Diamond substrate, diamond support and preparation method thereof

Abstract

The present application relates to a diamond substrate, a diamond load and a preparation method thereof. The preparation method of the diamond substrate comprises: providing a diamond sheet having a first surface and a second surface opposite to each other; using a laser cutting method to open a through groove on the diamond sheet to obtain a grooved substrate, wherein a first at least partial area of ​​the surface of the grooved substrate is covered with carbon attachments; placing the grooved substrate in a hydrogen plasma device to expose a second at least partial area of ​​the grooved substrate to hydrogen plasma gas, wherein the second at least partial area completely overlaps or partially overlaps with the first at least partial area; providing hydrogen plasma gas to the grooved substrate to cause the hydrogen plasma gas to etch the second at least partial area to remove the carbon attachments in the second at least partial area to obtain a diamond substrate; the present application has a simple process, is efficient and quick, and can effectively improve the adhesion of the film layer on the side of the diamond through groove and improve the stability of the back-end product.

Description

Technical Field

[0001] The present application relates to the technical field of diamond-based thin film circuits, and in particular to a diamond substrate, a diamond load and a preparation method thereof. Background Art

[0002] Diamond has become the preferred material for manufacturing high-performance, high-frequency RF devices due to its low dielectric constant (3.5), high thermal conductivity (5 times that of copper, 8 times that of aluminum, and 10 times that of aluminum nitride), high temperature resistance and high breakdown electric field strength. It has shown broad application potential in high-tech fields such as microwave communications, 5G base stations, and radar systems.

[0003] The load is a passive component whose main function is to absorb excess power in RF or microwave systems and effectively alleviate the damage of reflected waves to equipment. The core of its reliability lies in its ability to withstand power. Diamond loads, thanks to the above unique advantages, show higher power carrying capacity and frequency response than power loads made of traditional AlN and BeO substrate materials under the same test environment.

[0004] The diamond load includes a front metal layer, a front resistor layer, a back metal layer, and a side metal layer. The key role of the side metal layer is to ensure good conduction between the back and front metal layers and achieve stable grounding. To form the side metal layer, it is necessary to first open a groove on the diamond substrate to expose the side, and then perform sputtering coating. However, the extremely high hardness of diamond makes the traditional grinding wheel cutting method unfeasible, and it can only rely on laser cutting. However, the laser cutting process will induce the transformation of SP3 phase diamond to SP2 phase graphite, and the generated carbon attachments such as carbon attachments will adhere to the laser cutting area. It has extremely strong hygroscopicity and adhesion and is difficult to remove. The lack of necessary adhesion between the carbon attachments and the sputtered metal layer, coupled with the release of water vapor at high temperature, causes bubbles and film peeling to easily appear at the diamond slot after sputtering coating under thermal stress testing, which seriously weakens the reliability and durability of the diamond load. Summary of the invention

[0005] The main purpose of the present application is to provide a diamond substrate, a diamond load and a preparation method thereof, which are used to solve the problem that carbon attachments on the diamond substrate are difficult to clean during the traditional diamond substrate manufacturing process.

[0006] To achieve the above object, the first aspect of the present application provides a method for preparing a diamond substrate, comprising the following steps:

[0007] providing a diamond sheet having opposing first and second faces;

[0008] A through groove of a predefined shape is formed on the diamond sheet by a laser cutting method, wherein the through groove penetrates the diamond sheet from the first surface to the second surface, so as to obtain a grooved substrate; wherein the surface of the grooved substrate includes the first surface, the second surface and the side wall of the through groove, and a first at least partial area of ​​the surface of the grooved substrate is covered with carbon attachments;

[0009] Placing the slotted substrate in a hydrogen plasma device, exposing a second at least partial region of the slotted substrate to hydrogen plasma gas, wherein the second at least partial region completely overlaps or partially overlaps with the first at least partial region;

[0010] A hydrogen plasma gas is provided to the grooved substrate, so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region, thereby obtaining the diamond substrate.

[0011] Furthermore, the step of placing the grooved substrate into a hydrogen plasma device comprises:

[0012] The second surface of the grooved substrate is placed on a carrier, and the carrier is arranged in the hydrogen plasma equipment.

[0013] Further, a plurality of convex ribs are arranged at intervals on the upper surface of the carrier platform, the second surface of the slotted substrate is in direct contact with the upper surface of the convex ribs, and the through groove of the slotted substrate intersects with the convex ribs; or,

[0014] The upper surface of the carrier platform is provided with a plurality of grooves distributed at intervals, the second surface of the grooved substrate is in direct contact with the upper surface of the carrier platform, and the through grooves of the grooved substrate intersect with the grooves.

[0015] Furthermore, after the step of placing the second surface of the grooved substrate on a carrier, and the carrier is arranged in the hydrogen plasma device, the method further comprises:

[0016] A cover plate is arranged on the first surface of the slotted substrate, and the cover plate is provided with hollow parts corresponding to the through slots one by one. The cover plate is adjusted so that each hollow part corresponds to the corresponding through slot one by one, so that the side wall of the through slot is exposed to the hydrogen plasma gas.

[0017] Furthermore, the through groove is within the projection range of the hollow portion on the first surface, and the distance between the edge of the hollow portion and the edge of the through groove is no more than 1 mm.

[0018] Further, the step of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain the diamond substrate comprises:

[0019] Controlling the hydrogen plasma equipment to heat up to an etching temperature within 30 to 60 minutes, wherein the etching temperature ranges from 800 to 850° C.;

[0020] Maintaining a preset etching time at the etching temperature so that the hydrogen plasma gas etches the second at least partial region, the etching time being greater than or equal to 20 minutes;

[0021] After etching is completed, the hydrogen plasma equipment is controlled to cool down to a predefined temperature within 30 to 60 minutes, and then naturally cools down to room temperature.

[0022] Furthermore, the etching time is positively correlated with the thickness of the diamond sheet.

[0023] Furthermore, before the step of placing the slotted substrate into a hydrogen plasma device to expose the second at least partial region of the slotted substrate to hydrogen plasma gas, wherein the second at least partial region completely overlaps or partially overlaps with the first at least partial region, the step includes:

[0024] performing a first cleaning on the slotted substrate to remove powder particles;

[0025] Cleaning the grooved substrate for a second time to remove organic oil stains;

[0026] performing a third cleaning on the grooved substrate to dehydrate;

[0027] The dehydrated grooved substrate is blown dry by inert gas.

[0028] Further, the step of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain the diamond substrate comprises:

[0029] Providing hydrogen plasma gas to the grooved substrate, so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain a decarbonized substrate;

[0030] performing a first cleaning on the decarbonized substrate to remove powder particles;

[0031] Performing a second cleaning on the carbon removal substrate to remove organic oil stains;

[0032] performing a third cleaning on the decarbonized substrate to dehydrate;

[0033] Blowing the dehydrated carbon-removed substrate dry with inert gas;

[0034] The decarbonized substrate after drying is placed in an oven for drying to obtain the diamond substrate.

