Method for growing 2-dimensional structure in chemical vapor deposition system

Abstract

The present invention relates to a method (100) for growing 2D structures on materials in the form of glass coverslips and flexible sheets that cannot withstand high temperatures in a chemical vapor deposition system without damaging them, and for preventing the loss of yield and durability during the transfer of 2D material from the metallic substrate used as a catalyst to the target substrate.

Description

[0001] METHOD FOR GROWING 2-DIMENSIONAL STRUCTURE IN CHEMICAL VAPOR DEPOSITION SYSTEM

[0002] Technical Field

[0003] The present invention relates to a method for growing 2D structures on materials in the form of glass coverslips and flexible sheets that cannot withstand high temperatures in a chemical vapor deposition system without damaging them, and for preventing the loss of yield and durability during the transfer of 2D material from the metallic substrate used as a catalyst to the target substrate.

[0004] Background of the Invention

[0005] The discovery of graphene has increased the interest in 2-dimensional materials and the scientific community has carried out many research and development activities for large surface and homogeneous production. Synthesis methods such as mechanical etching, chemical etching, chemical vapor deposition (CVD) are widely used. However, there is no method that enables 2D materials to be grown both in large areas and without the use of metal catalysts and to be easily used in different applications without the need for transfer. Although CVD is one of the most suitable techniques for the production of 2D materials in large areas, its inability to be grown homogeneously on the desired substrate leads to difficulties in 2D device applications. For example, factors such as the use of catalyst metals such as copper and nickel for graphene production; the requirement of molybdenum (as precursor) and copper (as catalyst) for MXene synthesis; the need to use substrates such as copper and silver for borophene synthesis; as well as the losses incurred during the material transfer process and the difficulty of this process should be taken into account. Deposition is a common phenomenon in nature in which a substance in the gas phase crystallizes and turns into a solid by cooling rapidly. The main factors affecting deposition are high humidity, open air, temperature difference and surface properties. The fact that the deposition process is inherently associated with 2D growth sheds light on the ability to grow 2D crystal structures on the desired surface in CVD. There is a need for a new method to eliminate the transfer step, which is an important obstacle to increasing the use of 2D materials in a wide range of possible industrial applications, in other words, to increase both the production yield and performance of the 2D material-based devices obtained by overcoming problems such as loss of yield and durability during the transfer from the metallic substrate used as a catalyst to the target substrate.

[0006] The United States patent document no. US2022399201, an application included in the state of the art, discloses a method of producing a two-dimensional material. The method is based on the production of graphene or other two-dimensional materials such as graphene. Besides graphene, silicon, phosphorene, borophene, germanene and graphene allotropes of silicon, phosphorus, boron, germanium and carbon are among the two-dimensional materials. The method comprises heating the substrate held within a reaction chamber to a temperature within the decomposition range of a precursor, which allows the formation of two- dimensional crystalline material of a type released from a precursor. The decomposed precursor allows for the creation of a steep temperature gradient (preferably >1000°C per meter) that extends away from the substrate surface towards an inlet for the precursor and introduces the precursor material through the relatively cold inlet and across the temperature gradient towards the substrate surface. The steep temperature gradient ensures that the precursor remains substantially cool until it is proximate the substrate surface thus minimizing decomposition or other reaction of the precursor before it is proximate the substrate surface. Glass, plastic and fiber-reinforced polymers are used as substrates. Summary of the Invention

[0007] An object of the present invention is to realize a method for growing 2D structures on materials in the form of glass coverslips and flexible sheets that cannot withstand high temperatures in a chemical vapor deposition system without damaging them.

[0008] Another object of the present invention is to realize a method for eliminating the transfer step, which is an important obstacle to increasing the use of 2D materials in a wide range of industrial applications, that is, overcoming problems such as loss of yield and durability during the transfer from the metallic substrate used as a catalyst to the target substrate, thus increasing both the production yield and performance of the obtained 2D material-based devices.

[0009] Detailed Description of the Invention

[0010] “Method for Growing 2-Dimensional Structure in Chemical Vapor Deposition System” realized to fulfil the objectives of the present invention is shown in the figures attached, in which:

[0011] Figure 1 is a flowchart of the inventive method.

[0012] Figure 2 is a general view of the chemical vapor deposition (CVD) system in which the inventive method is carried out.

[0013] Figure 3 is a graph of X-Ray diffraction (XRD) spectroscopy of borophene structures produced by the inventive method.

