Device for uniformizing polycrystalline or monocrystalline diamond growth temperature field and diamond growth method

Abstract

The invention provides a device for uniformizing a polycrystalline or monocrystalline diamond growth temperature field and a diamond growth method, and relates to the field of polycrystalline or monocrystalline diamond crystals. The device comprises a growth support, a substrate sheet and a plurality of heat dissipation adjusting sheets which can be stacked in sequence, the substrate sheet is arranged at the top of the growth support and used for depositing diamond, and the growth support is used for being placed on a heat dissipation table with a cooling water channel; a heat dissipation groove is formed in the bottom of the growth support, and a connecting column is arranged in the heat dissipation groove; connecting through holes are formed in the heat dissipation adjusting pieces, and the connecting columns are detachably connected with the connecting through holes. According to the shape and distribution of the temperature field of the diamond deposition area, the heat dissipation adjusting fins with the corresponding shape and number can be installed, so that the heat conductivity of the area with the high temperature of the inner ring in the temperature field of the diamond deposition area is high, and the heat conductivity of the area with the low temperature of the outer ring in the temperature field of the diamond deposition area is low; and the temperature field of the diamond deposition area is kept balanced.

Description

Technical Field

[0001] The present invention relates to the field of polycrystalline or single crystal diamond crystals, in particular to a device for uniform polycrystalline or single crystal diamond growth temperature field and a diamond growth method. Background Art

[0002] Diamond has an ultra-wide spectral transmittance range, excellent optical transmittance, ultra-high hardness and thermal conductivity, extremely low thermal expansion coefficient, and low dielectric loss. It can meet the application requirements of window materials from X-ray, deep ultraviolet to microwave bands, and has become the first choice material for optical devices under extreme conditions such as X-ray windows, infrared guidance windows, high-power CO2 laser windows, and high-energy microwave feed windows.

[0003] Currently, the most mature method for growing polycrystalline diamond sheets is microwave plasma chemical vapor deposition (MPCVD). However, in the actual MPCVD diamond growth process, due to variations in plasma shape and material ionization deposition rate, it is common to encounter uneven temperature fields in the diamond deposition area under changes in power, pressure, and airflow. This leads to inconsistent diamond growth environments in different areas, resulting in uneven thickness and color differences between the inner and outer circles, reducing the growth yield. Furthermore, for growing large-scale polycrystalline or single crystal diamonds, uneven thickness also increases the difficulty of subsequent processing, significantly reducing the qualified rate of the finished product.

[0004] Currently, during the actual diamond deposition and growth process, the temperature in the center of the diamond growth temperature field is higher than that in non-central areas, and the high-temperature central region is generally asymmetrically circular. The shape and size of the high-temperature central region in the diamond growth temperature field vary depending on the machine and process. Current devices used to establish a uniform diamond growth temperature field are all integrally formed, resulting in a narrow range of process adaptability. This directly leads to problems such as high consumables costs, long processing cycles, and difficulty in machining targeted, irregularly shaped cooling zones.

[0005] Therefore, there is an urgent need for a device that can be flexibly adjusted to balance the growth temperature field. Summary of the Invention

[0006] In order to solve the above problems, the first aspect of the present invention provides a device for uniformly growing a temperature field of polycrystalline or single crystal diamond, which can balance the temperature field of the diamond deposition area and significantly reduce costs.

[0007] The device for growing temperature field of uniform polycrystalline or single crystal diamond provided by the application comprises a growth holder, a substrate sheet and a plurality of heat dissipation adjusting sheets which can be placed in sequence, the substrate sheet is arranged on the top of the growth holder and used for depositing diamond, and the growth holder is used for being placed on a heat dissipation table containing a cooling water channel; the bottom of the growth holder is provided with a heat dissipation groove, and a connecting column is arranged in the heat dissipation groove; a connecting through hole is arranged in the heat dissipation adjusting sheet, and the connecting column and the connecting through hole are detachably connected, and a plurality of heat dissipation adjusting sheets can be arranged in sequence in the heat dissipation groove.

