Multi-Layer Semiconductor Material Structure and Preparation Method Thereof

Abstract

The present disclosure relates to the technical field of semiconductors. Disclosed is a multi-layer semiconductor material structure and a preparation method thereof, solving the problems of the existing semiconductor materials that have poor heat dissipation, high cost, and cannot be mass-produced. The multi-layer semiconductor material structure includes a highly thermally conductive support substrate and a crystallized device function layer, where the device function layer is provided on the highly thermally conductive support substrate, and has a single-crystal surface layer.

Claims

1-10. (canceled)

11. A multi-layer semiconductor material structure, comprising: a highly thermally conductive support substrate, and a crystallized device function layer comprising a single-crystal surface layer, wherein the crystallized device function layer is provided on the highly thermally conductive support substrate.

12. The multi-layer semiconductor material structure of claim 11, wherein the device function comprises has a crystal structure, with a microstructural gradient from single-crystal to poly-crystal from a surface to an interface.

13. The multi-layer semiconductor material structure of claim 11, wherein the device function layer is a single-layer structure comprises at least one selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN, and has a thickness of 100 nm to 50 .Math.m.

14. The multi-layer semiconductor material structure of claim 11, wherein the device function layer comprises a first film layer and a second film layer; wherein the first film layer is provided on the highly thermally conductive support substrate; and wherein the second film layer is provided on the first film layer; the first film layer is a single-layer structure comprising at least one selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN, SiN, SiO.sub.2, HfO.sub.2, SiNO, SiCO, and AlON; wherein the first film layer has a thickness of 100 nm to 50 .Math.m; and wherein the second film layer is a single-layer structure comprises at least one selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN; and wherein the second film layer has a thickness of 100 nm to 50 .Math.m.

15. The multi-layer semiconductor material structure according to claim 11, wherein the highly thermally conductive support substrate comprises at least one selected from the group consisting of diamond, SiC, AlN, BN, BeO, AlSiC, CuW, and CuMo.

16. The multi-layer semiconductor material structure according to claim 11, wherein the device function layer has a crystal structure, with a single-crystal portion close to the surface and the interface, and a microstructural gradient from single-crystal to poly-crystal from the surface and the interface to a center.

17. The multi-layer semiconductor material structure according to claim 11, wherein the device function layer comprises a first film layer and a second film layer; wherein the first film layer is provided on the highly thermally conductive support substrate; and the second film layer is provided on the first film layer; the first film layer is a single-layer structure comprising at least one selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN, SiN, SiO.sub.2, HfO.sub.2, SiNO, SiCO, and AlON; the second film layer is a single-layer structure made of a multi-layer structure made of more of the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN; wherein the first and second film layers each have a thickness within the range of 100 nm to 50 .Math.m.

18. The multi-layer semiconductor material structure according to claim 11, wherein the device function layer comprises a first film layer and a second film layer; wherein the first film layer is provided on the highly thermally conductive support substrate; and the second film layer is provided on the first film layer; wherein the first film layer is a single-layer structure made of a multi-layer structure comprising at least selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN, SiN, SiO.sub.2, HfO.sub.2, SiNO, SiCO, and AlON; and the first film layer has a thickness within the range of 100 nm to 50 .Math.m; and wherein the second film layer is a single-layer structure comprises at least one selected from the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN; and the second film layer has a thickness within the range of 100 nm to 50 .Math.m.

19. The multi-layer semiconductor material structure according to claim 11, wherein the device function layer comprises a first film layer and a second film layer; wherein the first film layer is provided on the highly thermally conductive support substrate; and the second film layer is provided on the first film layer; wherein the first film layer is a single-layer structure made of a multi-layer structure made of more of the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN, SiN, SiO.sub.2, HfO.sub.2, SiNO, SiCO, and AlON; and the first film layer has a thickness within the range of 100 nm to 50 .Math.m; and wherein the second film layer is a single-layer structure made of a multi-layer structure made of more of the group consisting of gallium oxide, silicon, silicon carbide, GaN, aluminum oxide, germanium, carbon, AlN, ZnO, GaAs, AlGaN; and the second film layer has a thickness within the range of 100 nm to 50 .Math.m.