[0035] Furthermore, the predefined shape of the through groove includes that the projection of a single through groove on the first surface or the second surface is a closed pattern, the closed pattern includes a middle portion and end portions arranged at both ends of the middle portion, the middle portion is rectangular, and the end portions are arc-shaped.

[0036] A second aspect of the present application provides a diamond substrate prepared by the above-mentioned method for preparing a diamond substrate.

[0037] The third aspect of the present application provides a method for preparing a diamond support, using the above-mentioned diamond substrate to prepare the diamond support, comprising the following steps:

[0038] The second surface of the diamond substrate faces upwards, and a first film layer is sputtered onto the second surface, wherein the first film layer includes a metal film layer, as a first substrate;

[0039] Place the first surface of the first substrate upward, and sputter a second film layer onto the first surface, wherein the second film layer includes a resistance film layer and a metal film layer, to serve as a second substrate;

[0040] Electroplating the first film layer and the second film layer to thicken the metal film layer to serve as a third substrate;

[0041] Performing photolithography and etching on the third substrate to pattern the resistance film layer to form a fourth substrate;

[0042] The resistance film layer of the fourth substrate is subjected to thermal oxidation resistance adjustment, and thermal testing is performed at a preset temperature for several minutes to tens of minutes to obtain a fifth substrate;

[0043] The fifth substrate is laser scribing and cutting to obtain the diamond loading.

[0044] A fourth aspect of the present application provides a diamond support, which is prepared using the above-mentioned diamond support preparation method.

[0045] The diamond substrate, diamond load and preparation method thereof provided in the present application are to etch the second at least partial region including the side wall of the through groove by hydrogen plasma gas, so as to remove the carbon attachments attached to the second at least partial region. The process is simple, efficient and fast, and can effectively improve the adhesion of the film layer on the side of the diamond through groove and enhance the stability of the back-end product (such as the diamond load). BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flow chart of a method for preparing a diamond substrate provided in one embodiment of the present application;

[0047] Figure 2 A schematic diagram of the shape of a through groove of a diamond substrate provided in one embodiment of the present application;

[0048] Figure 3 A cross-sectional schematic diagram of a slotted substrate provided in an embodiment of the present application being placed on a carrier;

[0049] Figure 4 A schematic diagram of a top view of a cover plate provided in an embodiment of the present application placed on a slotted substrate;

[0050] Figure 5 A flow chart of a method for preparing a diamond support provided in one embodiment of the present application;

[0051] Figure 6 A schematic diagram of the cross-sectional structure of a diamond load provided in one embodiment of the present application.

[0052] Figure 7 The image comparison of the area near the through groove of the diamond substrate before and after etching in Example 1 of the present application, wherein (a) is before etching and (b) is after etching;

[0053] Figure 8 The image comparison of the diamond loading of Example 1 and Comparative Example 1 of the present application after thermal testing, wherein (a) is a plan view of the diamond loading of Comparative Example 1, (b) is a partial enlarged view of the diamond loading of Comparative Example 1, (c) is a plan view of the diamond loading of Example 1, and (d) is a partial enlarged view of the diamond loading of Example 1.

[0054] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0056] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0057] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0058] Reference Figure 1 The present application discloses a method for preparing a diamond substrate, comprising the following steps:

[0059] S1: providing a diamond sheet having a first surface and a second surface opposite to each other;

[0060] S2: using a laser cutting method to open a through groove of a predefined shape on the diamond sheet, wherein the through groove penetrates the diamond sheet from the first surface to the second surface, to obtain a grooved substrate; wherein the surface of the grooved substrate includes the first surface, the second surface and the sidewall of the through groove, and the first at least part of the surface of the grooved substrate is covered with carbon attachments;

[0061] S3: placing the slotted substrate into a hydrogen plasma device, exposing the second at least partial region of the slotted substrate to the hydrogen plasma gas, wherein the second at least partial region completely overlaps or partially overlaps with the first at least partial region;

[0062] S4: providing hydrogen plasma gas to the grooved substrate, so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region, thereby obtaining a diamond substrate.

[0063] In the present embodiment, in the above step S1, the above diamond sheet is prepared by CVD (chemical vapor deposition), and the thickness of the diamond sheet can be selected according to the needs of the specific use scenario. Taking the use of a diamond substrate to make a diamond load as an example, the thickness of the diamond sheet can be selected to be 0.2-0.5 mm, etc., and conventional ones are 0.254 mm or 0.381 mm, etc. It can be understood that the first side of the diamond sheet corresponds to the first side of the slotted substrate and also corresponds to the first side of the diamond substrate, and the second side of the diamond sheet corresponds to the second side of the slotted substrate and also corresponds to the second side of the diamond substrate. As well as other substrates or loads named for the convenience of description in the specification of this application, the description involving the first side or the second side corresponds to the first side or the second side of the diamond sheet (substrate) respectively.

[0064] In the above step S2, refer to Figure 2 The shape of the through groove can be adjusted according to the needs of the specific use scenario. For example, it is a straight groove with a width of 0.2-0.25 mm. If the through groove is too wide, it will affect the coating area of ​​the diamond substrate and reduce its utilization rate. If the through groove is too narrow, it will be difficult to laser cut, and it will not be easy to deposit the metal film layer on the side during sputtering, resulting in poor contact between the first surface and the second surface. Therefore, the width of the through groove is limited to 0.2-0.25 mm, which is convenient for laser cutting and conducive to the deposition of the metal film layer on the side wall of the through groove, and can also improve the utilization rate of the diamond substrate and save the manufacturing cost of the subsequent diamond load. There can be multiple through grooves, and the specific number and the spacing width between adjacent through grooves are determined according to different product sizes. The first surface of the above-mentioned slotted substrate is the surface used for depositing the resistance film layer and the metal film layer when preparing the diamond-loaded products later; the second surface of the above-mentioned slotted substrate is the surface used for depositing the metal layer when preparing the diamond-loaded products later; since the resistance film layer is to be deposited on the first surface, the requirements for the smoothness and cleanliness of the first surface are much higher than those of the second surface; for the slotted substrate after laser slotting, it is easy to have residual carbon attachments at the slotting location, and the above-mentioned first at least partial area is the area covering the carbon attachments, and the first at least partial area includes the side wall of the through-slot, the area close to the through-slot in the first surface, and the area close to the through-slot in the second surface.

[0065] In some embodiments, the horizontal distance between the two ends of the through groove and the edge of the diamond substrate is greater than or equal to 3.5 mm. Because the groove is too close to the edge, it is easy to cause cracks in the diamond substrate. By making the horizontal distance between the two ends of the through groove and the edge of the diamond substrate greater than or equal to 3.5 mm, such as 3.5 mm or 4 mm or 4.5 mm, during or after laser cutting, cracks can be effectively prevented from occurring at the edge of the diamond substrate. Among them, laser cutting uses a laser cutting machine, such as an ultraviolet nanosecond laser cutting machine, an infrared laser cutting machine, etc.

