Gallium oxide semiconductor structure and preparation method therefor

Abstract

The present invention provides a method for preparing a gallium oxide semiconductor structure and a gallium oxide semiconductor structure obtained thereby. The method comprises: providing a gallium oxide single-crystal wafer (1) having an implantation surface (1a) (S1); performing an ion implantation from the implantation surface (1a) into the gallium oxide single-crystal wafer (1), such that implanted ions reach a preset depth and an implantation defect layer (11) is formed at the preset depth (S2); bonding the implantation surface (1a) to a high thermal conductivity substrate (2) to obtain a first composite structure (S3); performing an annealing treatment on the first composite structure such that the gallium oxide single-crystal wafer (1) in the first composite structure is peeled off along the implantation defect layer (11), thereby obtaining a second composite structure and a third composite structure (S4); and performing a surface treatment on the second composite structure to remove a first damaged layer (111), so as to obtain a gallium oxide semiconductor structure comprising a first gallium oxide layer (12) and the high thermal conductivity substrate (2) (S5). In the gallium oxide semiconductor structure formed using the above method, the first gallium oxide layer (12) is integrated with the high thermal conductivity substrate (2) to effectively improve the thermal conductivity of the first gallium oxide layer (12).

Claims

1. A method for preparing a gallium oxide semiconductor structure, comprising following steps: a step S1, providing a gallium oxide single-crystal wafer having an implantation surface, wherein the gallium oxide single-crystal wafer has a crystal orientation of (?201) or (001), the gallium oxide single-crystal wafer is Sn-doped or Fe-doped single-crystal wafer; a step S2, performing an ion implantation into the implantation surface of the gallium oxide single-crystal wafer, such that implanted ions reach a preset depth and an implantation defect layer is formed at the preset depth, and a first gallium oxide layer and a second gallium oxide layer are formed on opposite sides of the implantation defect layer; a step S3, bonding the implantation surface to a high thermal conductivity substrate to obtain a first composite structure including the gallium oxide single-crystal wafer and the high thermal conductivity substrate, wherein the implantation surface and the high thermal conductivity substrate are bonded via metal bonding or anodic bonding; a step S4, performing an annealing treatment on the first composite structure such that the gallium oxide single-crystal wafer in the first composite structure is peeled off along the implantation defect layer, thereby obtaining a second composite structure and a third composite structure, wherein the implantation defect layer forms a first damaged layer and a second damaged layer, the second composite structure includes the first damaged layer, the first gallium oxide layer and the high thermal conductivity substrate, and the third composite structure includes the second damaged layer and the second gallium oxide layer; a step S5, performing a surface treatment on the second composite structure to remove the first damaged layer, so as to obtain the gallium oxide semiconductor structure comprising the first gallium oxide layer and the high thermal conductivity substrate.

2. The method according to claim 1, wherein the gallium oxide single-crystal wafer is ?-type gallium oxide single-crystal wafer or ?-type gallium oxide single-crystal wafer.

3. The method according to claim 1, wherein, in the step S2, H ions and/or He ions are implanted from the implantation surface.

4. The method according to claim 3, wherein the preset depth ranges from approximately 20 nm to 20 ?m.

5. The method according to claim 3, wherein the energy of the ion implantation ranges from approximately 5 keV to 1000 keV, the dose ranges from approximately 1?10.sup.16 ions/cm.sup.2 to 6?10.sup.17 ions/cm.sup.2, a.sup.nd the temperature ranges from approximately ?20? C. to 300? C.

6. The method according to claim 1, wherein the high thermal conductivity substrate is a substrate or a composite substrate of at least two substrates selected from the group consisting of a silicon substrate, a silicon oxide substrate, a diamond substrate, an aluminum nitride substrate, and a silicon carbide substrate.

7. The method according to claim 1, wherein, in the step S4, the annealing treatment is carried out in a vacuum environment or in a protective atmosphere formed by at least one of nitrogen, oxygen and inert gas, the annealing temperature ranges from approximately 50? C. to 700? C., and the annealing time ranges from approximately 1 min to 24 h.

8. The method according to claim 1, wherein, in the step S5, the surface treatment is at least one treatment selected from the group consisting of chemical mechanical polishing, chemical etching, plasma etching, and low energy ion sputtering.

9. The method according to claim 1, wherein the method further comprises performing a second surface treatment on the third composite structure to remove the second damaged layer.