20. A method of preparing a multi-layer semiconductor material structure, comprising: forming a device function layer on a highly thermally conductive support substrate; attaching a single-crystal substrate to a surface of the device function layer; annealing at 300-1,800° C.; and lifting the single-crystal substrate off after cooling to obtain the multi-layer semiconductor material structure.

21. The method of claim 20, wherein the device function layer is formed on the highly thermally conductive support substrate by at least one of chemical vapor deposition, atomic layer deposition, molecular beam deposition, HVPE, physical sputtering, and plasma-enhanced chemical vapor deposition.

22. The method of claim 20, wherein the device function layer comprises a first film layer and a second film layer; and wherein forming a device function layer comprises: depositing the first film layer with a thickness within the range of 100 nm to 50 .Math.m on the highly thermally conductive support substrate; planarizing and smoothing the first film layer; and depositing the second film layer with a thickness within the range of 100 nm to 50 .Math.m.

23. The method of claim 20, wherein the device function layer is a single film layer with a thickness within the range of 100-50 .Math.m; and the preparation method further comprises: planarizing and smoothing the film layer after forming the film layer on the highly thermally conductive support substrate, and attaching a single-crystal substrate to a surface of the smoothed film layer.

24. The method of claim 20, wherein the device function layer is planarized and smoothed to a surface roughness within the range of 0.1-10 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are provided merely for illustrating specific examples and are not considered as limiting the present application. The same reference numerals denote the same components throughout the drawings.

[0035] FIG. 1 is a schematic diagram of a highly thermally conductive support substrate;

[0036] FIG. 2 is a flowchart of a preparation method of a multi-layer semiconductor material structure according to an embodiment;

[0037] FIG. 3 is a flowchart of a preparation method of a multi-layer semiconductor material structure according to another embodiment;

[0038] FIG. 4 is a flowchart of a preparation method of a multi-layer semiconductor material structure according to another embodiment;

[0039] FIG. 5 is a flowchart of film layer crystallization;

[0040] FIG. 6 is a sectional diagram of a multi-layer semiconductor material structure after patterning and etching;

[0041] FIG. 7 is a sectional diagram of another multi-layer semiconductor material structure after patterning and etching;

[0042] FIG. 8 is a sectional diagram of another multi-layer semiconductor material structure after patterning and etching; and

[0043] FIG. 9 is a plan view of a multi-layer semiconductor material structure after patterning and etching.

REFERENCE NUMERALS

[0044] 1. highly thermally conductive support substrate; 101. first surface; 102. second surface; 2. device function layer; 201. first film layer; 202. second film layer; and 3. single-crystal substrate.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The embodiments of the present application are described below with reference to the drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present application. In addition, in the following description, descriptions of conventional structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present application.

[0046] Various schematic diagrams of the embodiments of the present application are illustrated in the drawings. These drawings are not drawn to scale, in which some details are enlarged to be seen clearly, and some details may be omitted. The shapes of various regions and layers shown in the drawings and relative sizes and positional relationships thereof are merely exemplary, which may be different due to manufacturing tolerances or technical limitations in practice, and those skilled in the art may additionally design regions/layers with different shapes, sizes and relative positions according to actual needs.

[0047] In the context of the present application, when a layer/element is referred to as being “on” another layer/element, it may be directly on the another layer/element, or there may be an intermediate layer/element present there-between. In addition, if a layer/element is “on” another layer/element in one orientation, the layer/element may be “under” the another layer/element when the orientation is reversed.

