A method for preparing internal flow channel of diamond based on arc effect

Abstract

The application provides a diamond internal flow channel preparation method based on arc effect, and aims at solving the technical problem that the existing flow channel processing method is difficult to process the internal flow channel of diamond, or the processed internal flow channel cannot meet the micro-nanometer scale requirement of a chip. The diamond internal flow channel preparation method provided by the application comprises the following steps: first, a surface flow channel is processed on the surface of the diamond through a laser beam; then, the diamond is placed in a sealed container; a microwave generator is used to emit microwaves into the sealed container, so that the microwaves are focused on the surface flow channel, and the diameter of the focus point of the microwaves is greater than the width of the surface flow channel; the microwaves form two arcs at the two sharp ends of the surface flow channel respectively, and the two arcs intersect and overlap to form a mixed arc; after the surface flow channel is completely shielded by the mixed arc, C elements are deposited on the surface of the diamond layer by layer to form a finished diamond, and the preparation of the internal flow channel of the diamond is completed. The internal flow channel prepared by the application can meet the micro-nanometer scale requirement of a chip.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing a diamond flow channel, in particular to a method for preparing a diamond internal flow channel based on an electric arc effect. BACKGROUND

[0002] Diamond crystals have extremely high hardness, thermal conductivity and excellent chemical stability. Diamond can be divided into two categories: natural and synthetic. Natural single crystal diamond, also known as diamond, is extremely rare in nature and very expensive. It is mainly used for jewelry and has limited industrial applications. Synthetic diamond can be divided into single crystal and polycrystalline diamond. Single crystal diamond has higher purity and better quality than polycrystalline diamond, and does not have irregular grain boundaries. Therefore, it is widely used in mechanical manufacturing and semiconductor industries.

[0003] Diamond is considered the most ideal chip heat dissipation substrate material due to its excellent heat dissipation performance and has been applied in many fields. The internal flow channel of diamond is a new technical means for semiconductor chip heat dissipation substrate. The specific principle is that a flow channel is processed in the diamond, and cooling water is introduced into the processed internal flow channel. The boiling heat transfer mechanism can increase the material thermal conductivity by at least one time. At present, the methods for processing diamond flow channels include self-assembly, hydrothermal method, template method, chemical vapor deposition method, electrochemical etching method and laser method. However, the above methods cannot meet the processing requirements of diamond internal flow channels based on chip heat dissipation. Among them, the self-assembly method, the hydrothermal method and the electrochemical etching method can only process the surface flow channel of diamond and cannot process the internal flow channel. The template method and the chemical vapor deposition method can process the internal flow channel of diamond, but the processed internal flow channel has a size of more than one millimeter and cannot be used for micro-nano scale chips. The traditional laser processing is difficult to form an internal flow channel because the residue after laser processing is not easy to remove due to the stable chemical properties of diamond. Therefore, the processing difficulty of diamond internal flow channel is a major bottleneck restricting the application of diamond chip heat dissipation substrate. SUMMARY

[0004] The present application aims to solve the technical problem that the existing processing methods cannot process the internal flow channel of diamond or the processed internal flow channel of diamond cannot meet the requirements of micro-nano scale chips, and provides a method for preparing a diamond internal flow channel based on an electric arc effect.

[0005] In order to achieve the above-mentioned purpose, the technical solution provided by the present application is as follows:

[0006] A method for preparing a diamond internal flow channel based on an electric arc effect, characterized by comprising the following steps:

[0007] 1】focus a laser beam on the surface of the diamond, and process a surface flow channel on the surface of the diamond by the laser beam;

[0008] 2】place the diamond with the processed surface flow channel in a sealed container, and place a microwave generator outside the sealed container, and emit microwaves into the sealed container by the microwave generator; the sidewall of the sealed container is a microwave-penetrable material, and the sealed container is in a vacuum environment;

[0009] 3】adjust the focusing position and focusing spot size of the microwaves, so that the microwaves are focused on the surface flow channel of the diamond, and the focusing spot diameter of the microwaves is greater than the width of the surface flow channel; define the two edges of the surface flow channel in the width direction as sharp ends, then the microwaves generate arc effects at the two sharp ends respectively, and form two corresponding arcs; the arcs at the two sharp ends intersect and overlap, and form a mixed arc in the width direction above the surface flow channel;

[0010] 4】determine whether the surface flow channel is completely shielded by the mixed arc, if yes, execute step 5, if not, return to step 3】and adjust the focusing position of the microwaves until the surface flow channel is completely shielded by the mixed arc;

[0011] 5】deposit C element on the surface of the diamond shielded by the mixed arc in the sealed container layer by layer to form a finished diamond, and complete the preparation of the internal flow channel of the diamond.