[0066] In some embodiments, as an optional step after step S2, after laser cutting the diamond sheet to obtain the slotted substrate, the slotted substrate can be wiped back and forth with a dust-free cloth dipped in alcohol for more than 2 times, and then placed in an alcohol tank for ultrasonic treatment for more than 10 minutes, and then taken out after being blown dry with nitrogen before entering step S3. In this way, part of the carbon attachment formed on the substrate during the laser cutting process can be initially scrubbed off, thereby improving the efficiency of subsequent carbon removal.

[0067] In the above step S3, the hydrogen plasma device is a device for generating hydrogen plasma gas. In the hydrogen plasma device, hydrogen molecules are decomposed into positively charged hydrogen ions, negatively charged electrons and neutral hydrogen atoms by the action of electric field, magnetic field or microwave energy to form hydrogen plasma gas.

[0068] In some specific embodiments, the hydrogen plasma equipment is a MPCVD (Microwave Plasma Chemical Vapor Deposition) equipment.

[0069] In some specific embodiments, the second at least partial region includes at least a side wall of the through groove.

[0070] In some embodiments, the second at least partial region overlaps with the first at least partial region;

[0071] In some specific embodiments, the second at least partial area is within the range of the first at least partial area and is smaller than the first at least partial area;

[0072] In some further specific embodiments, the second at least partial region partially overlaps with the first at least partial region.

[0073] In the above step S4, the second at least partial area of ​​the slotted substrate is directly exposed to the atmosphere of hydrogen plasma gas, and the high-energy particles in the hydrogen plasma gas can interact with the surface of the second at least partial area of ​​the slotted substrate. Since the bonding between carbon atoms in the diamond structure is extremely strong, and the carbon atoms in non-diamond phases (i.e., carbon attachments) such as graphite amorphous carbon belong to van der Waals molecular forces, which are weakly bonded, they are more easily etched away by hydrogen atoms. The etching rate of hydrogen atoms on non-diamond phases is more than 1000 times that of etching diamonds, so that non-diamond phases such as carbon attachments can be efficiently removed in a short time, but the diamond has almost no effect or little effect. This method not only has a good effect on the removal of adsorbents such as carbon attachments, high efficiency and high speed, but can completely avoid the use of high-risk chemicals, thereby improving the metal adhesion of the through-groove sidewalls in the back-end product.

[0074] In some embodiments, the carbon deposits in the second at least partial region are removed, and the carbon deposits on the diamond sheet are completely removed.

[0075] In other embodiments, carbon attachments in the second at least partial region are removed, but carbon attachments in the first at least partial region and not in the second at least partial region are not directly exposed to the hydrogen plasma gas and are therefore not removed. These carbon attachments that have not been removed are further removed by other methods in the prior art such as wiping, brushing, and polishing.

[0076] For different diamond sheets, by controlling the overlap between the second at least partial area and the first at least partial area, a suitable decarbonization method can be flexibly selected. For example, the entire slotted substrate can be decarbonized by hydrogen plasma gas, or the carbon attachments in different areas of the slotted substrate can be divided into different areas, and different decarbonization methods can be used for different areas, thereby ensuring that the carbon attachments on the obtained diamond substrate are completely removed, while ensuring that the surface of the diamond substrate has sufficient smoothness to meet the demand for precision raw materials used as back-end products such as diamond loads.

[0077] In the embodiments of the present application, for the slotted substrate after laser slotting, it is easy to have residual carbon attachments at the slotting. For the carbon attachments remaining on the first surface and / or the second surface of the slotted substrate, the prior art discloses a variety of removal methods, such as whole-surface grinding, surface wiping, etc. However, it has not been found in the prior art that a plurality of residual carbon attachments will actually be formed on the inner side wall of the through groove of the slotted substrate during the processing, and the carbon attachments in the through groove are difficult to remove by the existing methods. In this embodiment, the carbon attachments attached to the second at least partial area including the side wall of the through groove are removed by etching with hydrogen plasma gas. The process is simple, efficient and fast, and can effectively improve the adhesion of the film layer on the side of the diamond through groove, and improve the stability of the back-end product (such as diamond load).

[0078] In a specific embodiment, step S3 of placing the grooved substrate into a hydrogen plasma device includes:

[0079] S301: placing the second surface of the grooved substrate on a carrier, wherein the carrier is disposed in a hydrogen plasma device.

[0080] In this embodiment, the supporting platform is made of molybdenum material and is used to place the slotted substrate.

[0081] In some optional embodiments, the surface where the carrier table and the second surface of the slotted substrate are bonded is a plane. After the second surface of the slotted substrate is placed on the carrier table, the second surface is bonded to the upper surface of the carrier table, and the second at least partial area is the first surface of the slotted substrate and the side wall of the through-slot. After executing step S4, the carbon attachments on the side wall of the through-slot and the area near the through-slot in the first surface are removed. Optionally, the slotted substrate is turned over, the first surface is placed on the carrier table, and step S4 is executed again to facilitate etching of the carbon attachments at the junction edge between the side wall of the through-slot and the second surface, and the area near the through-slot in the second surface. Optionally, the etching may no longer be turned over, but other methods in the prior art such as wiping, brushing, and polishing may be used to remove the carbon attachments in the area near the through-slot in the second surface.

[0082] In a specific embodiment, referring to Figure 3, a plurality of convex ribs 201 are arranged on the upper surface of the carrier 20 at intervals, the second surface of the slotted substrate 10 is in direct contact with the upper surface of the convex ribs 201, and the through slot 1 of the slotted substrate 10 intersects with the convex ribs 201. The convex ribs 201 are not parallel to the through slot 1, and the convex ribs 201 and the through slot 1 are at a certain angle, for example, perpendicular to each other, so that there is a gap 202 between the second surface of the slotted substrate 10 and the upper surface of the carrier 20, so that the hydrogen plasma gas can pass through the gap 202 to the second surface of the slotted substrate 10, then the second at least partial area is the first surface of the slotted substrate 10, the second surface of the slotted substrate 10 and the side wall of the through slot 1, and the hydrogen plasma gas simultaneously etches and removes the carbon attachments on the first surface, the second surface and the side wall of the through slot. The height of the convex ribs 201 can be 0.5-1mm, and the width of the convex ribs 201 can be 0.5-1mm. It is understandable that the area of ​​the second surface of the slotted substrate 10 that is in direct contact with the rib 201 cannot be exposed to the hydrogen plasma gas. However, since the rib 201 is very small in width and is intersecting with the through groove 1, the area of ​​the second surface actually blocked is very small and can be almost ignored.

