Laminated semiconductor substrate process for producing the same

• US 20060118935A1
• Filed: 04/02/2004
• Published: 06/08/2006
• Est. Priority Date: 04/02/2003
• Status: Active Grant

• Current Assignee: Industry-University Cooperation Foundation Hanyang University, Sumco Corporation
• Original Assignee: Industry-University Cooperation Foundation Hanyang University
• Inventors: Katoh, Takeo, Park, Jea Gun, Kamiyama, Eiji
• Granted Patent: US 7,491,342 B2
• Time in Patent Office: Days
• US Class Current: 257/684
• CPC Class Codes: H01L 21/30608 Anisotropic liquid etching H01L21/3063 takes precedence
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

The present invention provides a bonded substrate fabricated to have its final active layer thickness of 200 nm or lower by performing the etching by only 1 nm to 1 μm with a solution having an etching effect on a surface of an active layer of a bonded substrate which has been prepared by bonding two substrates after one of them having been ion-implanted and then cleaving off a portion thereof by heat treatment. SC-1 solution is used for performing the etching. A polishing, a hydrogen annealing and a sacrificial oxidation may be respectively applied to the active layer before and/or after the etching. The film thickness of this active layer can be made uniform over the entire surface area and the surface roughness of the active layer can be reduced as well.

Claims

1. A bonded substrate fabricated to have its final active layer thickness of 200 nm or lower by performing an etching process on a surface of an active layer formed over a support substrate by cleaving off a portion of an active layer wafer, for the purpose of controlling the thickness of said active layer, said etching process carried out by using a solution having an etching effect so as to achieve the etching by a range of 1 nm to 1 μ

m.

2. A manufacturing method of a bonded substrate having its final active layer thickness of 200 nm or lower by performing an etching process on a surface of an active layer formed over a support substrate by cleaving off a portion of an active layer wafer, for the purpose of controlling the thickness of said active layer, said etching process carried out by using a solution having an etching effect so as to achieve the etching by a range of 1 nm to 1 μ

m.

3. A manufacturing method of a bonded substrate in accordance with claim 2, in which an etching rate in said etching process is not greater than 100 nm/min.

4. A manufacturing method of a bonded substrate in accordance with claim 2, in which said solution having an etching effect is a solution of pH 9 or higher containing alkaline chemicals and an oxidizer.

5. A manufacturing method of a bonded substrate in accordance with claim 3, in which said solution having an etching effect is a solution of pH 9 or higher containing alkaline chemicals and an oxidizer.

6. A manufacturing method of a bonded substrate in accordance with claim 2, in which said solution having an etching effect is a solution of pH 9 or higher containing an aqueous solution of ammonia and an aqueous solution of hydrogen peroxide.

7. A manufacturing method of a bonded substrate in accordance with claim 3, in which said solution having an etching effect is a solution of pH 9 or higher containing an aqueous solution of ammonia and an aqueous solution of hydrogen peroxide.

8. A manufacturing method of a bonded substrate in accordance with claim 2, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

9. A manufacturing method of a bonded substrate in accordance with claim 3, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

10. A manufacturing method of a bonded substrate in accordance with claim 4, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

11. A manufacturing method of a bonded substrate in accordance with claim 5, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

12. A manufacturing method of a bonded substrate in accordance with claim 6, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

13. A manufacturing method of a bonded substrate in accordance with claim 7, in which after said etching process, a thickness of said active layer is measured and based on said obtained measurement data, said etching process is repeated until said thickness of the active layer across its entire area comes near to a predetermined value of thickness.

14. A manufacturing method of a bonded substrate in accordance with claim 2, in which one of following steps is performed on said active layer surface of said bonded substrate before said etching process, said steps including:

(1) a step of chemical mechanical polishing process taking advantage of a chemical effect and a mechanical effect at the same time;

(2) a step of hydrogen treating process for performing a heat treatment in a reducing atmosphere containing hydrogen; and

(3) a step of forming a silicon oxide film over said active layer and then removing said silicon oxide film along with a damaged portion of said active layer, which has been created in said cleaving process.

15. A manufacturing method of a bonded substrate in accordance with claim 2, in which one of following steps is performed on said active layer surface of said bonded substrate after said etching process, said steps including:

(1) a step of chemical mechanical polishing process taking advantage of a chemical effect and a mechanical effect at the same time;

(2) a step of hydrogen treating process for performing a heat treatment in a reducing atmosphere containing hydrogen; and

(3) a step of forming a silicon oxide film over said active layer and then removing said silicon oxide film along with a damaged portion of said active layer, which has been created in said cleaving process.

16. A manufacturing method of a bonded substrate in accordance with claim 2, in which one of following steps is performed on said active layer surface of said bonded substrate after and before said etching process, said steps including:

(1) a step of chemical mechanical polishing process taking advantage of a chemical effect and a mechanical effect at the same time;

(2) a step of hydrogen treating process for performing a heat treatment in a reducing atmosphere containing hydrogen; and

(3) a step of forming a silicon oxide film over said active layer and then removing said silicon oxide film along with a damaged portion of said active layer, which has been created in said cleaving process.