CN111341836A - Graphene intermediate layer flexible substrate for heteroepitaxy and preparation method thereof - Google Patents

Abstract

The present disclosure provides a graphene intermediate layer flexible substrate for heteroepitaxy and a preparation method thereof. The graphene intermediate layer flexible substrate used for heteroepitaxy includes, from bottom to top, a support layer and a A buffer layer, the buffer layer sequentially includes: at least one graphene buffer layer and at least one metal film buffer layer from bottom to top. In the present disclosure, by using the buffer layer structure of the combination of the graphene buffer layer and the metal film buffer layer, the advantages of small lattice adaptation of graphene are rationally utilized, and under the protection of the metal film buffer layer, the graphene can be prevented from being etched during the preparation process. It is beneficial to improve the quality of single crystal diamond heteroepitaxy, so as to realize the heteroepitaxial growth of large-area and high-quality diamond film layer.

Description

Graphene intermediate layer flexible substrate for heteroepitaxy and preparation method thereof

technical field

The present disclosure relates to the field of semiconductor material preparation, in particular to a graphene intermediate layer flexible substrate for heteroepitaxy and a preparation method thereof.

Background technique

As a third-generation semiconductor material, diamond has the advantages of large band gap, high thermal conductivity, high electron saturation drift speed, good thermal and chemical stability, radiation resistance and corrosion resistance. It is currently the most promising third-generation semiconductor material. Generation of semiconductor materials. As a semiconductor material, diamond can be used as heat sinks, high temperature, high pressure and high frequency field effect diodes, ultraviolet light detectors, radiation detectors, etc.

Polycrystalline diamond is mostly used for auxiliary applications such as heat sinks and packaging, while single crystal diamond has a wider range of applications in the composition of semiconductor devices. Small-area diamond epitaxial films have relatively narrow applications, and only large-area, high-quality single-crystal diamonds can be used more widely, meeting the requirements of scale, integration, and standardization of semiconductor materials. Therefore, large-area high-quality single crystal diamond has a strong market demand and application potential.

Because microwave plasma chemical vapor deposition has the following advantages: (1) no internal electrode to avoid the pollution caused by the electrode; (2) the working parameters can be easily controlled; (3) the working pressure is wide, the plasma density is high, and the energy conversion rate is high. Recognized as the best way to obtain device-grade single crystal diamond material, it can grow diamond on homogeneous or heterogeneous substrates. However, homoepitaxy is limited by the size of the diamond substrate and the cost of epitaxy is high. Therefore, the use of large-area substrates for heteroepitaxy is the best way to prepare large-area high-quality single-crystal diamonds, and thus has received more and more attention.

In terms of heteroepitaxial growth, some achievements have been made, especially on Ir substrates. However, the quality of heteroepitaxial single crystal is still lower than that of homoepitaxial, and the main problem is the problem of lattice matching. The lattice mismatch ratio of diamond and graphene is only 2.6%, so graphene is very suitable as a heteroepitaxial substrate for single crystal diamond.

According to the above introduction, it is speculated that diamond can be directly epitaxial on graphene by microwave plasma chemical vapor deposition, but there are few related existing technologies. The reason is that the graphene exposed to the plasma environment is easily etched away, and the graphene phase can only exist under certain MPCVD working conditions, but the graphene defects are greatly increased due to the bombardment of the plasma. As a result, it is difficult to grow diamond single crystals on graphene by microwave plasma chemical vapor deposition, which deviates from the original intention of introducing the graphene layer.

SUMMARY OF THE INVENTION

(1) Technical problems to be solved

The present disclosure provides a graphene intermediate layer flexible substrate for heteroepitaxy and a preparation method thereof to at least partially solve the above technical problems.

(2) Technical solutions

According to one aspect of the present disclosure, there is provided a graphene intermediate layer flexible substrate for heteroepitaxy, comprising in order from bottom to top: a support layer and a buffer layer, the buffer layer comprising in order from bottom to top : at least one graphene buffer layer and at least one metal film buffer layer.

In some embodiments of the present disclosure, the graphene buffer layer has a thickness of 1-50 atomic layers.

In some embodiments of the present disclosure, the thickness of the metal film buffer layer is 2˜100 nm.

In some embodiments of the present disclosure, the material of the metal film buffer layer is one or more of Pt, Ir, and Cu.

In some embodiments of the present disclosure, the material of the support layer is any one of silicon carbide, silicon, sapphire, quartz, glass and metal as a single material or a composite material of any one.

According to an aspect of the present disclosure, there is also provided a method for preparing a graphene intermediate flexible substrate for heteroepitaxy as described above, comprising the steps of:

S1. Surface treatment of the support layer to remove organic and inorganic chemical pollutants on the surface of the support layer;

S2, placing the support layer after the surface treatment in step S1 in a reaction chamber, the gas atmosphere is one or more of argon and hydrogen, the temperature range is 1500-1700°C, and the pressure range in the reaction chamber is 1 ~700 Torr, a graphene buffer layer is prepared on the upper surface of the support layer;

S3, using magnetron sputtering to prepare a metal film buffer layer on the graphene buffer layer prepared in step S2.