[0048] A multi-layer semiconductor material structure includes a highly thermally conductive support substrate 1 and a crystallized device function layer 2. The device function layer 2 is provided on the highly thermally conductive support substrate 1, and a near-surface layer of the device function layer 2 has a single-crystal structure.

[0049] A crystal structure of the crystallized device function layer 2 has a microstructural gradient from single-crystal to poly-crystal from a surface to an interface. A surface layer portion near the surface has a high-quality single-crystal structure and has a fixed orientation, such as [0001], [001], [111], [110], etc.

[0050] Compared with the prior art, in the present application, the device function layer 2 of the multi-layer semiconductor material structure is provided on the highly thermally conductive support substrate 1. The device function layer 2 is a film layer that is at least partially crystallized, and the near-surface layer of the device function layer 2 has a single-crystal structure. The multi-layer semiconductor material structure of the present application forms a highly thermally conductive interface, which improves the heat dissipation efficiency of the device function layer 2, and ensures the practicability of the device function layer 2. Therefore, the multi-layer semiconductor material structure can be used for device fabrication.

[0051] Specifically, the highly thermally conductive support substrate 1 (with a thermal conductivity greater than 100 W/m•K) is made of at least one of the group consisting of diamond, silicon carbide (SiC), aluminum nitride (AlN), boron nitride (BN), beryllium oxide (BeO), aluminum silicon carbide (AlSiC), copper tungsten (CuW), and copper molybdenum (CuMo). Its crystal form and crystal orientation are not limited, and it may be single-crystal, poly-crystal, or amorphous.

[0052] When the highly thermally conductive support substrate 1 is single-crystal, the device function layer 2 has a crystal structure, with a single-crystal portion close to the surface and the interface, and a microstructural gradient from single-crystal to poly-crystal from the surface and the interface to a center.

[0053] As shown in FIG. 1, the highly thermally conductive support substrate 1 includes a first surface 101 and a second surface 102. The first surface 101 has a roughness of less than 1000 nm. If the first surface is too rough, it will result in high cost of a subsequent process. Preferably, the second surface 102 has a roughness of 1 nm to 20 .Math.m.

[0054] In an embodiment of the present application, the device function layer 2 is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), and aluminum gallium nitride (AlGaN).

[0055] In another embodiment of the present application, in order to enhance the interfacial adsorption force, release stress and thermal conductivity, the device function layer 2 includes a first film layer 201 and a second film layer 202. The first film layer 201 has a thermal expansion coefficient closer to that of the highly thermally conductive support substrate 1 and a higher chemical affinity. It is provided on the highly thermally conductive support substrate 1, and has a thickness of 100 nm to 50 .Math.m. The second film layer 202 is provided on the first film layer 201, and has a thickness of 100 nm to 50 .Math.m. The first film layer 201 is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), aluminum gallium nitride (AlGaN), silicon nitride (SiN), silicon dioxide (SiO.sub.2), hafnium oxide (HfO.sub.2), silicon oxynitride (SiNO), silicon oxycarbide (SiCO), and aluminum oxynitride (AlON), or a multi-layer structure formed by depositing more of the group separately. The second film layer 202 is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), and aluminum gallium nitride (AlGaN), or a multi-layer structure formed by depositing more of the group separately.

[0056] The present application further provides a preparation method of a multi-layer semiconductor material structure, including the following steps:

[0057] Form a device function layer 2 on a highly thermally conductive support substrate 1.

[0058] Attach a single-crystal substrate 3 to a surface of the device function layer 2.

[0059] Anneal.

[0060] Lift the single-crystal substrate 3 off after cooling to obtain the multi-layer semiconductor material structure.

