A silicon-based two-dimensional gallium nitride and its van der Waals epitaxial preparation method and application

Abstract

The present application relates to the technical field of inorganic semiconductor materials, and in particular to a silicon-based two-dimensional gallium nitride and its van der Waals epitaxial preparation method and application. The van der Waals epitaxial preparation method of silicon-based two-dimensional gallium nitride provided in the present application comprises: using gallium metal or gallium oxide as a gallium source, using urea as a nitrogen source, and using a silicon wafer with a van der Waals material on the surface as a growth substrate, and using a vapor deposition method to prepare a silicon-based two-dimensional gallium nitride material. The present application uses van der Waals epitaxial technology to prepare silicon-based two-dimensional gallium nitride on a van der Waals substrate by regulating growth parameters. The silicon-based two-dimensional gallium nitride has high crystal quality, good stability, low preparation cost, fast synthesis speed, and adjustable size and thickness. It can be used as a light detection component of a photodetector for ultraviolet detection.

Description

Technical Field

[0001] The present application relates to the technical field of inorganic semiconductor materials, and in particular to a silicon-based two-dimensional gallium nitride and a van der Waals epitaxial preparation method and application thereof. Background Art

[0002] The third-generation semiconductor material gallium nitride (GaN) has a wide direct band gap (3.4eV), stable physical and chemical properties, excellent luminous efficiency, high saturated electron drift velocity, high breakdown voltage and other properties. It can meet the requirements of high-frequency, high-temperature and high-power electronic devices. It is an ideal material for the development of high-efficiency light source devices (LED, LD, etc.), high-power transistors (HEMT, FET, etc.), photodetection devices (PDs, Sensors) and microwave communication devices (microwave oscillators, power amplifiers, etc.), and has great application prospects in microelectronics integration technology. Compared with bulk GaN materials, two-dimensional GaN has been proven to have a band gap width that can be widened to 5eV due to the quantum confinement effect, which is very suitable for deep ultraviolet photodetection. On the other hand, the two-dimensional thin layer structure of two-dimensional GaN is highly compatible with existing micro-nano processing technology, which is convenient for large-scale device integration and application in flexible devices. These characteristics have made two-dimensional GaN attract widespread attention. However, GaN has an intrinsic three-dimensional bond structure, and it is difficult to directly prepare the corresponding two-dimensional thin film structure by mechanical exfoliation or vapor deposition. In addition, existing growth techniques (such as molecular beam epitaxy and pulsed laser deposition) often require strict lattice matching between the epitaxial layer and the growth substrate. Therefore, the integrated application of GaN materials and silicon substrates still faces great challenges. Exploring the universal method of two-dimensional preparation of non-layered GaN materials and their integration with silicon substrates has important research significance and practical application value. Summary of the invention

[0003] The embodiment of the present application provides a van der Waals epitaxial preparation method for silicon-based two-dimensional gallium nitride, which solves the multi-physical mismatch limitation problems faced in two-dimensional gallium nitride silicon-based integration.

[0004] In a first aspect, the present application provides a van der Waals epitaxial preparation method for silicon-based two-dimensional gallium nitride, comprising: using gallium metal or gallium oxide as a gallium source, urea as a nitrogen source, and a silicon wafer with a van der Waals material on the surface as a growth substrate, and utilizing a vapor deposition method to prepare a silicon-based two-dimensional gallium nitride material.

[0005] In some embodiments, the preparation method comprises the following steps:

[0006] Prepare a van der Waals material on the surface of silicon wafer A to obtain a silicon wafer-van der Waals material composite substrate;

[0007] The gallium source is pressed onto the surface of silicon wafer B to obtain a metal gallium film, which is then left to stand to form a gallium oxide film;

[0008] The silicon wafer-van der Waals material composite substrate is inverted on top of the gallium oxide film, and then placed together in the rear temperature zone of a double-temperature zone tubular furnace. The nitrogen source is placed in the front temperature zone of the double-temperature zone tubular furnace, and heated in a hydrogen-argon mixed atmosphere for reaction for 10-60 minutes. After the reaction is completed, it is cooled to obtain a silicon-based two-dimensional gallium nitride material.

[0009] In some embodiments, the van der Waals material is selected from mica, boron nitride or graphite. In some preferred embodiments, the van der Waals material is selected from boron nitride.

[0010] In some embodiments, the temperature of the front temperature zone of the dual-zone tubular furnace is set to 130-180° C., and the temperature of the rear temperature zone of the dual-zone tubular furnace is set to 800-1050° C. In some preferred embodiments, the temperature of the front temperature zone of the dual-zone tubular furnace is set to 160° C., and the temperature of the rear temperature zone of the dual-zone tubular furnace is set to 950° C.