[0008] In an implementable embodiment, the center point of the heat dissipation groove is located on the center axis of the connecting column, and the center axis of the connecting column coincides with the center axis of the growth holder.

[0009] In an implementable embodiment, the shape of the heat dissipation adjusting sheet is selected from any one of a cylinder, an elliptical cylinder or a polygonal cylinder.

[0010] In an implementable embodiment, the heat dissipation adjusting sheet is an elliptical cylinder, the major axis of the heat dissipation adjusting sheet is 5-12 mm, the minor axis of the heat dissipation adjusting sheet is 5-10 mm, and the thickness of the heat dissipation adjusting sheet is 1-8 mm.

[0011] In an implementable embodiment, the shape of the growth holder is a cylinder or an elliptical cylinder; and the shape of the heat dissipation groove is a cylindrical groove or an elliptical cylindrical groove.

[0012] In an implementable embodiment, the shape of the growth holder is a cylinder, the diameter of the growth holder is 110-140 mm, and the height of the growth holder is 9-15 mm; the shape of the heat dissipation groove is a cylindrical groove, the diameter of the heat dissipation groove is 70-100 mm, and the depth of the heat dissipation groove is 1-8 mm.

[0013] In an implementable embodiment, the material of the heat dissipation adjusting sheet is metal or alloy.

[0014] In an implementable embodiment, the material of the growth holder is metal or alloy.

[0015] In an implementable embodiment, the material of the substrate sheet is selected from any one of silicon polycrystal / silicon single crystal, germanium polycrystal / germanium single crystal, silicon carbide polycrystal / silicon carbide single crystal, gallium nitride polycrystal / gallium nitride single crystal, aluminum nitride polycrystal / aluminum nitride single crystal, diamond polycrystal / diamond single crystal, or a plurality of combinations of the above materials, or a plated film material.

[0016] The second aspect of the application provides a diamond growth method, which adopts the device for growing temperature field of uniform polycrystalline or single crystal diamond provided by the first aspect of the application, and comprises the following steps:

[0017] Step 1) determining a high-temperature region on the substrate sheet;

[0018] Step 2) Selecting a number of heat dissipation adjustment sheets of appropriate specifications based on the shape of the high-temperature area;

[0019] Step 3) Installing a plurality of heat dissipation adjustment plates into the heat dissipation grooves in sequence;

[0020] Step 4) Place the growth tray into the growth chamber for growth.

[0021] In a feasible embodiment of the diamond growth method, step 1) also includes, under the process conditions of gas pressure 10-15 kPa and growth power 5-10 kW, measuring the high-temperature area on the substrate by infrared rays, the high-temperature area is elliptical in distribution, the long axis of the high-temperature area is 5-12 mm, and the short axis of the high-temperature area is 5-10 mm.

[0022] In a feasible implementation of the diamond growth method, step 2) further includes selecting a plurality of heat dissipation adjustment plates with a long axis of 5 to 12 mm, a short axis of 5 to 10 mm, and a thickness of 1 to 8 mm.

[0023] In a feasible implementation of the diamond growth method, step 3) further includes threading the heat dissipation adjustment plate to the connection column in the heat dissipation groove through the connection through hole on each heat dissipation adjustment plate.

[0024] In a feasible embodiment of the diamond growth method, step 4) further includes evacuating the growth chamber to a vacuum degree of 10 -2 Pa, and then introduce growth gas into the growth chamber until the pressure reaches 10-15kPa, and maintain the growth power at 5-10kW for insulation growth.

[0025] The device for uniform polycrystalline or single crystal diamond growth temperature field and diamond growth method provided by the present invention have the following features:

[0026] Beneficial effects:

[0027] 1. In the present invention, heat dissipation adjustment plates of corresponding shapes and numbers can be installed according to the shape and distribution of the temperature field in the diamond deposition area, so that the thermal conductivity of the inner ring area with higher temperature in the diamond deposition area temperature field is higher, and the thermal conductivity of the outer ring area with lower temperature in the diamond deposition area temperature field is lower, so that the temperature field in the diamond deposition area remains balanced.

