A highly stable diamond crystal growth molybdenum stage

Abstract

This invention discloses a highly stable diamond crystal growth molybdenum stage, comprising: a molybdenum stage body, wherein the lower surface edge of the molybdenum stage body protrudes downward to form a ring block that cooperates with an external water-cooling stage; a support panel, detachably connected to the molybdenum stage body; a limiting protrusion integrally formed on the support panel to limit its movement range during diamond crystal growth; and a heat-conducting structure disposed inside a mounting groove opened on the lower surface of the molybdenum stage body. This invention, through the detachable cooperation between the support panel and the molybdenum stage body, and the limiting protrusion, facilitates the individual replacement of the support panel according to actual needs, reducing waste caused by overall scrapping. Optimized heat conduction facilitates better heat transfer to the edge of the molybdenum stage and heat exchange with the water-cooling stage, greatly improving the uniformity of the overall heat distribution of the molybdenum stage. Furthermore, the high thermal conductivity also facilitates effective heat control of the molybdenum stage.

Description

Technical Field

[0001] This invention specifically relates to a highly stable diamond crystal growth molybdenum stage. Background Technology

[0002] Due to its excellent physical and chemical properties, single-crystal diamond has broad application prospects in precision machining, electronic devices and quantum communication. In the production process of synthetic single-crystal diamond, the molybdenum stage, as the core component that carries the diamond seed crystal, directly affects the crystal growth quality and production efficiency. Commonly used molybdenum stages are mostly made of pure molybdenum and adopt an integral structure design. During use, the molybdenum stage is placed in the crystal growth furnace, and the temperature is controlled by the water-cooled stage on the lower surface of the molybdenum stage. The seed crystal is placed on its working surface, and the epitaxial growth of diamond is completed in a high-temperature environment.

[0003] Due to the inherent thermal conductivity of molybdenum and the limitations of the molybdenum stage structure, traditional molybdenum stages are prone to thermal field phenomena with high center temperature and low edge temperature under high-temperature environments. This leads to uneven heating of the seed crystal, which in turn causes thermal stress accumulation in the grown single crystal diamond, resulting in crack defects and seriously affecting the yield of finished products. Furthermore, molybdenum stages are mostly one-piece structures. When the working surface is difficult to clean or damaged due to deposits, the entire molybdenum stage is often scrapped, and it is impossible to replace the key bearing surface separately. Therefore, we propose a highly stable diamond crystal growth molybdenum stage. Summary of the Invention

[0004] The purpose of this invention is to provide a highly stable diamond crystal growth molybdenum stage to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a highly stable diamond crystal growth molybdenum stage, comprising:

[0006] The molybdenum stage body has a ring block formed by the downward protrusion of the lower edge of the molybdenum stage body, which cooperates with the external water-cooling stage.

[0007] A support panel is detachably connected to the molybdenum stage body;

[0008] A limiting protrusion is integrally formed on the support panel to limit its range of movement during diamond crystal growth.

[0009] A heat-conducting structure is disposed inside the mounting groove opened on the lower surface of the molybdenum stage body, and the lower surface of the heat-conducting structure is flush with the lower surface of the molybdenum stage body, so as to better diffuse the heat of the molybdenum stage body to the edge and conduct heat to the water-cooled stage.

[0010] Preferably, the heat-conducting structure includes a heat-conducting column and a heat-conducting plate. The heat-conducting column is connected to the inner side of the mounting groove by an interference fit, and a heat-conducting plate is provided on the outer wall of the heat-conducting column along its circumference.

[0011] Preferably, four heat-conducting plates are provided, and the lower surface of the heat-conducting plates is flush with the lower surface of the molybdenum platform body.

[0012] Preferably, the edge of the support panel is bent downward to form a skirt, and the molybdenum platform body has a threaded groove corresponding to the skirt and threadedly connected to the skirt. The lower surface of the support panel is integrally formed with a raised strip, and the upper surface of the molybdenum platform body has a connecting groove that cooperates with the raised strip.

[0013] Preferably, there are multiple protrusions along the radial direction of the support panel, and the multiple protrusions are concentric rings.

[0014] Preferably, the inner center thickness of the molybdenum platform body is α, the edge thickness is β, and the thickness α is at least twice the thickness β.

[0015] Preferably, the lower surface of the molybdenum platform body has a plurality of concentric heat dissipation annular grooves along its radial direction.

[0016] Preferably, the lower end of the inner surface of the ring block has a chamfer.

[0017] Preferably, the outer diameter of the molybdenum stage body and the support panel are the same, and both the molybdenum stage body and the support panel are made of lanthanum-doped molybdenum alloy.