[0012] Further, in step 2】the microwaves emitted by the microwave generator are electromagnetic waves with a frequency of 300MHz-300GHz, and the energy of the microwaves is greater than 10mW / cm 2 .

[0013] Further, in step 2】the vacuum degree of the sealed container is greater than 0.1MPa.

[0014] Further, step 5】is specifically:

[0015] introduce methane gas with a pressurized pressure greater than 0.1MPa into the sealed container, so that the methane gas is sprayed on the surface of the diamond shielded by the mixed arc, and a thermal environment is formed in the sealed container at the same time, the methane gas is dissociated under the thermal action of the thermal environment, and H element and C element are separated, the H element is volatilized, and the C element is deposited on the surface of the diamond layer by layer to form a finished diamond, and the preparation of the internal flow channel of the diamond is completed.

[0016] Further, in step 5】the purity of the methane gas is greater than 99%;

[0017] The thermal environment in the sealed container is formed by microwaves.

[0018] Further, in step 1, the laser beam is a Gaussian beam, the laser power is 0.1-1000W, and the laser frequency is 0-10MHz.

[0019] Further, in step 1, the focusing spot diameter of the laser beam is 0.1-100um.

[0020] Further, in step 1, the laser beam is a continuous laser or a pulsed laser.

[0021] Further, the connecting parts of the sealed container are all glued with elastic filling materials.

[0022] Further, in step 1, the processing shape of the surface flow channel is an arbitrary shape.

[0023] The beneficial effects of the present application compared with the prior art are as follows:

[0024] The diamond internal flow channel preparation method based on the electric arc effect provided by the present application first processes a surface flow channel on the surface of the diamond by laser, then forms electric arcs at the two sharp ends of the surface flow channel by microwaves, the two electric arcs intersect and overlap to form a mixed electric arc, and a shield is formed above the surface flow channel, so that the subsequently deposited C element cannot be deposited inside the surface flow channel, avoiding the problem that the residues of the internal flow channel directly processed by laser cannot be removed; at the same time, since the surface flow channel is processed by laser, the scale requirement of the chip micro-nanometer level can be met, the processing is simple, the practicability is strong, and the method can be widely applied to the diamond internal flow channel processing based on chip heat dissipation.

[0025] The diamond internal flow channel preparation method based on the electric arc effect provided by the present application processes a surface flow channel by laser, and then generates an internal flow channel by the surface flow channel, and this method can simply realize the processing of internal flow channels with different shapes and sizes through the laser processing method of the surface flow channel.

[0026] The diamond internal flow channel preparation method based on the electric arc effect provided by the present application has simple whole process, convenient operation, and is suitable for industrial application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a flow chart of the diamond internal flow channel preparation method based on the electric arc effect of the present application;

[0028] Figure 2 is a schematic diagram of step 1 of the diamond internal flow channel preparation method based on the electric arc effect of the present application;

[0029] Figure 3 is a schematic diagram of step 2 of the diamond internal flow channel preparation method based on the electric arc effect of the present application;

[0030] Figure 4 is a schematic diagram of step 3 of a diamond internal flow channel preparation method based on arc effect of the present application;

[0031] Figure 5 is a schematic diagram of C element deposition in step 5 of a diamond internal flow channel preparation method based on arc effect of the present application;

[0032] Figure 6 is a schematic diagram of forming finished diamond in step 5 of a diamond internal flow channel preparation method based on arc effect of the present application;

[0033] Specific reference signs are as follows:

[0034] 1-laser beam; 2-diamond; 3-surface flow channel; 4-sealed container; 5-microwave generator; 6-microwave; 7-arc; 8-C element; 9-finished diamond. DETAILED DESCRIPTION

[0035] In order to make the advantages and characteristics of the present application clearer, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0036] A diamond internal flow channel preparation method based on arc effect, as shown in Figure 1 , specifically includes the following steps:

[0037] 1】As shown in Figure 2 , a laser processing method is used to focus the laser beam 1 on the surface of the diamond 2, and a surface flow channel 3 is processed on the surface of the diamond 2 by the laser beam 1.

[0038] In this embodiment, the laser beam 1 is a Gaussian beam, the laser power is set to 0.1-1000W, and the laser frequency is set to 0-10MHz. The laser type of the laser beam 1 can be selected as continuous laser or pulsed laser. Specifically, according to the processing size and quality requirements of the surface flow channel 3, continuous laser is used to process flow channels with larger size and general quality, and pulsed laser is used to process flow channels with smaller size and higher quality. The focusing spot size of the laser beam 1 determines the width of the flow channel processed at a time, and the diameter of the focusing spot ranges from 0.1 to 100um. When a wider surface flow channel 3 needs to be processed on the surface of the diamond, multiple parallel laser beams 1 are used to achieve this.