[0011] In some embodiments, the thickness of the van der Waals material is 0.3-100 nm. In some preferred embodiments, the thickness of the van der Waals material is 1-20 nm.

[0012] In some embodiments, the flow rate of hydrogen is 10-50 sccm, and the flow rate of argon is 40-200 sccm. In some preferred embodiments, the flow rate of hydrogen is 20 sccm, and the flow rate of argon is 100 sccm.

[0013] In some embodiments, the distance between the silicon wafer-van der Waals material composite substrate and the gallium oxide film is 0.3-3 mm. In some preferred embodiments, the distance between the silicon wafer-van der Waals material composite substrate and the gallium oxide film is 0.5 mm.

[0014] In some embodiments, the van der Waals material is prepared on the surface of the silicon wafer A by mechanical stripping or vapor deposition.

[0015] In a second aspect, the present application also provides a silicon-based two-dimensional gallium nitride material prepared using the above-mentioned preparation method. The band gap of the two-dimensional gallium nitride material is distributed in the ultraviolet region of 3.6-5eV and can be used as an active region of an ultraviolet detector.

[0016] In a third aspect, the present application also provides an application of the above-mentioned silicon-based two-dimensional gallium nitride material, wherein the two-dimensional gallium nitride material is used to prepare a photodetector.

[0017] In some embodiments, an electrode pattern is produced on silicon-based two-dimensional gallium nitride using a photolithography or electron beam exposure process, and a silicon-based two-dimensional gallium nitride photodetector is produced using a metal coating process.

[0018] The silicon-based two-dimensional gallium nitride prepared in this application has the following two significant characteristics: First, the growth methods adopted in the preparation process of this application are all vapor deposition methods, the growth substrates adopted in the preparation process are all van der Waals substrates or silicon wafers with van der Waals materials on the surface, and the growth modes adopted in the preparation process are all van der Waals epitaxial growth modes. Different from traditional epitaxial technology (such as molecular beam epitaxy), van der Waals epitaxy does not require strict matching of the growth substrate and the lattice of the epitaxial material, and the lattice arrangement can also be quite different. The surface of the substrate without dangling bonds and the epitaxial layer interact through weak van der Waals forces, which can effectively reduce the interface stress effect, reduce interface defects, dislocations and other undesirable factors, and solve the multi-physical mismatch limitation problems faced in the silicon-based integration of non-layered gallium nitride materials, thereby realizing its silicon-based integration. Second, the obtained silicon-based two-dimensional gallium nitride material has high crystal quality, good stability, and adjustable size and thickness. It can be used as a light detection component of a photodetector for ultraviolet detection.

[0019] The beneficial effects of the technical solution provided by this application include:

[0020] 1. This application uses van der Waals epitaxy technology to prepare silicon-based two-dimensional gallium nitride on a van der Waals substrate by adjusting growth parameters. It has high crystal quality, good stability, low preparation cost, fast synthesis speed, and adjustable size and thickness. It can be used as a light detection component of a photodetector for ultraviolet detection;

[0021] 2. This application introduces van der Waals materials into the surface of silicon wafers as a lattice mismatch buffer layer, which effectively reduces the interface stress effect, reduces interface defects, dislocations and other adverse factors, and solves the multi-physical mismatch limitation problems faced in two-dimensional gallium nitride silicon-based integration, thereby realizing its silicon-based integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a schematic diagram of preparing silicon-based two-dimensional gallium nitride in a dual-temperature zone tube furnace in the present application;

[0024] Figure 2 This is an optical microscope observation result diagram of silicon-based two-dimensional gallium nitride obtained in Example 1 of the present application;

[0025] Figure 3 This is a scanning electron microscope observation result diagram of silicon-based two-dimensional gallium nitride obtained in Example 2 of the present application;

[0026] Figure 4 The high-resolution transmission electron microscopy image and selected area electron diffraction image of silicon-based two-dimensional gallium nitride provided in Example 2 of the present application;

[0027] Figure 5 This is the Raman spectrum of silicon-based two-dimensional gallium nitride obtained in Example 2 of the present application;

[0028] Figure 6 This is a diagram of the optical switching change of the silicon-based two-dimensional gallium nitride photodetector provided in Example 2 of the present application under 360nm incident laser. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0030] The embodiment of the present application provides a van der Waals epitaxial preparation method of silicon-based two-dimensional gallium nitride, which can solve the multiple physical mismatch limitation problems faced in the two-dimensional gallium nitride silicon-based integration.