[0083] In another specific embodiment, a plurality of grooves are arranged at intervals on the upper surface of the carrier, the second surface of the slotted substrate is in direct contact with the upper surface of the carrier, and the through groove of the slotted substrate intersects with the groove. The groove is not parallel to the through groove, and the groove and the through groove are at a certain angle, for example, perpendicular to each other, so that the second surface of the slotted substrate is not completely in contact with the upper surface of the carrier, but has a partial gap (i.e., the groove), so that the hydrogen plasma gas can pass through the gap to the second surface of the slotted substrate, then the second at least part of the area is the first surface of the slotted substrate, the second surface of the slotted substrate and the side wall of the through groove, and the hydrogen plasma gas simultaneously etches and removes the carbon attachments on the first surface, the second surface and the side wall of the through groove. The height of the groove can be 0.5-1mm, the width of the groove can be 0.5-1mm, and the spacing width between adjacent grooves is 0.5-1mm. It can be understood that the area where the second surface of the slotted substrate is in direct contact with the second surface of the slotted substrate cannot be exposed to the hydrogen plasma gas, but because the spacing width between adjacent grooves is small and intersecting with the through groove, the area of ​​the second surface actually blocked is very small and can be almost ignored.

[0084] In a specific embodiment, the second surface of the grooved substrate is placed on a carrier, and after step S301 of setting the carrier in a hydrogen plasma device, the following steps are included:

[0085] S302: a cover plate is disposed on the first surface of the slotted substrate, wherein the cover plate is provided with hollow portions corresponding to the through slots one by one, and the cover plate is adjusted so that each hollow portion corresponds to the corresponding through slot one by one, so that the sidewalls of the through slots are exposed to the hydrogen plasma gas.

[0086] In this embodiment, the above-mentioned cover plate can be made of molybdenum material. Specifically, a hollow portion is opened correspondingly according to the shape and distribution of the through grooves on the diamond sheet. The present application does not specifically limit the thickness of the cover plate, as long as the strength can meet the etching conditions of each embodiment of the present application. The hollow portion exposes the through groove, so that the side wall of the through groove is exposed to the hydrogen plasma gas, and in the subsequent etching process, the carbon attachments on the side wall of the through groove can be removed. The area covered by the cover plate on the first side is not directly exposed to the hydrogen plasma gas. When adjusting the placement angle of the cover plate, it can be achieved by manual adjustment, or by pre-set positioning points or any other feasible method.

[0087] In this embodiment, the second at least partial area does not include the area where the first surface of the slotted substrate contacts the cover plate. Since the diamond substrate needs to deposit a resistive film layer on the first surface when preparing products such as diamond loads, the smoothness of the first surface of the diamond substrate is very high. In some cases, such as when the amount of carbon attachments is small, the thickness of the diamond sheet is thin, and the shape of the through groove is simple and regular, the etching time of the hydrogen plasma gas can be controlled within a short time range to minimize the etching of the diamond phase on the first surface of the slotted substrate, thereby reducing the impact on the smoothness of the first surface of the slotted substrate. In other cases, such as when the thickness of the diamond sheet is thick and the amount of carbon attachments is large, the etching time needs to be increased, and the hydrogen plasma gas will also have a certain impact on the smoothness of the first surface of the slotted substrate. Therefore, in this embodiment, the first surface of the slotted substrate is shielded by the cover plate, thereby protecting the first surface for subsequent deposition of the resistive film layer; and by setting a hollow portion and setting a longer etching time that matches the thickness of the diamond sheet, the carbon attachments on the side wall of the through groove are completely removed by the hydrogen plasma gas. After the carbon deposits on the sidewalls of the through grooves are removed by step S4, a small amount of carbon deposits on the first surface can be removed by wiping, brushing, polishing, etc. in the prior art; or the cover plate can be removed again, and a shorter etching time is set, and step S4 is performed again to remove a small amount of carbon deposits on the first surface. The shorter etching time is in the range of 20 to 30 minutes, and the longer etching time is in the range of more than 30 minutes.

[0088] In some specific implementations of this embodiment, if the slotted substrate is placed on a flat carrier, the second at least partial area is the area where the first surface of the slotted substrate is not in contact with the cover plate, and the side wall of the through groove. If the area of ​​the hollow portion is completely consistent with the area of ​​the through groove, or the projection area of ​​the hollow portion on the first surface is smaller than the area of ​​the through groove, the second at least partial area is the side wall of the through groove. The unremoved carbon attachments on the first and second surfaces can be removed by wiping, brushing, polishing, etc. in the aforementioned prior art; or by performing step S4 again with a shorter etching time to remove a small amount of carbon attachments on the surface.

[0089] In some other specific implementations of this embodiment, if the slotted substrate is placed on a carrier with grooves or ribs, the second at least partial area is the second surface of the slotted substrate, the area where the first surface of the slotted substrate does not contact the cover plate, and the side wall of the through groove. If the area of ​​the hollow portion is completely consistent with the area of ​​the through groove, or the projection area of ​​the hollow portion on the first surface is smaller than the area of ​​the through groove, the second at least partial area is the second surface of the slotted substrate and the side wall of the through groove. For the unremoved carbon attachments on the first surface, the above can be used, which will not be repeated here.

[0090] In a specific embodiment, referring to Figure 4 The through groove 1 is within the projection range of the hollow portion 3 on the first surface, and the distance between the edge of the hollow portion 3 and the edge of the through groove 1 is not greater than 1 mm.

[0091] In this embodiment, the hollow portion 3 of the cover plate 30 is slightly larger than the corresponding through slot 1 through the above arrangement, so that the carbon attachments deposited on the inner side of the through slot 1 and at the junction between the first surface and the through slot 1 can be completely removed, that is, the carbon attachments in the most difficult area to remove in the slotted substrate 10 are removed without damaging the smoothness of the first surface (since the first surface is subsequently used for depositing the resistor film layer, the smoothness requirement is relatively high). The small amount of carbon attachments that may still exist in other areas of the first surface can be easily removed by conventional wiping, brushing, polishing and other methods.

[0092] In a specific embodiment, step S4 of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain a diamond substrate includes:

[0093] S401: Control the hydrogen plasma equipment to heat up to an etching temperature within 30 to 60 minutes, and the etching temperature ranges from 800 to 850° C.;

[0094] S402: maintaining a preset etching time at the etching temperature so that the hydrogen plasma gas etches the second at least a portion of the region, and the etching time is greater than or equal to 20 minutes;

[0095] S403: After etching is completed, the hydrogen plasma equipment is controlled to cool down to a predefined temperature within 30 to 60 minutes, and then naturally cools to room temperature.

[0096] In this embodiment, in the above steps S401 and S403, it is necessary to strictly control the actual heating time and cooling time to prevent the slotted substrate from cracking due to excessive heating or cooling. In the above step 402, the etching time is determined according to the specific specifications of the diamond sheet. When the cover plate is not used, the etching time is controlled at 20-30min. Too long a time will affect the roughness (or smoothness) of the surface of the diamond substrate. If the time is too short, it is not easy to etch the carbon attachments cleanly. When a cover plate is used, the etching time can be appropriately extended. When the etching temperature is above 800°C, the diamond substrate is slightly red but not bright red. The temperature is between 800-850°C. If the temperature is too low, the etching effect is poor. If the temperature is too high, the slotted substrate is easy to crack.