[0061] As shown in FIG. 5, in the present application, the single-crystal substrate 3 with a low defect density is attached to the surface of the device function layer 2 as an initial nucleation substrate. Then, heating and annealing are performed. A surface layer of the device function layer 2 undergoes solid-phase epitaxial crystallization along a surface of the initial nucleation substrate, with an orientation consistent with that of the initial nucleation substrate. After cooling, the initial nucleation substrate (i.e. the single-crystal substrate 3) is lifted off. The crystal structure of the crystallized device function layer 2 has a microstructural gradient from single-crystal to poly-crystal from a surface to an interface, and a near-surface layer has a high-quality single-crystal structure. The preparation method of the present application is simple. The single-crystal structure is formed on the surface layer of the device function layer 2, which ensures the practicability of the device function layer 2, and can be used for device fabrication.

[0062] When the highly thermally conductive support substrate 1 is single-crystal, the same nucleation effect as the single-crystal substrate 3 attached to the surface of the device function layer 2 will be produced during annealing. At this time, the device function layer 2 has a crystal structure, with a single-crystal portion of the device function layer 2 close to the surface and the interface, and a microstructural gradient from single-crystal to poly-crystal from the surface and the interface to a center.

[0063] Exemplarily, the single-crystal substrate 3 may be made of sapphire. The single-crystal substrate 3 has a thickness of 50-1,000 .Math.m and a surface roughness of 0.1-10 nm to ensure full contact with the surface of the device function layer 2.

[0064] The device function layer 2 is formed on the highly thermally conductive support substrate 1 by at least one means of chemical vapor deposition (CVD), atomic layer deposition (ALD), molecular beam deposition (MBD), hydride vapor phase epitaxy (HVPE), physical sputtering, and plasma-enhanced chemical vapor deposition (PECVD).

[0065] Before attaching the single-crystal substrate 3, the device function layer 2 is planarized and smoothed such that the surface roughness of the device function layer 2 is 0.1 -10 nm. Specifically, the planarization and smoothing are performed by chemical mechanical polishing (CMP) and plasma treatment.

[0066] The annealing temperature is 300-1,800° C. In order to prevent a high thermal stress produced during annealing, the heating and annealing rates are not higher than 50° C. /min, and the holding time is 5-100 min.

[0067] In an embodiment of the present application, as shown in FIG. 2, a highly thermally conductive support substrate 1 is first provided. The device function layer 2 is deposited on a first surface 101 of the highly thermally conductive support substrate 1. It is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), and aluminum gallium nitride (AlGaN). The device function layer has a thickness of 100 nm to 50 .Math.m, and has an amorphous structure. The device function layer is planarized and smoothed such that its surface roughness is 0.1-10 nm, and the thickness after planarization and smoothing is 50 nm to 45 .Math.m. Then annealing is performed to crystallize the device function layer.

[0068] In another embodiment of the present application, as shown in FIG. 3, in order to enhance the interfacial adsorption force, release stress and thermal conductivity, another multi-layer structure is adopted. The device function layer 2 includes a first film layer 201 and a second film layer 202. First, a highly thermally conductive support substrate 1 is provided, and the first film layer 201 is deposited on the first surface 101 of the highly thermally conductive support substrate 1. The first film layer 201 is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), aluminum gallium nitride (AlGaN), silicon nitride (SiN), silicon dioxide (SiO.sub.2), hafnium oxide (HfO.sub.2), silicon oxynitride (SiNO), silicon oxycarbide (SiCO), and aluminum oxynitride (AlON), or a multi-layer structure formed by depositing more of the group separately. The first film layer 201 has a thickness of 100 nm to 50 .Math.m, and has an amorphous structure. The first film layer is planarized and smoothed to a surface roughness of 0.1-50 nm. Then, the second film layer 202 is deposited and surface-smoothed. The second film layer 202 is a single-layer structure made of one of the group consisting of gallium oxide (Ga.sub.2O.sub.3), silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminum oxide (Al.sub.2O.sub.3), germanium (Ge), carbon (C), aluminum nitride (AlN), zinc oxide (ZnO), gallium arsenide (GaAs), and aluminum gallium nitride (AlGaN), or a multi-layer structure formed by depositing more of the group separately. The second film layer has a thickness of 100 nm to 50 .Math.m and a surface roughness of 0.1-10 nm. The second film layer is then annealed to crystallize. The crystallized thin structure has a microstructural gradient from single-crystal to poly-crystal from a surface to an interface, and a near-surface layer has a high-quality single-crystal structure and a fixed orientation, such as [0001], [001], [111], [110], etc.