[0031] The present application provides a method for preparing two-dimensional gallium nitride on silicon by van der Waals epitaxy, comprising the following steps:

[0032] Step S101, preparing a van der Waals material on the surface of silicon wafer A by mechanical stripping or vapor deposition to obtain a silicon wafer-van der Waals material composite substrate; the van der Waals material is selected from mica, boron nitride or graphite; the thickness of the van der Waals material is 0.3-100 nm;

[0033] Step S102, imprinting a gallium source on the surface of silicon wafer B to obtain a metal gallium film, and letting it stand to form a gallium oxide film; the gallium source is gallium metal or gallium oxide;

[0034] Step S103, invert the silicon wafer-van der Waals material composite substrate on top of the gallium oxide film, and then place them together in the rear temperature zone of the double-temperature zone tubular furnace, place the nitrogen source in the front temperature zone of the double-temperature zone tubular furnace, heat and react for 10-60 minutes in a mixed atmosphere of hydrogen and argon, and cool after the reaction to obtain a silicon-based two-dimensional gallium nitride material. The silicon-based two-dimensional gallium nitride material has a lateral size of 2-50 μm and a thickness of 5-100 nm; wherein the silicon wafer-van der Waals material composite substrate and the gallium oxide film are spaced 0.3-3 mm apart, the temperature of the front temperature zone of the double-temperature zone tubular furnace is set to 130-180°C, and the temperature of the rear temperature zone of the double-temperature zone tubular furnace is set to 800-1050°C; the flow rate of hydrogen is 10-50 sccm, and the flow rate of argon is 40-200 sccm.

[0035] Schematic diagram of preparing silicon-based two-dimensional gallium nitride materials in a dual-temperature zone tube furnace. Figure 1 .

[0036] The silicon-based two-dimensional gallium nitride and the van der Waals epitaxial preparation method thereof provided by the present application are described in detail below in conjunction with the embodiments.

[0037] Embodiment 1:

[0038] Embodiment 1 provides a method for preparing two-dimensional gallium nitride on silicon by van der Waals epitaxy, comprising the following steps:

[0039] Step S101, preparing a layer of boron nitride film as a lattice mismatch buffer layer on a substrate of silicon wafer A by vapor deposition to form a silicon wafer-boron nitride composite substrate;

[0040] Step S102, imprinting liquid metal gallium on the surface of another silicon wafer B to obtain a metal gallium film, and placing the metal gallium film in the air for 3 hours to spontaneously transform it into a gallium oxide film;

[0041] Step S103, invert the silicon wafer-boron nitride composite substrate right above the gallium oxide film, so that the silicon wafer-boron nitride composite substrate and the gallium oxide film are placed face to face with a spacing of 0.5 mm; then place the silicon wafer-boron nitride composite substrate and the gallium oxide film together in the rear temperature zone of the double-temperature zone tubular furnace, the temperature of the rear temperature zone is set to 980°C, and place 5g of urea powder in the front temperature zone of the double-temperature zone tubular furnace, and the temperature of the front temperature zone is set to 160°C; introduce hydrogen-argon mixed gas (20sccm hydrogen and 100sccm argon) as carrier gas into the double-temperature zone tubular furnace, grow for 30 minutes, and then naturally cool to room temperature, that is, obtain silicon-based two-dimensional gallium nitride material on the surface of the silicon wafer-boron nitride composite substrate, and realize the controllable preparation of silicon-based two-dimensional gallium nitride.

[0042] The electrode pattern is made on the silicon-based two-dimensional gallium nitride using the photolithography process, and the two-dimensional gallium nitride photodetector is made using the metal coating process.

[0043] Figure 2 This is an optical microscope observation result of silicon-based two-dimensional gallium nitride obtained in Example 1 of the present application. Figure 2 It can be seen that the silicon-based two-dimensional gallium nitride synthesized in Example 1 is hexagonal.

[0044] Embodiment 2:

[0045] Embodiment 2 provides a method for preparing two-dimensional gallium nitride on silicon by van der Waals epitaxy, comprising the following steps:

[0046] Step S101, preparing mica on the surface of silicon wafer A by mechanical exfoliation as a lattice mismatch buffer layer to form a silicon wafer-mica composite substrate;

[0047] Step S102, imprinting liquid metal gallium on the surface of another silicon wafer B to obtain a metal gallium film, heating the metal gallium film to 300° C. in air and maintaining it for 1 hour to accelerate the formation of a gallium oxide film;

