrittlement layer by second heat treatment to form a second single crystal silicon film over the base substrate with the first insulating film and the second insulating film interposed therebetween;

selectively removing the second single crystal silicon film to form an island-like second single crystal silicon film, and removing part of the first insulating film and part of the second insulating film to expose the first single crystal silicon film; and

selectively removing the first single crystal silicon film to form an island-like first single crystal silicon film,

wherein in the case where a plane orientation of a main surface of the first single crystal silicon substrate is (100), a plane orientation of a main surface of the second single crystal silicon substrate is (110),

wherein in the case where the plane orientation of the main surface of the first single crystal silicon substrate is (110), the plane orientation of the main surface of the second single crystal silicon substrate is (100),

wherein a dose of the second ions is smaller than a dose of the first ions, and

wherein a temperature of the second heat treatment is higher than a temperature of the first heat treatment.

4. The method for manufacturing a semiconductor device, according to claim 3,

wherein the first ions and the second ions include at least one of H⁺, H₂⁺, and H₃⁺,

wherein the dose of the first ions is 2.5×

10¹⁶ to 2.7×

10¹⁶ cm<sup>−

2</sup>,

wherein the dose of the second ions is 1.9×

10¹⁶ to 2.1×

10¹⁶ cm<sup>−

2</sup>,

wherein the temperature of the first heat treatment is 470 to 480°

C., and

wherein the temperature of the second heat treatment is 490°

C. or higher.