In some embodiments of the present disclosure, in the step S1, standard RCA cleaning is selected to perform surface treatment on the support layer.

In some embodiments of the present disclosure, the growth time of the support layer in the reaction chamber in the step S2 is 5-120 min.

(3) Beneficial effects

As can be seen from the above technical solutions, the graphene intermediate layer flexible substrate for heteroepitaxy and the preparation method thereof of the present disclosure have at least one or a part of the following beneficial effects:

The arrangement of the graphene buffer layer and the metal film buffer layer disclosed in the present disclosure reasonably utilizes the advantages of small lattice adaptation of graphene, and under the protection of the metal film buffer layer, the graphene can be prevented from being etched during the preparation process, which is conducive to improving the The quality of single crystal diamond heteroepitaxy to obtain large-area epitaxial films by heteroepitaxy.

Description of drawings

FIG. 1 is a schematic structural diagram of a graphene intermediate layer flexible substrate for heteroepitaxy according to an embodiment of the present disclosure.

FIG. 2 is a flow chart of a method for preparing a graphene intermediate flexible substrate for heteroepitaxy according to an embodiment of the present disclosure.

[Description of Symbols of Main Elements of the Embodiments of the Present Disclosure in the Drawings]

10-Support layer;

20-buffer layer;

21-Graphene buffer layer;

22-metal film buffer layer;

S1~S3-steps.

Detailed ways

The present disclosure provides a graphene intermediate layer flexible substrate for heteroepitaxy and a preparation method thereof. The graphene intermediate layer flexible substrate used for heteroepitaxy includes in order from bottom to top: a support layer and a A buffer layer, the buffer layer sequentially includes: at least one graphene buffer layer and at least one metal film buffer layer from bottom to top. The arrangement of the graphene buffer layer and the metal film buffer layer disclosed in the present disclosure reasonably utilizes the advantages of small lattice adaptation of graphene, and under the protection of the metal film buffer layer, the graphene can be prevented from being etched during the preparation process, which is conducive to improving the The quality of single crystal diamond heteroepitaxy to obtain large-area epitaxial films by heteroepitaxy.

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the specific embodiments and the accompanying drawings.

Certain embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, some but not all embodiments of which are shown. Indeed, various embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth in this number; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

In an exemplary embodiment of the present disclosure, a graphene interlayer flexible substrate for heteroepitaxy is provided. FIG. 1 is a schematic structural diagram of a graphene intermediate layer flexible substrate for heteroepitaxy according to an embodiment of the present disclosure. As shown in FIG. 1 , the graphene intermediate layer flexible substrate for heteroepitaxy of the present disclosure includes, from bottom to top, a support layer 10 and a buffer layer 20, and the buffer layer 20 includes, from bottom to top, in order : at least one graphene buffer layer 21 and at least one metal film buffer layer 22 .

Each component of the graphene intermediate layer flexible substrate for heteroepitaxy in this embodiment will be described in detail below.

The supporting layer 10 can be a single material of any one of silicon carbide, silicon, sapphire, quartz, glass and metal, or can be a composite material of any one of silicon carbide, silicon, sapphire, quartz, glass and metal .

The graphene buffer layer 21, the thickness of the graphene buffer layer 21 is 1-50 atomic layers.

The metal film buffer layer 22, the thickness of the metal film buffer layer 22 is 2-100 nm. The material of the metal film buffer layer 22 is one or more of Pt, Ir, and Cu.

In another exemplary embodiment of the present disclosure, a method for preparing a graphene intermediate layer flexible substrate for heteroepitaxy is also provided. FIG. 2 is a flow chart of a method for preparing a graphene intermediate flexible substrate for heteroepitaxy according to an embodiment of the present disclosure. As shown in FIG. 2, the present disclosure is used for the preparation method of the heteroepitaxy graphene intermediate layer flexible substrate, including:

Step S1, performing surface treatment on the support layer to remove organic and inorganic chemical pollutants on the surface of the support layer.

Step S2, placing the support layer after the surface treatment in step S1 in a reaction chamber, the gas atmosphere is one or more of argon and hydrogen, the temperature range is 1500-1700°C, and the pressure range in the reaction chamber is 1-700 Torr, the growth time is 5-120 min, and a graphene buffer layer is prepared on the upper surface of the support layer. The upper surface of the support layer will be further described. Here, the upper surface of the support layer may be a C-plane, a Si-plane, or any other suitable structure.

Step S3, using magnetron sputtering to prepare a metal film buffer layer on the graphene buffer layer prepared in step S2.

In a specific embodiment, a graphene buffer layer is formed on the 4H-SiC support layer, and then a Pt metal film buffer layer is plated on the graphene layer buffer layer. Specifically as follows:

In step S1, standard RCA cleaning is performed on the polished 4H-SiC support layer to remove organic and inorganic chemical pollutants on the surface of the 4H-SiC support layer sample.