[0048] Step S103, invert the silicon wafer-mica composite substrate right above the gallium oxide film, so that the silicon wafer-mica composite substrate and the gallium oxide film are placed face to face with a spacing of 0.3 mm; place the above-mentioned silicon wafer-mica composite substrate and the gallium oxide film together in the rear temperature zone of a double-temperature zone tubular furnace, and the temperature of the rear temperature zone is set to 950°C; place 3g of urea powder in the front temperature zone of the double-temperature zone tubular furnace, and the temperature of the front temperature zone is set to 150°C; introduce a hydrogen-argon mixed gas (30sccm hydrogen and 80sccm argon) as a carrier gas into the tubular furnace, grow for 20 minutes, and then naturally cool to room temperature, that is, obtain silicon-based two-dimensional gallium nitride material on the surface of the silicon wafer-mica composite substrate, and realize the controllable preparation of silicon-based two-dimensional gallium nitride.

[0049] The electrode pattern is made on the silicon-based two-dimensional gallium nitride using the photolithography process, and the two-dimensional gallium nitride photodetector is made using the metal coating process. The optoelectronic application performance is detected using a laser with a wavelength of 360nm.

[0050] Figure 3 is a scanning electron microscope observation result diagram of silicon-based two-dimensional gallium nitride obtained in Example 2 of the present application, Figure 3 It can be seen that the two-dimensional gallium nitride synthesized in Example 2 is in the shape of hexagons and triangles.

[0051] Figure 4 The high-resolution transmission electron microscopy image and selected area electron diffraction image of silicon-based two-dimensional gallium nitride provided in Example 2 of the present application are Figure 4 It can be seen that the synthesized two-dimensional gallium nitride lattice stripes and selected area diffraction spots are very clear and have very good crystallinity.

[0052] Figure 5 is the Raman spectrum of silicon-based two-dimensional gallium nitride obtained in Example 2 of the present application, Figure 5 It can be seen that the two-dimensional gallium nitride has two characteristic peaks: E 2 (High) and A 1 (LO), it was determined that the composition of the synthesized 2D material was gallium nitride.

[0053] Figure 6 The light switching change diagram of the silicon-based two-dimensional gallium nitride photodetector provided in Example 2 of the present application under 360nm incident laser, from Figure 6 It can be seen that there is an obvious switching current and it does not decay over time, indicating that the two-dimensional gallium nitride photodetector has the ability to detect in the ultraviolet band and has good stability.

[0054] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0055] It should be noted that, in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically stipulated.

[0056] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing two-dimensional gallium nitride on silicon by van der Waals epitaxy, characterized in that: include: Using gallium metal or gallium oxide as a gallium source, urea as a nitrogen source, and a silicon wafer with a van der Waals material on the surface as a growth substrate, a silicon-based two-dimensional gallium nitride material is prepared by a vapor deposition method; The preparation method comprises the following steps: Prepare a van der Waals material on the surface of silicon wafer A to obtain a silicon wafer-van der Waals material composite substrate; The gallium source is pressed onto the surface of silicon wafer B to obtain a metal gallium film, which is then left to stand to form a gallium oxide film; The silicon wafer-van der Waals material composite substrate is placed upside down on the gallium oxide film, and then placed together in the rear temperature zone of a double-temperature zone tubular furnace. The nitrogen source is placed in the front temperature zone of the double-temperature zone tubular furnace, and heated in a hydrogen-argon mixed atmosphere for reaction. After the reaction is completed, it is cooled to obtain a silicon-based two-dimensional gallium nitride material; The van der Waals material is selected from any one of mica, boron nitride or graphite; The temperature of the front temperature zone of the double temperature zone tubular furnace is set to 130-180°C, and the temperature of the rear temperature zone of the double temperature zone tubular furnace is set to 800-1050°C; The flow rate of hydrogen is 10-50sccm, and the flow rate of argon is 40-200sccm; The distance between the silicon wafer-van der Waals material composite substrate and the gallium oxide film is 0.3-3 mm.

2. The van der Waals epitaxial preparation method of silicon-based two-dimensional gallium nitride according to claim 1, characterized in that: The thickness of the van der Waals material is 0.3-100 nm.

3. The van der Waals epitaxial preparation method of silicon-based two-dimensional gallium nitride according to claim 1, characterized in that: The van der Waals material is prepared on the surface of the silicon wafer A by a mechanical stripping method or a vapor deposition method.

4. A silicon-based two-dimensional gallium nitride, characterized in that: The method according to claim 1 is used to prepare the present invention.

5. The use of silicon-based two-dimensional gallium nitride according to claim 4, characterized in that: The silicon-based two-dimensional gallium nitride is used to prepare a photodetector.

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