[0069] In another embodiment of the present application, as shown in FIG. 4, similarly, the device function layer includes a first film layer 201 and a second film layer 202. After the first film layer 201 is deposited, the planarization and smoothing steps are omitted, and the second film layer 202 is directly deposited. The second film layer 202 is then planarized and smoothed.

[0070] The prepared multi-layer semiconductor material structure may also have a patterned and etched structure from the above structure. Possible sections are shown in FIGS. 6 to 8. A possible plan view is shown in FIG. 9, but it is not limited to a circular substrate and square patches.

Embodiment 1

[0071] First, a highly thermally conductive support substrate 1 is provided, which is made of diamond and has a thickness of 100-200 .Math.m. A first surface 101 has a roughness of 1 nm, and a second surface 102 has a roughness of 20 nm.

[0072] A gallium oxide (Ga.sub.2O.sub.3) layer is deposited on the highly thermally conductive support substrate 1 by means of CVD, and it has a thickness of 200 nm.

[0073] The gallium oxide (Ga.sub.2O.sub.3) layer is planarized and smoothed to a roughness of 0.5 nm.

[0074] A sapphire single-crystal substrate 3 is attached on the planarized and smoothed gallium oxide (Ga.sub.2O.sub.3) layer. The single-crystal substrate 3 has a thickness of 500 .Math.m and a roughness of 0.3 nm. Then, heating and annealing are performed. Specifically, the temperature is raised to 600° C. at a rate of 1° C. /min, held for 30 min, and dropped at a rate of 1° C. /min. After cooling, the single-crystal substrate 3 is removed to obtain a multi-layer semiconductor material structure.

Embodiment 2

[0075] First, a highly thermally conductive support substrate 1 is provided, which is made of silicon carbide (SiC) and has a thickness 400 .Math.m. A first surface 101 has a roughness of 0.3 nm, and a second surface 102 has a roughness of 10 nm.

[0076] An aluminum oxide (Al.sub.2O.sub.3) layer is deposited on the highly thermally conductive support substrate 1 by means of ALD, and it has a thickness of 100 nm.

[0077] A gallium oxide (Ga.sub.2O.sub.3) layer is deposited on the aluminum oxide (Al.sub.2O.sub.3) layer by means of CVD, and it has a thickness of 200 nm. The gallium oxide (Ga.sub.2O.sub.3) layer is planarized and smoothed to a roughness of 0.5 nm.

[0078] A single-crystal aluminum oxide (Al.sub.2O.sub.3) substrate is attached on the gallium oxide (Ga.sub.2O.sub.3) layer. The single-crystal substrate 3 has a thickness of 50 .Math.m roughness of 0.3 nm. Then, heating and annealing are performed. Specifically, the temperature is raised to 600° C. at a rate of 1° C. /min, held for 30 min, and dropped at a rate of 1° C. /min. After cooling, the single-crystal substrate 3 is removed to obtain a multi-layer semiconductor material structure.

[0079] In the above description, the technical details such as the composition and etching of each layer are not described in detail. However, those skilled in the art should understand that layers and regions with desired shapes can be formed by various technical means. In addition, in order to form the same structure, those skilled in the art can also design a method that is not completely the same as the method described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination.

[0080] The embodiments of the present application are described above. However, these embodiments are for illustrative purposes only, and are not intended to limit the scope of the present application. The scope of the present application is limited by the appended claims and legal equivalents thereof. Those skilled in the art can make various substitutions and modifications to the present application without departing from the scope of the present application, but such substitutions and modifications should all fall within the scope of the present application.