10. A gallium oxide semiconductor structure, wherein the gallium oxide semiconductor structure is obtained according to the method of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view of the gallium oxide single-crystal wafer before the implantation provided by the method for preparing the gallium oxide semiconductor structure according to the present invention;

(2) FIG. 2 is a sectional view of the gallium oxide single-crystal wafer after the implantation provided by the method for preparing the gallium oxide semiconductor structure according to the present invention;

(3) FIG. 3 is a sectional view of the first composite structure obtained by bonding the gallium oxide single-crystal wafer after the implantation and the high thermal conductivity substrate provided by the method for preparing the gallium oxide semiconductor structure according to the present invention;

(4) FIG. 4 is a sectional view of the peeling of the first composite structure off along the implantation defect layer provided by the method for preparing the gallium oxide semiconductor structure according to the present invention;

(5) FIG. 5 is a sectional view of the gallium oxide semiconductor structure provided by the method for preparing the gallium oxide semiconductor structure according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

(7) The method for preparing a gallium oxide semiconductor structure, comprising:

(8) 1) providing a gallium oxide single-crystal wafer 1 having an implantation surface 1a, as shown in FIG. 1;

(9) 2) performing an ion implantation from the implantation surface 1a into the gallium oxide single-crystal wafer 1 in the direction of arrow, as shown in FIG. 2, such that an implantation defect layer 11 in the gallium oxide single-crystal wafer 1 is formed at a preset depth from the implantation surface 1a, and a first gallium oxide layer 12 and a second gallium oxide layer 13 are formed on opposite sides of the implantation defect layer 11;

(10) 3) bonding the implantation surface 1a to a high thermal conductivity substrate 2, as shown in FIG. 3, to obtain a first composite structure including the gallium oxide single-crystal wafer 1 and the high thermal conductivity substrate 2;

(11) 4) performing an annealing treatment on the first composite structure, as shown in FIG. 4, such that the first composite structure is peeled off along the implantation defect layer 11, thereby obtaining a second composite structure and a third composite structure, wherein the implantation defect layer 11 forms a first damaged layer 111 and a second damaged layer 112, the second composite structure includes the first damaged layer 111, the first gallium oxide layer 12 and the high thermal conductivity substrate 2, and the third composite structure includes the second damaged layer 112 and the second gallium oxide layer 13;

(12) 5) performing a surface treatment on the second composite structure to remove the first damaged layer 111, so as to obtain a gallium oxide semiconductor structure comprising the first gallium oxide layer 12 (also referred as gallium oxide single-crystal film) and the high thermal conductivity substrate 2, as shown in FIG. 5.

EXAMPLE 1

(13) A ?-type Sn-doped gallium oxide single-crystal wafer with a size of 10 mm?10 mm and a crystal orientation of (?201) was provided. H ion implantation was performed from the implantation surface, wherein the implantation energy was 30 keV, the implantation dose was 5?10.sup.17 ions/cm.sup.2, the implantation temperature was 30? C., and the implantation defect layer was formed at about 230 nm from the implantation surface. The implantation surface was directly bonded to a silicon oxide substrate. An annealing treatment was performed in N.sub.2 atmosphere, wherein the annealing temperature was 150? C., and the annealing time was 30 min. A chemical mechanical polishing was used to remove the damaged layer to obtain a gallium oxide semiconductor structure.

EXAMPLE 2

(14) A ?-type intrinsic wafer-scale gallium oxide wafer with a crystal orientation of (100) was provided. He ion implantation was performed from the implantation surface, wherein the implantation energy was 5 keV, the implantation dose was 1?10.sup.16 ions/cm.sup.2, the implantation temperature was ?20? C., and the implantation defect layer was formed at about 20 nm from the implantation surface. The implantation surface was bonded to a diamond substrate via anodic bonding. An annealing treatment was performed in He atmosphere, wherein the annealing temperature was 50? C., and the annealing time was 1 min. A chemical etching was used to remove the damaged layer to obtain a gallium oxide semiconductor structure.

EXAMPLE 3

(15) An ?-type iron (Fe) gallium oxide wafer-lever wafer with a crystal orientation of (001) was provided. H ion implantation and He ion implantation were performed from the implantation surface, wherein the implantation energy was 35 keV and 65 keV, the implantation dose was 1?10.sup.17 ions/cm.sup.22?10.sup.16 ions/cm.sup.2, the implantation temperature was 300? C., and the implantation defect layer was formed at about 230 nm from the implantation surface. The implantation surface was bonded to an aluminum nitride substrate via metal bonding. An annealing treatment was performed in O.sub.2 atmosphere, wherein the annealing temperature was 700? C., and the annealing time was 8 h. A plasma etching was used to remove the damaged layer to obtain a gallium oxide semiconductor structure.

EXAMPLE 4

(16) An ?-type intrinsic gallium oxide wafer-lever wafer with a crystal orientation of (?201) was provided. H ion implantation was performed from the implantation surface, wherein the implantation energy was 1000 keV, the implantation dose was 6?10.sup.17 ions/cm.sup.2, the implantation temperature was ?20? C., and the implantation defect layer was formed at about 20 ?m from the implantation surface. The implantation surface was directly bonded to a silicon carbide/silicon composite substrate. An annealing treatment was performed in air, wherein the annealing temperature was 700? C., and the annealing time was 24 h. A chemical mechanical polishing was used to remove the damaged layer to obtain a gallium oxide semiconductor structure.

(17) The foregoing description refers to preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Various changes can be made to the foregoing embodiments of the present invention. That is to say, all simple and equivalent changes and modifications made in accordance with the claims of the present invention and the content of the description fall into the protection scope of the patent of the present invention. What is not described in detail in the present invention is conventional technical content.