[0097] Furthermore, the gas pressure of the hydrogen plasma equipment is set to 8-12PKa, the power is 6-7KW, and the hydrogen flow rate is 200-400sccm. The above-mentioned predefined temperature is a temperature predefined by humans, which can be a specific temperature value, or a temperature corresponding to when the parameters of the hydrogen plasma equipment drop to a specific value, such as the temperature when the gas pressure of the hydrogen plasma equipment drops to 1Kpa and the power drops to 1KW.

[0098] In a specific embodiment, the etching time is positively correlated with the thickness of the diamond sheet.

[0099] As the thickness of the diamond sheet increases, the etching time increases. Thinner diamond sheets correspond to shorter etching times, and thicker diamond sheets correspond to longer etching times. Specifically, for every 0.1mm increase in the thickness of the diamond sheet, the etching time is extended by 5min, that is, y=20+[(X-X0) / 0.1]*5; wherein y is time, in min; X is the thickness of the diamond sheet, and X0 is the reference thickness of the diamond sheet corresponding to an etching time of 20min, in mm. For example, in a specific embodiment, the reference thickness is 0.254mm. The shorter etching time is in the range of 20 to 30min; the longer etching time is in the range of more than 30min.

[0100] In a specific embodiment, the slotted substrate is placed in a hydrogen plasma device, so that the second at least partial area of ​​the slotted substrate is exposed to hydrogen plasma gas, and before step S3 of the second at least partial area completely or partially overlapping with the first at least partial area, the method includes:

[0101] S31, performing a first cleaning on the slotted substrate to remove powder particles;

[0102] S32, cleaning the slotted substrate for a second time to remove organic oil stains;

[0103] S33, cleaning the slotted substrate for a third time to dehydrate it;

[0104] S34, drying the dehydrated grooved substrate by blowing with inert gas.

[0105] In this embodiment, in the above step S31, the grooved substrate is ultrasonically cleaned in a first organic solvent for 10-30 minutes, and then ultrasonically cleaned in deionized water for 10-30 minutes to remove powder particles. Exemplarily, the first organic solvent used for cleaning powder particles includes organic acids, such as aliphatic monobasic, dibasic, and polybasic carboxylic acids (tartaric acid, oxalic acid, malic acid, citric acid, ascorbic acid, etc.); aromatic organic acids (benzoic acid, salicylic acid, caffeic acid, etc.); preferably, a saturated oxalic acid solution is used.

[0106] In the above step S32, the grooved substrate is ultrasonically cleaned in a second organic solvent for 10-30 minutes, and then ultrasonically cleaned in deionized water for 10-30 minutes to remove organic oil stains. Exemplarily, the second organic solvent used for cleaning organic oil stains includes acetone, ethyl acetate, methanol, isopropanol, chloroform, dichloromethane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, etc.; preferably, acetone is used.

[0107] In the above step S33, the grooved substrate is ultrasonically cleaned in a third organic solvent for 10-30 minutes to dehydrate without residual water stains, and oil / fingerprints and other substances can also be removed. Exemplarily, the third organic solvent used for dehydration includes ethanol, ethylene glycol, isopropanol, acetone, cyclohexanone, etc.; preferably, ethanol is used.

[0108] In the above step S34, the dehydrated grooved substrate is blown dry by an inert gas, for example, the inert gas may include nitrogen, helium, etc.

[0109] In a specific embodiment, step S4 of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain a diamond substrate includes:

[0110] S411: providing hydrogen plasma gas to the grooved substrate, so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region, thereby obtaining a decarbonized substrate;

[0111] S412: performing a first cleaning on the decarbonized substrate to remove powder particles;

[0112] S413: performing a second cleaning on the decarbonized substrate to remove organic oil stains;

[0113] S414: performing a third cleaning on the carbon-removed substrate to dehydrate;

[0114] S415: drying the dehydrated carbon-removed substrate by blowing an inert gas;

[0115] S416: Put the carbon-removed substrate after drying into an oven to obtain a diamond substrate.

[0116] In this embodiment, in the above step S412, the carbon removal substrate is ultrasonically cleaned in a first organic solvent for 10-30 minutes, and then ultrasonically cleaned in deionized water for 10-30 minutes to remove the powder particles. Exemplarily, the first organic solvent used for cleaning the powder particles includes an organic acid, such as aliphatic monobasic, dibasic, and polybasic carboxylic acids (tartaric acid, oxalic acid, malic acid, citric acid, ascorbic acid, etc.); aromatic organic acids (benzoic acid, salicylic acid, caffeic acid, etc.); preferably, a saturated oxalic acid solution is used.

[0117] In the above step S413, the carbon removal substrate is ultrasonically cleaned in a second organic solvent for 10-30 minutes, and then ultrasonically cleaned in deionized water for 10-30 minutes to remove organic oil stains. Exemplarily, the second organic solvent used for cleaning organic oil stains includes acetone, ethyl acetate, methanol, isopropanol, chloroform, dichloromethane, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, etc.; preferably, acetone is used.

[0118] In the above step S414, the carbon-removed substrate is ultrasonically cleaned in a third organic solvent for 10-30 minutes to dehydrate without residual water stains, and oil / fingerprints and other substances can also be removed. Exemplarily, the third organic solvent used for dehydration includes ethanol, ethylene glycol, isopropanol, acetone, cyclohexanone, etc.; preferably, ethanol is used.

[0119] In the above step S415, the dehydrated and carbon-removed substrate is dried by blowing an inert gas, which may include nitrogen, helium, and the like.

[0120] In the above step S416, the carbon-removed substrate after being blown dry by the inert gas is placed in a clean oven and baked at 150-200° C. for 0.5-2 hours to fully dry out the moisture, thereby obtaining a diamond substrate.

[0121] In a specific embodiment, the predefined shape of the through groove includes that the projection of a single through groove on the first surface or the second surface is a closed pattern, the closed pattern includes a middle portion and end portions arranged at both ends of the middle portion, the middle portion is rectangular, and the end portions are arc-shaped.

[0122] In some embodiments, reference Figure 2 The end 101 of the through groove 1 is set to be an arc shape, and the middle part 102 is a rectangle, so that the structural strength of the through groove edge can be improved, and the risk of the diamond substrate cracking during the carbon attachment process can be reduced. For conventional through grooves with right-angled edges, the stress of the right-angled edges is concentrated, and the diamond substrate is prone to cracking at the right angle during the carbon attachment process. The cross-sectional shape of the through groove can be a rectangle, and in other embodiments, it can also be other shapes.

[0123] In some embodiments, the middle portion is a straight line segment, and at the intersection of the arc and the straight line segment, the angle between the tangent of the arc and the straight line segment is α, and the angle α satisfies the following condition: 0°≤α<90°. In other embodiments, the angle α between the tangent of the arc and the straight line segment satisfies the following condition: 30°≤α≤60°. Therefore, by controlling the angle α between the tangent of the arc and the straight line segment to meet the above conditions, especially when the condition range of 30°≤α≤60° is met, the cracking of the through groove during the removal of carbon attachments, that is, the occurrence of cracking of the diamond substrate, can be effectively avoided, thereby improving the reliability of the preparation method.