[0039] The surface flow channel 3 processed on the surface of the diamond by the laser beam 1 can be a straight line, a broken line or any other arbitrary shape. Defining the length direction of the diamond as the x direction, the width direction as the y direction, and the height direction as the z direction, the laser beam 1 scans a specific trajectory in the xy plane under the control of the computer data and the driving of the platform using digital scanning galvanometer or other scanning methods, and achieves the set thickness in the z direction to achieve the required arbitrary flow channel shape.

[0040] 2】As Figure 3 shown, the diamond 2 which will be processed to form the surface flow channel 3 is placed in a sealed container 4, and a microwave generator 5 is placed outside the sealed container 4, and the microwave generator 5 emits microwaves 6 into the sealed container 4.

[0041] The side wall of the sealed container 4 is made of glass, plastic, porcelain or other materials which can be penetrated by microwaves, and the sealed container 4 is in a vacuum environment. The microwaves 6 penetrate the outer protection of the sealed container 4, and since the microwaves 6 do not generate heating or other effects on the sealed container 4, the energy density of the microwaves 6 does not decrease after penetrating the sealed container 4. In this embodiment, the vacuum degree of the sealed container 4 is greater than 0.1 MPa; specifically, a vacuum pump or other device can be used to generate a vacuum to ensure the vacuum environment in the sealed container 4. At the same time, the sealed container 4 is a fully enclosed sealed container, and the protection connection parts of the sealed container 4 are glued with elastic filling materials, which can ensure that the vacuum degree in the sealed container 4 does not change for more than 8 hours.

[0042] The microwave generator 5 is used to generate high-frequency microwaves 6, and the microwaves 6 are preferably electromagnetic waves with a frequency of 300 MHz-300 GHz, and the energy of the microwaves 6 is greater than 10 mW / cm 2 .

[0043] 3】As Figure 4 shown, the focusing position and focusing spot size of the microwaves 6 are adjusted so that the microwaves 6 are focused on the surface flow channel 3 of the diamond 2, and the diameter of the focusing spot of the microwaves 6 is greater than the width of the surface flow channel 3, that is, the focusing area of the microwaves 6 completely shields the area of the surface flow channel 3.

[0044] The two edges of the surface flow channel 3 in the width direction are defined as sharp ends, and at this time, the microwaves 6 generate arc effects at the two sharp ends of the surface flow channel 3, that is, the electron aggregation effect caused by the irradiation of electromagnetic waves to the sharp ends, also known as sharp end discharge effect, and then form two corresponding arcs 7. The formed arc 7 is an electronic mixture of electron collection and plasma, and the density is greater than 1e5 m -3 The arcs 7 at the two sharp ends of the surface flow channel 3 intersect and overlap, and form a relatively large mixed arc in the width direction above the surface flow channel, which is used to shield the surface flow channel 3 during subsequent C deposition.

[0045] The microwave 6 generated by the microwave generator 5 can directly act on the surface flow channel 3, or can act on the surface flow channel 3 through optical reflection, i.e. through the setting of focusing devices in the sealed container 4. Therefore, when the focusing position of the microwave 6 is adjusted, the position of the microwave generator 5 or the position of the focusing device can be adjusted. The size of the focusing point of the microwave 6 can be adjusted by adjusting the parameters of the microwave generator 5 or the focal length of the focusing device of the microwave 6.

[0046] 4】Determine whether the surface flow channel 3 is completely shielded by the mixed arc. If yes, step 5 is executed; if no, return to step 3】and adjust the focusing position of the microwave 6 so that the microwave 6 is focused on a position where the surface flow channel 3 is not shielded by the mixed arc, form a corresponding mixed arc, until the surface flow channel 3 is completely shielded by the mixed arc.

[0047] 5】Introduce methane gas with a pressurized pressure greater than 0.1 MPa into the sealed container 4, so that the methane gas is sprayed on the surface of the diamond 2 shielded by the mixed arc, and at the same time, continuously emit the microwave 6 into the sealed container 4 through the microwave generator 5, so that the methane gas is dissociated under the thermal action of the microwave 6, i.e. CH4 is decomposed into C element 8 and H element. As shown in Figure 5 , the H element is volatilized, and the C element 8 is heat-sinked. In the process of heat-sinking, since the surface flow channel 3 is shielded, the C element 8 will not be deposited into the inside of the surface flow channel 3, but will only combine with the surface C element of the diamond 2 to form a finished product diamond 9, as shown in Figure 6 , the preparation of the internal flow channel of the diamond is completed.

[0048] During the deposition process, the focusing point of the microwave 6 and the spraying position of the methane gas are moved layer by layer along the z direction to complete the layer-by-layer deposition of the C element 8. During the deposition, the C element 8 is longitudinally deposited along the z direction, and is transversely deposited along the x direction and the y direction, so that the C element 8 completely shields the entire surface of the diamond 2.