In step S2, a graphene buffer layer is prepared on the C surface of the 4H-SiC support layer by a pyrolysis method. The surface-treated 4H-SiC support layer was placed in the reaction chamber, and the gas atmosphere was pure argon. Generally speaking, the optimal temperature range is 1500°C-1700°C, and the gas pressure in the reaction chamber is 1-700 Torr. In this embodiment, preferably, the growth temperature of the graphene buffer layer is 1650°C, and the gas pressure is 40 Torr. Under these conditions, a graphene buffer layer with a thickness of 2 atomic layers can be obtained by growing for 30 min. It should be understood by those skilled in the art that, if more layers of graphene buffer layers are required, the growth time can be extended or the growth temperature can be increased. Generally speaking, the thickness of the optimal graphene buffer layer is 1-50 atomic layers. , those skilled in the art should understand that the thickness of the graphene buffer layer is about 0.35-20 nm.

In step S3, magnetron sputtering is used to coat a Pt metal film buffer layer on the graphene buffer layer prepared in step S2, and the thickness of the metal film buffer layer is 2-100 nm. The thinner the thickness, the better. In this embodiment, the thickness of the metal film buffer layer is preferably 20 nm.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or the text of the description, the implementations that are not shown or described are in the form known to those of ordinary skill in the technical field, and are not described in detail. In addition, the above definitions of various elements and methods are not limited to various specific structures, shapes or manners mentioned in the embodiments, and those of ordinary skill in the art can simply modify or replace them.

Based on the above description, those skilled in the art should have a clear understanding of the graphene intermediate layer flexible substrate for heteroepitaxy and the preparation method thereof of the present disclosure.

In summary, the present disclosure provides a graphene interlayer flexible substrate for heteroepitaxy and a preparation method thereof. By using a buffer layer structure of a combination of a graphene buffer layer and a metal film buffer layer, the graphene lattice is rationally utilized. The advantage of small adaptation is that under the protection of the metal film buffer layer, graphene can be prevented from being etched during the preparation process, which is conducive to improving the quality of single crystal diamond heteroepitaxy to achieve large-area and high-quality diamond film heteroepitaxy. Epitaxial growth.

It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", etc., only refer to the directions of the drawings, not used to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are denoted by the same or similar reference numbers. Conventional structures or constructions will be omitted when it may lead to obscuring the understanding of the present disclosure.

Moreover, the shapes and sizes of the components in the figures do not reflect the actual size and proportion, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Unless known to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained from the teachings of the present disclosure. Specifically, all numbers used in the specification and claims to indicate compositional contents, reaction conditions, etc., should be understood as being modified by the word "about" in all cases. In general, the meaning expressed is meant to include a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±1% in some embodiments. Example ±0.5% variation.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Furthermore, unless the steps are specifically described or must occur sequentially, the order of the above steps is not limited to those listed above, and may be varied or rearranged according to the desired design. And the above embodiments can be mixed and matched with each other or with other embodiments based on the consideration of design and reliability, that is, the technical features in different embodiments can be freely combined to form more embodiments.

Similarly, it will be appreciated that in the above description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together into a single embodiment, figure, or its description. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the present disclosure.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included within the protection scope of the present disclosure.

Claims (8)

1. A graphene interlayer flexible substrate for heteroepitaxy, comprising in order from bottom to top: supporting layer and buffer layer, the buffer layer includes from bottom to top in order: at least one graphene buffer layer and at least one metal film buffer layer.

2. The graphene interlayer flexible substrate according to claim 1, wherein the graphene buffer layer has a thickness of 1 to 50 atomic layers.

3. The graphene interlayer flexible substrate according to claim 1, wherein the metal film buffer layer has a thickness of 2 to 100 nm.

4. The graphene interlayer flexible substrate according to claim 1, wherein the metal film buffer layer is made of one or more of Pt, Ir and Cu.

5. The graphene interlayer flexible substrate according to claim 1, wherein the material of the support layer is a simple substance material or a composite material of any more of silicon carbide, silicon, sapphire, quartz, glass and metal.

6. A method of preparing a graphene interlayer flexible substrate for heteroepitaxy as claimed in claims 1 to 5, comprising the steps of:

s1, carrying out surface treatment on the supporting layer to remove organic and inorganic chemical pollutants on the surface of the supporting layer;

s2, placing the support layer subjected to surface treatment in the step S1 in a reaction chamber, wherein the gas atmosphere is one or more of argon and hydrogen, the temperature range is 1500-1700 ℃, the gas pressure range in the reaction chamber is 1-700Torr, and a graphene buffer layer is prepared on the upper surface of the support layer;

and S3, preparing a metal film buffer layer on the graphene buffer layer prepared in the step S2 by utilizing magnetron sputtering.

7. The method for preparing a porous membrane according to claim 6, wherein the support layer is surface-treated by standard RCA cleaning in step S1.

8. The preparation method according to claim 6, wherein the growth time of the support layer in the reaction chamber in the step S2 is 5-120 min.

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