[0124] The present application discloses a method for preparing a diamond loading, which uses the diamond substrate of any of the above embodiments to prepare a diamond loading, comprising the following steps:

[0125] T1: facing the second surface of the diamond substrate upward, sputtering a first film layer onto the second surface, the first film layer including a metal film layer, as a first substrate;

[0126] T2: facing the first surface of the first substrate upward, sputtering a second film layer onto the first surface, the second film layer including a resistance film layer and a metal film layer, as a second substrate;

[0127] T3: Electroplating the first film layer and the second film layer to thicken the metal film layer as the third substrate;

[0128] T4: performing photolithography etching on the third substrate to pattern the resistance film layer to form a fourth substrate;

[0129] T5: thermally oxidizing the resistance film layer of the fourth substrate and performing a thermal test at a preset temperature for several minutes to tens of minutes to obtain a fifth substrate;

[0130] T6: Perform laser scribing and cutting on the fifth substrate to obtain diamond loading.

[0131] In this embodiment, in the above step T1, the second side of the diamond substrate is placed upward, and a first film layer is sputtered by a magnetron sputtering machine, wherein the first film layer includes at least a metal film layer, such as an Au film layer. In an exemplary embodiment, Ti, Ni, and Au film layers are sputtered respectively, and their thicknesses are 0.1um, 1.2um, and 0.1um, respectively. The diamond substrate after sputtering the first film layer is then cleaned, exemplarily, by ultrasonication in acetone for 10 minutes, overflow ultrasonication in deionized water for 10 minutes, and ultrasonication in anhydrous ethanol for 10 minutes, and then dried with nitrogen and placed in a clean oven at 150°C for 1 hour for standby use. During the sputtering process of the first film layer on the second side, the first film layer material will also be deposited on the sidewalls of the through grooves, thereby forming a metal layer on the sidewalls.

[0132] In the above step T2, the first surface of the diamond substrate is facing upward, and a second film layer is sputtered by a magnetron sputtering machine, wherein the resistance film layer includes, for example, TaN and WTi film layers, and the metal film layer includes, for example, Au film layers. In an exemplary embodiment, TaN, WTi, and Au film layers are sputtered respectively, and the TaN square resistance is designed to be 40-45 ohms / square, and the thicknesses of WTi and Au are 0.1um and 0.1um respectively. Similarly, in the process of sputtering the second film layer on the second surface, the metal film layer material in the second film layer can be controlled to be deposited in the direction of the through-groove side wall to further improve the metal layer forming the side wall.

[0133] In the above step T3, an electroplating system is used to thicken the film layers on the first and second surfaces by electroplating. In an exemplary embodiment, for example, a cyanide gold salt electroplating system is used to thicken the Au film layer to 3.5-4um on the front side and 0.5-1um on the back side to meet the requirements of back welding and front bonding. It is understandable that in this process, the metal layer on the side wall of the through groove is also thickened.

[0134] In the above step T4, the above photolithography etching may be performed once or multiple times. In an exemplary embodiment, the above photolithography etching includes two photolithography etchings, specifically:

[0135] Adopt the glue spraying process, first spray the photoresist on the second side, bake the hard film, then spray the glue on the second side, after the pre-baking is completed, perform the first exposure photolithography, after photolithography, develop, after deionization rinsing, blow dry with nitrogen, and bake the hard film;

[0136] Use Au and WTi etching solution to etch off the Au film first, then rinse it with deionized water, blow it dry with nitrogen, and then etch the WTi film. After etching, remove the glue in the glue remover, rinse it with deionized water, and blow it dry with nitrogen.

[0137] Adopt the glue spraying process, first spray the photoresist on the first side, bake the hard film, then spray the glue on the first side, after the pre-baking is completed, perform the second exposure and overlay, develop after photolithography, blow dry with nitrogen after deionization rinsing, and bake the hard film;

[0138] Use TaN etching solution to etch away the TaN film layer. After completion, remove the glue in the glue removal solution, rinse with deionized water and blow dry with nitrogen.

[0139] In the above step T5, in a specific embodiment, the above thermal oxidation resistance adjustment process includes: in the hot plate atmosphere environment, the temperature is adjusted to 300°C, the TaN resistance accuracy requirement is 50Ω±5%, that is, 47.5-52.2Ω, the resistance adjustment time is 30-60min, and the resistance is tested with an 8-bit half resistance tester to an average resistance of ≥47.5Ω. The above thermal assessment process includes: using a conventional metal electric heating plate that can be heated, first adjusting the temperature of the hot plate to a preset temperature (usually above 300°C, such as 300-350°C), after the temperature reaches the preset temperature, placing the fourth substrate after thermal oxidation resistance adjustment on the hot plate, and starting to time until the preset time is reached and heating is stopped (the thermal assessment time varies according to needs, generally 5-15min, such as 10min), removing the fifth substrate at this time (i.e., the fourth substrate after thermal oxidation resistance adjustment and thermal assessment) from the hot plate, and after it cools down, using a microscope to observe whether there are bubbling, demoulding, etc. on its side. Through thermal testing, the load effect of the metal film layer (especially the side metal layer at the through groove) can be tested.

[0140] In the above step T6, a UV nanosecond laser is used to cut a groove along the center of the unit size edge line, and a splitting machine is used to split the unit into individual load units; preferably, the groove depth is greater than 1 / 2 of the diamond substrate thickness.

[0141] In this embodiment, the diamond load is further prepared using the diamond substrate prepared by the aforementioned method. It can be clearly seen that the carbon attachments before etching are cleaned, and no bubbling or molten residue remains after a 320°C thermal test, and the product yield is greatly improved.

[0142] In some embodiments, after the above step T5, the following may also be included: T7: After the thermal test is completed, the surface and the through grooves of the diamond load are visually inspected under a microscope with a magnification of 50-200 times, and the diamond loads without bubbles or melts in the through grooves are sorted out.

[0143] In some embodiments, after the above step T6, it may also include: T8: Perform visual inspection of the appearance, size, film thickness, bonding strength, and side 3M tape pull test on a single load unit, and put qualified products into storage.

[0144] Some embodiments of the present application disclose a diamond support, which is prepared by the aforementioned diamond support preparation method. Figure 6 The diamond load includes a first surface 51 and a second surface 52 , and a plurality of through grooves 53 are provided on the diamond load. The first surface 51 includes a first metal film layer area 511 and a resistor film layer area 512 , and the second surface 52 includes a second metal film layer area 521 . The side walls of the through grooves 53 are covered with a side metal film layer 531 .

[0145] The diamond load of this embodiment does not produce bubbles or molten residue after a 320° C. thermal test, and the product yield is greatly improved.