[0014] 100. Method

[0015] 101. forming precursors by sublimation of the precursor powders intended to be deposited on the substrate in a vacuum environment in the first thermal zone (C) of a CVD furnace (A) with two different temperature zones (C, D) thermally insulated with a thermal insulator (B)

[0016] 102. producing homogeneous 2D material on a large surface directly on the target substrate by crystallization of precursors on the desired substrate after undergoing super-condensation in the second thermal zone (D)

[0017] A. CVD furnace

[0018] B . Thermal insulator

[0019] C. First thermal zone

[0020] D. Second thermal zone

[0021] The inventive method (100) for growing 2D structures on substrates that cannot withstand high temperatures in a chemical vapor deposition system without damaging them, and for preventing the loss of yield and durability during the transfer of 2D material from the metallic substrate used as a catalyst to the target substrate comprises the steps of: forming precursors by sublimation of the precursor powders intended to be deposited on the substrate in a vacuum environment in the first thermal zone (C) of a CVD furnace (A) with two different temperature zones (C, D) thermally insulated with a thermal insulator (B) (101); and producing homogeneous 2D material on a large surface directly on the target substrate by crystallization of precursors on the desired substrate after undergoing super-condensation in the second thermal zone (D) (102).

[0022] In the inventive method (100), substrates that cannot withstand high temperatures in the form of glass, plastic, fiber fabric or flexible sheet are placed in a CVD furnace (A) in a vacuum environment (101). Precursor powders of 2D materials such as graphene, Sb2Se3 veya M02C (MXene) that are intended to be produced on the substrate are taken into the first thermal zone (C) and here they form precursors that are ready for chemical reaction by passing directly from solid to gas by means of sublimation in the lower temperature range compared to the sublimation temperatures at atmospheric pressure (101). Then, the precursors in the vapor phase are enabled to be crystallized by undergoing super-condensation by applying a high temperature difference of at least 200 °C to the substrate and precursor in the second thermal zone (D) against the temperature applied in the first thermal zone (C) (102). The temperature difference between the first thermal zone (C) and the second thermal zone (D) is provided by the heat insulator (B) and as a result, a 2D material is obtained on the target substrate by forming crystallization similar to deposition with supersaturation (102).

[0023] With the inventive method (100), 2D homogeneous growth is shown in the second thermal zone (D), which is at least 200 °C lower than the reaction temperature in the first thermal zone (C) in the CVD system. X-Ray diffraction (XRD) spectroscopy of the borophene structures produced as an example is shown in Figure 3. It is possible to produce different 2D such as MXene, Sb2Se3 by the same method. The 2D crystal growth method (100) demonstrated by this invention will enable various applications in many fields such as materials science, semiconductor industry and nanotechnology.

[0024] Industrial Application of the Invention

[0025] In many studies on the production of 2D materials by CVD, the substrate reaction temperature is increased to high temperatures for sufficient surface activation. For example, for graphene or M02C (MXene) CVD growth, it is required to raise the temperature up to 1100 °C and use a metallic substrate such as copper. By means of the inventive method (100), it is enabled to realize a precise and controlled crystal growth on a large surface directly on the target substrate without the need to raise the substrate on which 2D material is to be produced to high temperatures or without the need to produce 2D material on the metallic substrate and then transfer the material to the target substrate (which results in yield and performance losses) since 2D material cannot be produced on substrates that cannot withstand high temperatures. In this way, homogeneous 2D crystal formation over a large surface is made possible.

[0026] Within these basic concepts; it is possible to develop various embodiments of the inventive “Method (100) for Growing 2-Dimensional Structure in Chemical

[0027] Vapor Deposition System”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

Claims

CLAIMS1. A method (100) for growing 2D structures on substrates that cannot withstand high temperatures in a chemical vapor deposition system without damaging them, and for preventing the loss of yield and durability during the transfer of 2D material from the metallic substrate used as a catalyst to the target substrate characterized by the steps of forming precursors by sublimation of the precursor powders intended to be deposited on the substrate in a vacuum environment in the first thermal zone (C) of a CVD furnace (A) with two different temperature zones (C, D) thermally insulated with a thermal insulator (B) (101); and producing homogeneous 2D material on a large surface directly on the target substrate by crystallization of precursors on the desired substrate after undergoing super-condensation in the second thermal zone (D) (102).

2. A method (100) according to Claim 1; characterized in that substrates that cannot withstand high temperatures in the form of glass, plastic, fiber fabric or flexible sheet are placed in a CVD furnace (A) in a vacuum environment (101).

3. A method (100) according to Claim 1 or 2; characterized in that precursor powders of 2D materials such as graphene, Sb2Se3 veya M02C (MXene) that are intended to be produced on the substrate are taken into the first thermal zone (C) and here they form precursors that are ready for chemical reaction by passing directly from solid to gas by means of sublimation in the lower temperature range compared to the sublimation temperatures at atmospheric pressure (101).

4. A method (100) according to any one of the preceding claims; characterized in that the precursors in the vapor phase are enabled to be crystallized by undergoing super-condensation by applying a high temperaturedifference of at least 200 °C to the substrate and precursor in the second thermal zone (D) against the temperature applied in the first thermal zone (C) (102).

5. A method (100) according to any one of the preceding claims; characterized in that the temperature difference between the first thermal zone (C) and the second thermal zone (D) is provided by the heat insulator (B) and as a result, a 2D material is obtained on the target substrate by forming crystallization similar to deposition with supersaturation (102).

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