[0018] Preferably, the surface of the support panel has an antioxidant coating.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] (1) The present invention avoids the waste of the entire molybdenum stage when the contact surface with the diamond is difficult to clean due to the detachable cooperation between the support panel and the molybdenum stage body and the limiting protrusion. The traditional molybdenum stage is an integral structure. This device is convenient to replace the support panel separately according to actual needs, reducing the waste caused by the overall waste. The structure is simple and can keep the position of the diamond unchanged through the limiting protrusion, reducing the slippage on the surface of the molybdenum stage and the diamond overlap. In addition, the lanthanum doped molybdenum alloy material and the anti-oxidation coating on the surface are conducive to improving the convenience of cleaning and can significantly increase the number of times the molybdenum stage can be reused and reduce the frequency of replacement.

[0021] (2) By setting up heat-conducting columns and heat-conducting plates, it is convenient to transfer heat to the edge of the molybdenum stage and achieve heat exchange with the water-cooled stage. This avoids the traditional single molybdenum material, poor thermal conductivity, inability to control the temperature of the molybdenum stage, hot spots, and uneven heat distribution. The structure of this device is simple, which is conducive to achieving efficient heat conduction and greatly improves the uniformity of the overall heat distribution of the molybdenum stage. The high thermal conductivity is also conducive to the effective control of the heat of the molybdenum stage. The uniform thermal field can effectively reduce the internal stress of diamond and ensure the qualification rate of finished products. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0024] Figure 3 This is a schematic diagram of the exploded structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the support panel structure of the present invention;

[0026] Figure 5 This is a schematic diagram of the installation of the heat-conducting structure of the present invention;

[0027] Figure 6 This is a schematic diagram of the thickness of the molybdenum stage body structure of the present invention.

[0028] In the figure: 1. Molybdenum platform body; 101. Ring block; 102. Chamfer; 103. Threaded groove; 104. Connecting groove; 105. Mounting groove; 106. Ring groove; 2. Support panel; 201. Raised strip; 202. Skirt; 3. Limiting protrusion; 4. Heat-conducting structure; 401. Heat-conducting column; 402. Heat-conducting plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1-6 This invention provides a technical solution: a highly stable diamond crystal growth molybdenum stage, comprising:

[0031] The molybdenum stage body 1 has a ring block 101 that mates with an external water-cooling stage, with the lower edge of the molybdenum stage body 1 protruding downwards.

[0032] Support panel 2 is detachably connected to molybdenum stage body 1;

[0033] The limiting protrusion 3 is integrally formed on the support panel 2 to limit its range of movement during diamond crystal growth;

[0034] The limiting protrusion 3 is used to limit the displacement of diamond on the support panel 2, avoid disturbance of the reaction airflow, and prevent repeated heating and cooling from causing the etched carbon atoms to deposit on the back of the seed crystal, resulting in reduced back flatness and increased surface lubricity, which in turn causes the seed crystal to drift from the preset position or even overlap.

[0035] Furthermore, the detachable connection between the support panel 2 and the molybdenum stage body 1 in this invention prevents the upper surface of the molybdenum stage from reacting with carbon in a high-temperature plasma environment, which would form a tightly bonded and chemically stable deposit on the surface of the molybdenum support. This deposit would be difficult to remove later, causing the entire molybdenum stage to be scrapped. This device can replace the upper surface of the molybdenum stage body 1 separately, reducing the waste of overall scrapping.

[0036] The heat conduction structure 4 is located inside the mounting groove 105 opened on the lower surface of the molybdenum stage body 1, and the lower surface of the heat conduction structure 4 is flush with the lower surface of the molybdenum stage body 1, so as to better diffuse the heat of the molybdenum stage body 1 to the edge and conduct heat to the water-cooled stage.

[0037] The heat-conducting structure 4 is preferably made of copper, tungsten copper composite material or silicon carbide. The heat-conducting structure 4 is flush with the heat dissipation surface of the lower surface of the molybdenum stage body 1, which does not affect the assembly compatibility and facilitates heat exchange between the molybdenum stage body 1 and the water-cooled stage. This helps to control the temperature of the molybdenum stage. Utilizing the thermal conductivity of the heat-conducting structure 4, which is higher than that of molybdenum material, the temperature difference across the entire working surface can be controlled within 20°C. This effectively eliminates the accumulation of thermal stress during the seed crystal growth process, ensures the uniformity of the thermal field distribution of the entire molybdenum stage, and guarantees the consistency of the synchronous growth of multiple seed crystals.