[0146] The following is a comparative explanation through specific embodiments and comparative examples.

[0147] Embodiment 1

[0148] Grooving process:

[0149] (1) A circular diamond sheet with a thickness of 0.381 mm and a diameter of 65 mm was selected, and a through groove was cut on the diamond sheet using a UV nanosecond laser cutting machine. The width of the groove was 0.2 mm, the edge of the groove was semicircular, and the distance between the arc and the edge of the substrate was 3.5 mm. After laser cutting, the grooved substrate was wiped back and forth twice with a dust-free cloth dipped in alcohol. After wiping, it was placed in an alcohol tank for ultrasonic treatment for 10 min, and then dried with nitrogen to obtain the grooved substrate.

[0150] Etching carbon deposits process:

[0151] (2) Use a dust-free cloth dipped in alcohol to wipe the first and second surfaces of the slotted substrate back and forth 5-10 times until there is no black dirt on the dust-free cloth. After wiping, ultrasonicate in acetone for 10 minutes, overflow ultrasonicate in deionized water for 10 minutes, ultrasonicate in anhydrous ethanol for 10 minutes, and blow dry with nitrogen.

[0152] (3) Place the cleaned slotted substrate on a molybdenum sheet with a lateral boss to form a gap under the slotted substrate with a gap height of 0.5 mm; after the MPCVD equipment is cleaned, place the molybdenum sheet with the slotted substrate into the equipment, vacuum clean it, turn on the power of the equipment and preheat the filament, and after the equipment is ignited at 1KW and 1Kpa, set the automatic temperature rise, and set the temperature rise cutoff parameters to: 6KW, 9Kpa, temperature 800°C, hydrogen flow rate 200sccm, temperature rise time 30min, start timing after the temperature reaches 800°C, etching time 30min, and automatically cool down and take out 30min after etching to obtain a decarbonized substrate.

[0153] (4) The decarbonized substrate was cleaned again, first by ultrasonic treatment with acetone for 10 min, ultrasonic treatment with deionized water for 10 min, and ultrasonic treatment with anhydrous ethanol for 10 min. After drying with nitrogen, the substrate was placed in a clean oven and baked at 150° C. for 1 h to obtain a cleaned diamond substrate with clean through grooves.

[0154] Diamond loading preparation process:

[0155] (5) With the second surface of the diamond substrate facing upward, a magnetron sputtering machine was used to sputter Ti, Ni, and Au film layers, with thicknesses of 0.1 um, 1.2 um, and 0.1 um, respectively.

[0156] (6) The diamond substrate after sputtering Ti, Ni, and Au film layers was ultrasonically treated in acetone for 10 minutes, in deionized water overflow for 10 minutes, and in anhydrous ethanol for 10 minutes. After being blown dry with nitrogen, the substrate was placed in a clean oven and baked at 150° C. for 1 hour for use as the first substrate.

[0157] (7) With the first surface of the first substrate facing upward, TaN, WTi, and Au film layers are sputtered respectively using a magnetron sputtering machine, wherein the TaN square resistance is designed to be 40-45 ohms / square, and the thicknesses of the WTi film layer and the Au film layer are 0.1 um and 0.1 um respectively.

[0158] (8) Using a cyanide gold salt electroplating system, the double-sided film layer is electroplated to thicken to 3.5-4um on the front side and 0.5-1um on the back side to meet the requirements of back welding and front bonding.

[0159] (9) Using the spray glue process, first spray glue on the second side, bake the hard film, and then spray glue on the first side. After the pre-bake is completed, the first exposure lithography is performed, and after lithography, it is developed, deionized and rinsed, and then dried with nitrogen, and baked to harden the film.

[0160] (10) Use Au and WTi etching solutions to first etch off the Au film layer, then rinse it in deionized water, blow dry it with nitrogen, and then etch the WTi film layer. After etching, remove the glue in the degumming solution, rinse it with deionized water, and blow dry it with nitrogen.

[0161] (11) The glue spraying process is adopted. The back side is first sprayed with glue. After the hard film is baked, the glue is sprayed on the front side again. After the pre-baking is completed, the second exposure and overlay are performed. After photolithography, the development is performed, the deionized water is rinsed, and the nitrogen is blown dry, and the hard film is baked.

[0162] (12) Use TaN etching solution to etch away the TaN film layer. After completion, remove the glue in the glue removal solution, rinse with deionized water, and blow dry with nitrogen.

[0163] (13) The resistance on the front side of the etched diamond substrate is thermally oxidized and adjusted. In the hot plate atmosphere, the temperature is controlled at 300°C. The TaN resistance accuracy requirement is 50Ω±5%, i.e., 47.5-52.2Ω. The adjustment time is 30-60min. The resistance is tested with an 8-bit half-value resistance tester until the average resistance is ≥47.5Ω. Then, the hot plate temperature is adjusted to 320°C. The substrate is taken out after 5 minutes of thermal testing.

[0164] (14) After the thermal assessment is completed, the substrate surface and channels are visually inspected under a microscope at 50-200 times magnification.

[0165] (15) A UV nanosecond laser is used to cut a groove with a depth greater than 1 / 2 of the substrate thickness along the center of the load unit size edge line, and a splitting machine is used to split the load units into individual load units.

[0166] (16) Conduct 100% visual inspection of appearance, size, film thickness, bonding strength, and side 3M tape pull-out test on each load unit, and qualified products will be put into storage.

[0167] Comparative Example 1

[0168] The groove opening process and diamond loading preparation process of Comparative Example 1 are the same as those of Example 1, except that the carbon attachment removal process adopts the following steps:

[0169] Use chromic acid to heat to 70℃ and ultrasonicate for 10 minutes;

[0170] Use 20% hydrofluoric acid at room temperature and ultrasonic for 10 minutes;

[0171] Rinse with deionized water for 2 minutes;

[0172] 3% alkaline surfactant was used, heated to 80°C, and ultrasonicated for 20 minutes;

[0173] Rinse with deionized water 3 times;

[0174] Heat to 80°C with hot water and ultrasonicate for 20 minutes;

[0175] Rinse with deionized water 6 times;

[0176] Use anhydrous ethanol at room temperature and ultrasonicate for 10 minutes;

[0177] The substrate was baked at 100° C. for 1 hour.

[0178] The diamond substrate prepared in Example 1 after grooving and cleaning was observed under a microscope near the through grooves. The results are as follows: Figure 7 As shown, Figure 7 (a) is a picture of the area near the through slot before cleaning, showing that there are many black carbon deposits attached to its surface; Figure 7 (b) is a picture of the area near the through slot after cleaning. Its surface is white and has no black attachments. It can be clearly seen that the carbon attachments have been cleaned. Figure 7 (a) and Figure 7 From the comparison with (b) in FIG. 1 , it can be seen that the processing method of the diamond substrate provided in the embodiment of the present application has a good effect of removing carbon attachments.