[0028] 2. Furthermore, the heat dissipation regulating sheet in the present invention can be processed separately, which greatly reduces the cost. The size and matching of the heat dissipation regulating sheet are adjustable. Special-shaped structures that cannot be completed by normal mechanical processing can be realized by the heat dissipation regulating sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1This is a structural diagram of Example 1 of the present invention.

[0030] Figure 2 Statistical thermal distribution diagram of the temperature field in the diamond deposition area

[0031] Figure 3 This is a structural diagram of Example 2 of the present invention.

[0032] Reference numerals

[0033] Growth support 1

[0034] Substrate 2

[0035] Heat dissipation adjustment sheet 3

[0036] Connecting through hole 31

[0037] Heat dissipation groove 4

[0038] Connecting column 5

[0039] Heat sink 6 DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "left side", "right side", "upper side", "lower side", "above", "below", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0042] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0043] The present invention provides a device for uniform temperature field growth of polycrystalline or single crystal diamond. Referring to Figure 1 or Figure 3 The device comprises a growth tray 1, a substrate sheet 2, and a plurality of stackable heat dissipation adjustment sheets 3. The substrate sheet 2 is placed on top of the growth tray 1 and is used to deposit diamonds. The growth tray 1 is placed on a heat dissipation platform 6 containing a cooling water channel. The heat dissipation platform 6 can cool the heat transferred from the diamonds from top to bottom. The bottom of the growth tray 1 is provided with a heat dissipation groove 4, and the heat dissipation groove 4 is provided with a connecting column 5. The heat dissipation adjustment sheet 3 is provided with a connecting through-hole. The connecting column 5 is detachably connected to the connecting through-hole. Generally speaking, the connecting column 5 and the connecting through-hole are threaded. Current research shows that the temperature field in the diamond deposition area is unbalanced, and the temperature in the center area of ​​the diamond deposition area will be significantly higher than the temperature in the non-center area. Generally, the temperature of the diamond deposition area is uniform by digging grooves on the edge of the growth tray 1. However, the size and depth of the edge grooves need to be continuously adjusted according to different machines and substrate sheets 2. If the grooves are not large or deep enough, the temperature difference between the center area temperature and the non-center area temperature of the diamond deposition area will be large. If the grooves are too large or deep, the overall temperature of the substrate sheet 2 may rise, and the expected process conditions may not be met. The present invention can achieve convenient and rapid heat dissipation adjustment of the temperature field in the diamond deposition area through the heat dissipation regulating sheet 3, as described specifically as follows: the heat dissipation grooves 4 provided in the present invention first make the metal Part of the medium in the heat transfer path from the diamond deposition area to the heat dissipation platform 6 is converted into gas, and then a heat dissipation adjustment plate 3 with a shape matching that of the area is placed on the heat transfer path in the central area where the temperature is higher, so that the medium on the heat transfer path in the central area is all solid (heat transfer path in the central area: growth support 1->several heat dissipation adjustment plates 3->heat dissipation platform 6), while the medium on the heat transfer path in the non-central area is air (heat transfer path in the non-central area: growth support 1->air->heat dissipation platform 6). The thermal conductivity of solid is greater than that of gas, so the heat dissipation in the central area can be faster than that in the non-central area, thereby balancing the temperature field in the diamond deposition area and keeping the temperature uniform between the various areas of the temperature field.

[0044] In a specific embodiment, See Figure 1 or Figure 3 The center point of the heat dissipation groove 4 is located on the central axis of the connecting column 5, and the central axis of the connecting column 5 coincides with the central axis of the growth tray 1.

[0045] In a specific embodiment, the shape of the heat dissipation adjustment plate 3 is selected from any one of a cylinder, an elliptical cylinder or a polygonal cylinder.