[0038] Preferably, the heat-conducting structure 4 includes a heat-conducting column 401 and a heat-conducting plate 402. The heat-conducting column 401 is connected to the inner side of the mounting groove 105 by an interference fit, and the heat-conducting plate 402 is provided on the outer wall of the heat-conducting column 401 along its circumference.

[0039] The heat-conducting columns 401 and heat-conducting plates 402, which have better thermal conductivity, facilitate the transfer of heat to the water-cooled stage on the lower surface of the molybdenum stage body 1, or diffuse the heat from the center of the molybdenum stage body 1 to the edge, so that the heat distribution is uniform.

[0040] Preferably, four heat-conducting plates 402 are provided, and the lower surface of the heat-conducting plates 402 is flush with the lower surface of the molybdenum platform body 1;

[0041] This allows for a better heat conduction area and a better contact area with the external water-cooling platform, thereby ensuring excellent heat conduction efficiency.

[0042] Preferably, the edge of the support panel 2 is bent downward to form a skirt 202, and a threaded groove 103 corresponding to the skirt 202 is provided on the molybdenum platform body 1 for threaded connection with the skirt 202. A protrusion 201 is integrally formed on the lower surface of the support panel 2, and a connecting groove 104 that cooperates with the protrusion 201 is provided on the upper surface of the molybdenum platform body 1.

[0043] The protrusion 201 cooperates with the connecting groove 104 to increase the thermal contact area, thereby ensuring good heat conduction. The detachable connection between the support panel 2 and the molybdenum stage body 1 facilitates the replacement and maintenance of the support panel 2 separately in the future.

[0044] Preferably, there are multiple protrusions 201 along the radial direction of the support panel 2, and the multiple protrusions 201 are concentric rings;

[0045] The outer surface area of ​​the protrusion 201 is used to increase the heat conduction area between the support panel 2 and the molybdenum platform body 1, thereby improving the uniformity of heat transfer distribution.

[0046] Preferably, the thickness at the center of the inner side of the molybdenum stage body 1 is α, the thickness at the edge is β, and the thickness α is at least twice the thickness β;

[0047] By increasing the thickness of the molybdenum stage center, the localized high heat at the center of the stage can be conducted downwards along the thickness direction for a short period, then diffused laterally to the surrounding area, and then carried away by the cooling water of the bottom water-cooled stage. This makes the temperature distribution on the stage surface more uniform, avoiding the situation where the stage is too thin, resulting in a small heat storage capacity and limited heat transfer capacity in the lateral direction parallel to the stage. The heat flux density from the plasma center is high. If the heat cannot be quickly spread laterally to the entire stage, a noticeable hot spot will form at the center of the stage.

[0048] By reducing the thickness of the molybdenum stage's edges, thermal resistance is reduced, allowing for faster heat transfer. This enables the high temperature at the center of the stage to quickly diffuse to the edges, resulting in a more uniform heat distribution across the entire stage. Heat can also be transferred more quickly from the hot side of the stage to the cold side of the water-cooled stage, facilitating better control of the edge temperature. In short, for achieving rapid heat dissipation and reducing the overall stage temperature, a thinner stage is better for thermal conductivity; however, to maintain a uniform and stable stage temperature and avoid localized overheating, a certain thickness of the stage is required.

[0049] Preferably, the lower surface of the molybdenum platform body 1 has a plurality of concentric heat dissipation annular grooves 106 along its radial direction;

[0050] By increasing the heat dissipation area at the edge, the uniformity of the thermal field distribution is further optimized, ensuring the consistency of synchronous growth of multiple seed crystals.

[0051] Preferably, the lower end of the inner surface of the ring block 101 has a chamfer 102;

[0052] To facilitate better assembly of the molybdenum stage body 1 onto the top of the water-cooled stage, a chamfer 102 is used for guidance. The water-cooled stage can be the one disclosed in CN222729898U, entitled "A Water-Cooled Stage in a Diamond Growth Molybdenum Stage Structure". The inner wall of the corresponding ring block 101 can be machined with threaded grooves to better connect with the water-cooled stage.

[0053] Preferably, the outer diameters of the molybdenum stage body 1 and the support panel 2 are the same, and both the molybdenum stage body 1 and the support panel 2 are made of lanthanum-doped molybdenum alloy.