[0179] After the thermal test of the diamond load prepared in Example 1 and the diamond load prepared in Comparative Example 1 in step (14) was completed, the film adhesion effect at the diamond load groove was observed under a microscope as follows: Figure 8 shown. Figure 8 (a) and (b) are partial pictures of diamond loading prepared in Comparative Example 1. Figure 8(c) and (d) are partial pictures of the diamond loading prepared in Example 1. Figure 8 As can be seen in (a), there is obvious bubbling in the direction indicated by the arrow. Figure 8 The oval area in (b) has obvious slag residue; Figure 8 The metal film layer attached to the through groove in (c) and (d) is intact, no bubbling phenomenon occurs, and no residual melt residue is observed. It can be seen that the diamond load provided in the embodiment of the present application has good adhesion on the diamond substrate, especially on the side wall of the diamond basic through groove after thermal assessment. Compared with the comparative example 1, the yield of the diamond load is greatly improved, and it has good economic value and promotion value. It is shown that compared with the prior art, the diamond substrate obtained by the processing method of the diamond substrate provided in the embodiment of the present application has a good cleaning effect on the carbon attachments attached to the side wall of the through groove, which is conducive to metal coating thereon, etc., and can effectively improve the yield and reliability of products manufactured therefrom, such as diamond loads.

[0180] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A method for preparing a diamond substrate, characterized in that: The steps include: providing a diamond sheet having opposing first and second faces; A through groove of a predefined shape is opened on the diamond sheet by a laser cutting method, and the through groove penetrates the diamond sheet from the first surface to the second surface to obtain a grooved substrate; wherein the surface of the grooved substrate includes the first surface, the second surface and the side wall of the through groove, and the first at least partial area of ​​the surface of the grooved substrate is covered with carbon attachments, and the first at least partial area includes the side wall of the through groove; the predefined shape of the through groove includes that the projection of a single through groove on the first surface or the second surface is a closed pattern, and the closed pattern includes a middle part and end parts arranged at both ends of the middle part, the middle part is rectangular, and the end parts are arc-shaped; the width of the through groove is 0.2-0.25 mm; The slotted substrate is placed in a hydrogen plasma device, and the second surface of the slotted substrate is placed on a carrier, which is arranged in the hydrogen plasma device, so that the second at least partial area of ​​the slotted substrate is exposed to the hydrogen plasma gas, and the second at least partial area completely overlaps or partially overlaps with the first at least partial area; the second at least partial area at least includes a through-groove side wall; a plurality of convex ribs are arranged at intervals on the upper surface of the carrier, the second surface of the slotted substrate is in direct contact with the upper surface of the convex rib, and the through-groove of the slotted substrate intersects with the convex rib; or a plurality of grooves are arranged at intervals on the upper surface of the carrier, the second surface of the slotted substrate is in direct contact with the upper surface of the carrier, and the through-groove of the slotted substrate intersects with the groove; A hydrogen plasma gas is provided to the grooved substrate so that the hydrogen plasma gas etches the second at least partial area to remove carbon attachments in the second at least partial area to obtain the diamond substrate. The etching temperature ranges from 800 to 850° C., and the etching time is 20 to 30 minutes. During the etching process, the gas pressure of the hydrogen plasma equipment is set to 8 to 12 kPa, and the power is 6 to 7 kW.

2. The method for preparing a diamond substrate according to claim 1, wherein: After the step of placing the second surface of the grooved substrate on a carrier, and the carrier is arranged in the hydrogen plasma equipment, the method comprises: A cover plate is arranged on the first surface of the slotted substrate, and the cover plate is provided with hollow parts corresponding to the through slots one by one. The cover plate is adjusted so that each hollow part corresponds to the corresponding through slot one by one, so that the side wall of the through slot is exposed to the hydrogen plasma gas.

3. The method for preparing a diamond substrate according to claim 2, wherein: The through slot is within the projection range of the hollow portion on the first surface, and the distance between the edge of the hollow portion and the edge of the through slot is no more than 1 mm.

4. The method for preparing a diamond substrate according to claim 1, wherein: The step of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain the diamond substrate comprises: Controlling the hydrogen plasma equipment to heat up to an etching temperature within 30 to 60 minutes, wherein the etching temperature ranges from 800 to 850° C.; Maintaining a preset etching time at the etching temperature so that the hydrogen plasma gas etches the second at least partial region, the etching time being greater than or equal to 20 minutes; After etching is completed, the hydrogen plasma equipment is controlled to cool down to a predefined temperature within 30 to 60 minutes, and then naturally cools down to room temperature.

5. The method for preparing a diamond substrate according to claim 4, characterized in that: The etching time is positively correlated with the thickness of the diamond sheet.

6. The method for preparing a diamond substrate according to claim 1, wherein: Before the step of placing the slotted substrate into a hydrogen plasma device to expose the second at least partial region of the slotted substrate to hydrogen plasma gas, wherein the second at least partial region completely overlaps or partially overlaps with the first at least partial region, the method comprises: performing a first cleaning on the slotted substrate to remove powder particles; Cleaning the grooved substrate for a second time to remove organic oil stains; performing a third cleaning on the grooved substrate to dehydrate; The dehydrated grooved substrate is blown dry by inert gas.

7. The method for preparing a diamond substrate according to claim 1, wherein: The step of providing hydrogen plasma gas to the grooved substrate so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain the diamond substrate comprises: Providing hydrogen plasma gas to the grooved substrate, so that the hydrogen plasma gas etches the second at least partial region to remove carbon attachments in the second at least partial region to obtain a decarbonized substrate; performing a first cleaning on the decarbonized substrate to remove powder particles; Performing a second cleaning on the carbon removal substrate to remove organic oil stains; performing a third cleaning on the decarbonized substrate to dehydrate; Blowing the dehydrated carbon-removed substrate dry with inert gas; The decarbonized substrate after drying is placed in an oven for drying to obtain the diamond substrate.

8. A diamond substrate, characterized in that: The diamond substrate is prepared by the method for preparing the diamond substrate as described in any one of claims 1 to 7.

9. A method for preparing a diamond support, characterized in that: The preparation of the diamond support using the diamond substrate as claimed in claim 8 comprises the following steps: The second surface of the diamond substrate faces upwards, and a first film layer is sputtered onto the second surface, wherein the first film layer includes a metal film layer, as a first substrate; Place the first surface of the first substrate upward, and sputter a second film layer onto the first surface, wherein the second film layer includes a resistance film layer and a metal film layer, to serve as a second substrate; Electroplating the first film layer and the second film layer to thicken the metal film layer to serve as a third substrate; Performing photolithography and etching on the third substrate to pattern the resistance film layer to form a fourth substrate; The resistance film layer of the fourth substrate is subjected to thermal oxidation resistance adjustment, and thermal testing is performed at a preset temperature for several minutes to tens of minutes to obtain a fifth substrate; The fifth substrate is laser scribing and cutting to obtain the diamond loading.

10. A diamond support, characterized in that: The diamond-supported material is prepared by the method for preparing the diamond-supported material as claimed in claim 9.

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