[0049] Preferably, the purity of the methane gas is greater than 99%, which can ensure the purity of the deposited diamond. In the present embodiment, the microwave 6 forms a thermal environment, so that the methane gas is dissociated under the thermal action of the microwave 6. In other embodiments of the present application, other existing methods can be used to form a thermal environment in the sealed container 4 to produce thermal action on the methane gas. At the same time, in the present embodiment, the method of thermal deposition of methane gas is used to deposit the C element 8 layer by layer on the surface of the diamond 2. In other embodiments of the present application, the C element 8 can also be deposited layer by layer by chemical deposition or other deposition methods.

[0050] The diamond 2 in the present application is a diamond before growth, is a lower half of a finished diamond 9, is a diamond material for laser processing a surface runner 3, and has a thickness of 0.01-10 mm. The diamond 2 can be a single crystal diamond or a polycrystal diamond. The finished diamond 9 is a diamond after growth, is a final product of the diamond 2, and has the same material as the diamond 2. The finished diamond 9 has an internal runner 3 generated therein, and has a thickness of 0.01-20 mm, which is greater than the thickness of the diamond 2.

[0051] The above description is only used to explain the technical solutions of the present application, and not intended to limit the same. Those skilled in the art can make modifications to the specific technical solutions described in the above embodiments, or make equivalent replacements to some of the technical features, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present application.

Claims

1. A method for preparing internal flow channels in diamond based on the electric arc effect, characterized in that, Includes the following steps:

1. Focus the laser beam (1) on the surface of the diamond (2) and process the surface flow channel (3) on the surface of the diamond (2) through the laser beam (1); 2】The diamond (2) with surface flow channels (3) is placed in a sealed container (4), and a microwave generator (5) is placed outside the sealed container (4). The microwave generator (5) emits microwaves (6) into the sealed container (4). The side wall of the sealed container (4) is made of microwave-permeable material, and the inside of the sealed container (4) is a vacuum environment. The microwaves (6) emitted by the microwave generator (5) are electromagnetic waves with a frequency of 300MHz-300GHz, and the energy of the microwaves (6) is greater than 10mW / cm. 2 The vacuum degree of the sealed container (4) is greater than 0.1 MPa; 3】Adjust the focusing position and focusing point size of the microwave (6) so that the microwave (6) is focused on the surface channel (3) of the diamond (2) and the focusing point diameter of the microwave (6) is greater than the width of the surface channel (3); define the two edges of the surface channel (3) in the width direction as the tip, then the microwave (6) generates an electric arc effect at the two tips respectively, forming two corresponding electric arcs (7); the electric arcs (7) located at the two tips cross and overlap, forming a mixed electric arc in the width direction above the surface channel; 4】Determine whether the surface flow channel (3) is completely shielded by the mixed arc. If yes, proceed to step 5. If no, return to step 3】and adjust the focusing position of the microwave (6) until the surface flow channel (3) is completely shielded by the mixed arc. 5】Pressing a methane gas with a pressure greater than 0.1 MPa into a sealed container (4) so ​​that the methane gas is sprayed onto the surface of the diamond (2) which is shielded from the mixed electric arc. At the same time, a thermal environment is formed in the sealed container (4). The methane gas dissociates under the thermal effect of the thermal environment, separating H and C elements. The H element volatilizes, and the C element is deposited layer by layer on the surface of the diamond (2) to form the finished diamond (9), thus completing the preparation of the internal flow channel of the diamond.

2. The method for preparing diamond internal flow channels based on the electric arc effect according to claim 1, characterized in that: In step 5, the purity of the methane gas is greater than 99%; The thermal environment inside the sealed container (4) is formed by microwaves (6).

3. The method for preparing diamond internal flow channels based on the electric arc effect according to claim 2, characterized in that: In step 1], the laser beam (1) is a Gaussian beam with a laser power of 0.1~1000W and a laser frequency of 0~10MHz.

4. The method for preparing diamond internal flow channels based on the electric arc effect according to claim 3, characterized in that: In step 1, the focused spot diameter of the laser beam (1) is 0.1~100um.

5. A method for preparing diamond internal flow channels based on the electric arc effect according to any one of claims 1-4, characterized in that: In step 1, the laser beam (1) is a continuous laser or a pulsed laser.

6. The method for preparing diamond internal flow channels based on the electric arc effect according to claim 5, characterized in that: The connecting parts of the sealed container (4) are all glued with elastic filler material.

7. The method for preparing diamond internal flow channels based on the electric arc effect according to claim 6, characterized in that: In step 1, the surface flow channel (3) is processed into any shape.

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