[0054] Abandoning the traditional pure molybdenum substrate, a lanthanum-doped molybdenum alloy (La-Mo) is adopted. Through the dispersion strengthening effect of the rare earth element lanthanum, the room temperature tensile strength of the substrate is increased by 40% compared with that of pure molybdenum. The high temperature stability is significantly optimized, and it can withstand multiple high-temperature sintering and cooling cycles without deformation. It maintains the flatness accuracy of the working surface for a long time, and the number of cycles can be increased from about 20 to more than 50 compared with the traditional pure molybdenum stage, extending the service life by more than 2 times and reducing the replacement frequency.

[0055] Preferably, the surface of the support panel 2 has an anti-oxidation coating;

[0056] After precision polishing, the working surface is treated with an anti-oxidation coating. This process reduces surface adhesion energy, inhibits oxidation reactions and impurity deposition under high-temperature conditions, and simplifies subsequent cleaning and maintenance.

[0057] The working principle and usage process of this invention are as follows: The molybdenum stage body 1 is embedded into the preset installation position in the crystal growth furnace, so that the lower surface of the molybdenum stage body 1 is in close contact with the furnace heat dissipation components or water-cooled stage to form a good heat conduction path. The support panel 2 is installed on the molybdenum stage body 1. Diamond seed crystals are evenly laid on the upper surface of the support panel 2, i.e., the working surface. During the laying, the limiting protrusions 3 are used to position and separate the seed crystals to prevent the seed crystals from sliding horizontally or overlapping in subsequent processes. Then the crystal growth process can be started. During the crystal growth process, the heat conduction structure 4 quickly conducts excess heat from the central area. Combined with the variable thickness design of the molybdenum stage body 1 and the heat dissipation ring groove 106 on the lower surface, the temperature difference of the support panel 2 is controlled within 20°C, effectively eliminating the accumulation of thermal stress and ensuring the consistency of the synchronous growth of multiple seed crystals. After the crystal growth is completed, the molybdenum stage is removed and its working surface is cleaned. When the support panel 2 is worn due to long-term use, the anti-oxidation coating fails, or the surface deposits are difficult to remove completely, it can be replaced separately without discarding the entire molybdenum stage.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A highly stable diamond-grown molybdenum stage, characterized in that, include: The molybdenum stage body (1) has a ring block (101) that bulges downward on the lower edge of the molybdenum stage body (1) to cooperate with the external water-cooling stage. The support panel (2) is detachably connected to the molybdenum stage body (1); The limiting protrusion (3) is integrally formed on the support panel (2) to limit its range of movement during diamond crystal growth; A heat-conducting structure (4) is provided inside the mounting groove (105) opened on the lower surface of the molybdenum stage body (1), and the lower surface of the heat-conducting structure (4) is flush with the lower surface of the molybdenum stage body (1) so as to better diffuse the heat of the molybdenum stage body (1) to the edge and conduct heat to the water-cooled stage.

2. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The heat-conducting structure (4) includes a heat-conducting column (401) and a heat-conducting plate (402). The heat-conducting column (401) is connected to the inner side of the mounting groove (105) by an interference fit, and the outer wall of the heat-conducting column (401) is provided with a heat-conducting plate (402) along its circumference.

3. The highly stable diamond crystal growth molybdenum stage according to claim 2, characterized in that: Four heat-conducting plates (402) are provided, and the lower surface of the heat-conducting plates (402) is flush with the lower surface of the molybdenum platform body (1).

4. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The edge of the support panel (2) is bent downward to form a skirt (202). The molybdenum platform body (1) is provided with a threaded groove (103) corresponding to the skirt (202) and threadedly connected to the skirt (202). The lower surface of the support panel (2) is integrally formed with a protrusion (201). The upper surface of the molybdenum platform body (1) has a connecting groove (104) that cooperates with the protrusion (201).

5. The highly stable diamond crystal growth molybdenum stage according to claim 4, characterized in that: The convex strip (201) has multiple radially along the support panel (2), and the multiple convex strips (201) are concentric rings.

6. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The inner center thickness of the molybdenum platform body (1) is α, the edge thickness is β, and the thickness α is at least twice the thickness β.

7. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The lower surface of the molybdenum platform body (1) has a plurality of concentric heat dissipation annular grooves (106) along its radial direction.

8. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The lower end of the inner surface of the ring block (101) has a chamfer (102).

9. The high-stability diamond crystal growth molybdenum stage according to claim 1, characterized in that: The molybdenum stage body (1) and the support panel (2) have the same outer diameter, and both the molybdenum stage body (1) and the support panel (2) are made of lanthanum-doped molybdenum alloy.

10. A highly stable diamond crystal growth molybdenum stage according to claim 2, characterized in that: The surface of the support panel (2) has an anti-oxidation coating.

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