[0046] In a specific embodiment, the shape of the heat dissipation adjustment plate 3 is selected from any one of a cylinder, an elliptical cylinder or a polygonal cylinder.

[0047] In a specific embodiment, the heat dissipation regulating plate 3 is an elliptical cylinder, the major axis of the heat dissipation regulating plate 3 is 5-12 mm, the minor axis of the heat dissipation regulating plate 3 is 5-10 mm, and the thickness of the heat dissipation regulating plate 3 is 1-8 mm.

[0048] In a specific embodiment, the growth tray 1 is in the shape of a cylinder or an elliptical cylinder; the heat dissipation groove 4 is in the shape of a cylindrical groove or an elliptical cylinder.

[0049] In a specific embodiment, the growth tray 1 is shaped like a cylinder, the diameter of the growth tray 1 is 110-140 mm, and the height of the growth tray 1 is 9-15 mm; the heat dissipation groove 4 is shaped like a cylindrical groove, the diameter of the heat dissipation groove 4 is 70-100 mm, and the depth of the heat dissipation groove 4 is 1-8 mm.

[0050] In a specific embodiment, the material of the heat dissipation regulating plate 3 is metal or alloy. Specifically, the material of the heat dissipation regulating plate 3 is made of an alloy composed of one or more metal materials selected from molybdenum, titanium, zirconium, tungsten, copper, iron, niobium, and tantalum.

[0051] In a specific embodiment, the material of the growth tray 1 is metal or alloy. Specifically, the material of the growth tray 1 is made of an alloy composed of one or more metal materials selected from molybdenum, titanium, zirconium, tungsten, copper, iron, niobium, and tantalum.

[0052] In a specific embodiment, the material of the substrate sheet 2 is selected from any one of silicon polycrystalline / single crystal, germanium polycrystalline / single crystal, silicon carbide polycrystalline / single crystal, gallium nitride polycrystalline / single crystal, aluminum nitride polycrystalline / single crystal, and diamond polycrystalline / single crystal, or a combination of the above materials, or a coating material.

[0053] The present invention also provides a diamond growth method using the apparatus for uniform polycrystalline or single crystal diamond growth temperature field as described above, comprising the following steps:

[0054] Step 1) Determine the high temperature area on the substrate 2.

[0055] Furthermore, step 1) also includes measuring the high-temperature area on the substrate sheet 2 by infrared rays under the process conditions of air pressure 10-15 kPa and growth power 5-10 kW. The high-temperature area is distributed in an elliptical shape, the long axis of the high-temperature area is 5-12 mm, and the short axis of the high-temperature area is 5-10 mm.

[0056] Step 2) Select a number of heat dissipation adjustment sheets 3 of appropriate specifications according to the shape of the high temperature area.

[0057] Further, step 2) further comprises selecting a plurality of heat dissipation adjusting pieces 3 with a major axis of 5-12mm, a minor axis of 5-10mm, and a thickness of 1-8mm.

[0058] Step 3) installing a plurality of heat dissipation adjusting pieces 3 into the heat dissipation groove 4.

[0059] Further, step 3) further comprises screwing the heat dissipation adjusting piece 3 with the connecting column 5 in the heat dissipation groove 4 through the connecting through hole on the heat dissipation adjusting piece 3.

[0060] Step 4) placing the growth holder 1 into the growth chamber for growth.

[0061] Further, step 4) further comprises vacuumizing the growth chamber to a vacuum degree of 10 -2 Pa, and then introducing growth gas into the growth chamber to a gas pressure of 10-15kPa and a growth power of 5-10kW.

[0062] Example One

[0063] In this example, a 2-inch substrate piece 2 is used for deposition, and a general growth holder 1 can be used for the growth holder 1, which has a diameter of 130mm and a height of 14mm, wherein the diameter of the heat dissipation groove 4 is 80mm, and the depth of the heat dissipation groove 4 is 7mm.

[0064] Step 1) determining the high-temperature area on the substrate piece 2.

[0065] Further, under the conditions of a gas pressure of 14kPa and a growth power of 6kW, the different areas of the substrate piece 2 are measured by infrared to obtain an elliptical high-temperature area with a major axis of 10mm and a minor axis of 8mm, as shown in Figure 2 .

[0066] Step 2) selecting a plurality of heat dissipation adjusting pieces 3 with appropriate specifications according to the shape of the high-temperature area.

[0067] Further, an elliptical heat dissipation adjusting piece 3 with a major axis of 10mm, a minor axis of 8mm, and a thickness of 7mm is selected.

[0068] Step 3) installing a plurality of heat dissipation adjusting pieces 3 into the heat dissipation groove 4;

[0069] Further, the connecting through hole in the heat dissipation adjusting piece 3 is aligned with the connecting column 5, and then the heat dissipation adjusting piece 3 is connected with the connecting column 5 through screwing.

[0070] Step 4) placing the growth holder 1 into the growth chamber for growth.

[0071] Further, the growth chamber is vacuumized to a vacuum degree of 10 -2Pa, then introduce growth gas into the growth chamber until the pressure reaches 14kPa, and maintain the growth power at 6kW for insulation growth. The comparative data are shown in Table 1 below:

[0072] surface 1 1

[0073]

[0074]

[0075] Data shows that after adjusting the temperature field in the diamond growth area using this embodiment, the thickness difference of diamond deposition at each position is only 0.07 mm, and the thickness non-uniformity is only 8.6%, which is an improvement of nearly 40% compared to the mode without using this embodiment for adjustment.

[0076] Example 2

[0077] In this embodiment, a 3-inch substrate sheet 2 is used for deposition, and the growth tray 1 can adopt a universal growth tray 1, the universal growth tray 1 has a diameter of 130 mm and a height of 14 mm, wherein the diameter of the heat dissipation groove 4 is 80 mm and the depth of the heat dissipation groove 4 is 6 mm.

[0078] Step 1) Determine the high temperature area on the substrate 2.

[0079] Furthermore, under the conditions of gas pressure of 13 kPa and growth power of 7 kW, infrared measurement of different areas of the substrate sheet 2 revealed an elliptical high-temperature area with a long axis of 8 mm and a short axis of 6 mm and a circular high-temperature area with a diameter of 15 mm, and the center points of the two high-temperature areas coincided.

[0080] Step 2) Select a number of heat dissipation adjustment sheets 3 of appropriate specifications according to the shape of the high temperature area.

[0081] Furthermore, an elliptical heat dissipation adjustment sheet 3 with a major axis of 8 mm, a minor axis of 6 mm, and a thickness of 3 mm and a circular heat dissipation adjustment sheet 3 with a diameter of 15 mm and a thickness of 3 mm are selected.

[0082] Step 3) Installing a plurality of heat dissipation adjustment sheets 3 into the heat dissipation grooves 4 in sequence;

[0083] Furthermore, the connecting through hole in the elliptical heat dissipation adjusting plate 3 is aligned with the connecting column 5, and then the elliptical heat dissipation adjusting plate 3 and the connecting column 5 are connected by threads; then, the connecting through hole in the circular heat dissipation adjusting plate 3 is aligned with the connecting column 5, and then the circular heat dissipation adjusting plate 3 and the connecting column 5 are connected by threads.

[0084] Step 4) Place the growth tray 1 into the growth chamber for growth.

[0085] Furthermore, the growth chamber was evacuated to a vacuum degree of 10 -2 Pa, and then introduce growth gas into the growth chamber until the pressure reaches 13kPa, and maintain the growth power at 6kW for insulation growth.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A device for uniform temperature field for growing polycrystalline or single crystal diamond, characterized by: The invention comprises a growth support (1), a substrate sheet (2), and a plurality of heat dissipation adjustment sheets (3) that can be stacked in sequence. The substrate sheet (2) is arranged on the top of the growth support (1) and is used for depositing diamonds. The growth support (1) is used for being placed on a heat dissipation platform containing a cooling water channel. A heat dissipation groove (4) is provided at the bottom of the growth support (1), and a connecting column (5) is provided in the heat dissipation groove (4). A connecting through hole is provided in the heat dissipation regulating sheet (3), the connecting column (5) is detachably connected to the connecting through hole, and a plurality of heat dissipation regulating sheets (3) can be stacked in sequence in the heat dissipation groove (4).

2. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 1, characterized in that: The center point of the heat dissipation groove (4) is located on the center axis of the connecting column (5), and the center axis of the connecting column (5) coincides with the center axis of the growth support (1).

3. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 1, characterized in that: The shape of the heat dissipation regulating plate (3) is selected from any one of a cylinder, an elliptical cylinder or a polygonal cylinder.

4. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 3, characterized in that: The heat dissipation regulating plate (3) is an elliptical cylinder, the major axis of the heat dissipation regulating plate (3) is 5 to 12 mm, the minor axis of the heat dissipation regulating plate (3) is 5 to 10 mm, and the thickness of the heat dissipation regulating plate (3) is 1 to 8 mm.

5. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 1, characterized in that: The growth support (1) is in the shape of a cylinder or an elliptical cylinder; the heat dissipation groove (4) is in the shape of a cylindrical groove or an elliptical cylinder.

6. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 5, characterized in that: The growth tray (1) is in the shape of a cylinder, the diameter of the growth tray (1) is 110-140 mm, and the height of the growth tray (1) is 9-15 mm; the heat dissipation groove (4) is in the shape of a cylindrical groove, the diameter of the heat dissipation groove (4) is 70-100 mm, and the depth of the heat dissipation groove (4) is 1-8 mm.

7. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 1, characterized in that: The material of the heat dissipation regulating plate (3) is metal or alloy; and / or the material of the growth support (1) is metal or alloy.

8. The device for uniform polycrystalline or single crystal diamond growth temperature field according to claim 1, characterized in that: The material of the substrate sheet (2) is selected from any one of silicon polycrystalline / single crystal, germanium polycrystalline / single crystal, silicon carbide polycrystalline / single crystal, gallium nitride polycrystalline / single crystal, aluminum nitride polycrystalline / single crystal, and diamond polycrystalline / single crystal, or is a combination of the above materials, or is a coating material.

9. A diamond growth method using the apparatus for uniform polycrystalline or single crystal diamond growth temperature field according to any one of claims 1 to 8, comprising the following steps: Step 1) determining a high temperature area on the substrate sheet (2); Step 2) Selecting a number of heat dissipation adjustment sheets (3) of appropriate specifications according to the shape of the high temperature area; Step 3) installing a plurality of heat dissipation adjustment sheets (3) into the heat dissipation groove (4); Step 4) Place the growth tray (1) into the growth chamber for growth.

10. The diamond growth method according to claim 9, wherein: Including any of the following technical features: Step 1) further comprises, under process conditions of a gas pressure of 10 to 15 kPa and a growth power of 5 to 10 kW, measuring a high temperature area on the substrate (2) by infrared light, wherein the high temperature area is elliptical in shape, the long axis of the high temperature area is 5 to 12 mm, and the short axis of the high temperature area is 5 to 10 mm; Step 2) further includes selecting a plurality of heat dissipation adjustment sheets (3) with a long axis of 5 to 12 mm, a short axis of 5 to 10 mm, and a thickness of 1 to 8 mm; Step 3) further includes threading the heat dissipation adjustment plate (3) to the connection column (5) in the heat dissipation groove (4) through the connection through hole on each heat dissipation adjustment plate (3); Step 4) also includes evacuating the growth chamber to a vacuum degree of 10 -2 Pa, and then introduce growth gas into the growth chamber until the pressure reaches 10-15kPa, and maintain the growth power at 5-10kW for insulation growth.

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