Molybdenum table

Abstract

The utility model belongs to the field of diamond film preparation, and discloses a molybdenum table. The molybdenum table comprises a base, a circular groove is formed in the upper surface of the base, and a growth cylinder is arranged at the bottom of the circular groove; the growth cylinder comprises a cylinder section and a convex spherical surface located on the upper portion of the cylinder section, the height of the cylinder section is smaller than the depth of the circular groove, and the height of the growth cylinder is larger than the depth of the circular groove. The molybdenum table provided by the utility model is simple in structure, and the edge effect of the vibrating diaphragm can be slowed down through the structural limitation and further size setting of the base, the circular groove and the growing cylinder, so that the thickness of the vibrating diaphragm is uniform.

Description

Technical Field

[0001] This utility model belongs to the field of diamond film preparation, and relates to a molybdenum stage, and more specifically, to a molybdenum stage for preparing diamond diaphragms. Background Technology

[0002] Chemical vapor deposition (CVD) is an effective method for preparing high-quality diamond diaphragms. In particular, microwave chemical vapor deposition (MPCVD) has become the preferred method for preparing high-quality diamond diaphragms due to its advantages such as high plasma density and no electrode contamination. However, preparing high-quality diamond diaphragms is not easy, and its quality is affected by a variety of factors. In particular, the growth of the transition layer directly determines whether the diamond diaphragm can be completely demolded.

[0003] In the existing technology for preparing diamond diaphragms, silicon wafers are often used as growth substrates. After growth, the silicon wafers are dissolved with acid or alkali to obtain the final diamond diaphragm. This has the following problems: (1) Using silicon wafers as growth substrates makes the ultra-precision processing of silicon difficult and the processing cost is high; (2) Silicon wafers cannot be reused, resulting in waste and high production costs; (3) There is an edge effect during the growth of diamond diaphragms, which makes the grown diamond diaphragms thicker at the edges and thinner in the center. During the substrate cooling process, the diamond diaphragms are prone to cracking or even cannot be demolded. Utility Model Content

[0004] The purpose of this invention is to provide a molybdenum stage for preparing diamond diaphragms, so as to solve at least one technical problem existing in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A molybdenum stage includes a base, a circular groove is provided on the upper surface of the base, and a growth cylinder is provided at the bottom of the circular groove;

[0007] The growth cylinder includes a cylindrical segment and a convex spherical surface located on the upper part of the cylindrical segment. The height of the cylindrical segment is less than the depth of the circular groove, and the height of the growth cylinder is greater than the depth of the circular groove.

[0008] Furthermore, the upper surface of the base and the side surface of the base are connected by an inward concave arc to form an annular arc transition surface.

[0009] Furthermore, the diameter of the arc transition surface decreases from bottom to top.

[0010] Furthermore, the bottom of the circular groove is a horizontal plane, and the growth cylinder is vertically arranged at the bottom of the circular groove.

[0011] Furthermore, at least three growth cylinders are provided.

[0012] Furthermore, the plurality of growth cylinders are evenly distributed at the bottom of the circular groove.

[0013] More preferably, the plurality of growth cylinders are arranged in a circumferential array and evenly distributed at the bottom of the circular groove.

[0014] Furthermore, the base is a cylindrical structure or a frustum-shaped structure.

[0015] Furthermore, the central axis of the circular groove coincides with the central axis of the base.

[0016] Furthermore, the diameter D of the base is ≤72mm, and the height h1 of the base is 15mm ≤20mm.

[0017] Furthermore, the diameter of the circular groove is ≤60mm, and the depth h2 of the circular groove is ≤5mm (3mm≤).

[0018] Furthermore, 10mm < the diameter d of the cylindrical segment of the growing cylinder < 25mm; the height h3 of the cylindrical segment of the growing cylinder = the depth h2 - 1mm of the circular groove.

[0019] Furthermore, the diameter of the convex spherical surface at the top of the growth cylinder is 20~40mm; the sag h3≤3mm, and the roughness Ra≤1.6μm. It should be noted that the sag of the convex spherical surface refers to the maximum thickness of the convex spherical surface in the vertical direction.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] (1) The molybdenum stage of this utility model has a simple structure. Through the structural constraints of the base, circular groove, and growth cylinder, as well as further size settings, the edge effect of the diaphragm can be reduced, and the thickness of the diaphragm can be made more uniform.

[0022] (2) The molybdenum stage structure of this utility model can be set with multiple growth cylinders, thereby realizing the mass growth of diamond diaphragms.

[0023] (3) Reduce production costs, ensure a safe production environment to a certain extent, and reduce environmental pollution; effectively improve product yield and shorten the growth cycle of diamond diaphragms. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 This is a three-dimensional structural diagram of the molybdenum stage in Example 1;

[0026] Figure 2This is a top view of the molybdenum stage in Example 1;

[0027] Figure 3 This is a schematic cross-sectional view of the molybdenum stage in Example 1;

[0028] Figure 4 This is a process flow diagram from Example 2;

[0029] Figure 5 This is a three-dimensional structural diagram of the molybdenum stage in Comparative Example 1;

[0030] Figure 6 This is a top view of the molybdenum stage in Comparative Example 1.

[0031] Wherein: 1—base, 2—upper surface of base, 3—circular groove, 4—growing cylinder, 5—concave arc, 6—convex spherical surface. Detailed Implementation

[0032] To facilitate understanding of this utility model, it will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this invention.

[0034] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0035] Example 1

[0036] like Figures 1-3 As shown, this embodiment provides a molybdenum stage for preparing diamond diaphragms, including a cylindrical base 1, a circular groove 3 on the upper surface 2 of the base, a growth cylinder 4 at the bottom of the circular groove 3, and a convex spherical surface 6 at the top of the growth cylinder 4.

[0037] In this embodiment, the growth cylinder 4 is divided into a cylindrical section at the bottom and a convex spherical surface 6 at the top. The height of the cylindrical section is less than the depth of the circular groove 3, and the height of the growth cylinder 4 is greater than the depth of the circular groove 3.

[0038] In this embodiment, the upper surface 2 of the base and the side surface of the base are transitioned by an inward concave arc 5 to form an arc transition surface. As a further preferred embodiment, the diameter of the arc transition surface gradually decreases from bottom to top.

[0039] In this embodiment, the central axis of the circular groove 3 coincides with the central axis of the base 1.

[0040] In this embodiment, the bottom of the circular groove 3 is a horizontal plane, and the growth cylinder 4 is vertically arranged at the bottom of the circular groove 3.

[0041] In this embodiment, three growth cylinders 4 are provided, and the three growth cylinders 4 are evenly distributed in a circumferential array at the bottom of the circular groove 3.

[0042] In this embodiment:

[0043] The diameter of the base 1 is D = 72 mm, and h1 = 20 mm.

[0044] The diameter of the circular groove 3 is 60mm, and the depth of the circular groove 3 is h2 = 5mm.

[0045] The diameter of the cylindrical segment of the growing cylinder 4 is d = 25 mm, and the height of the cylindrical segment of the growing cylinder 4 is h3 = 4 mm.

[0046] The diameter of the convex spherical surface 6 at the top of the growth cylinder 4 is 25 mm; the sagitta h3 ≤ 3 mm, and the roughness Ra ≤ 1.6 μm.

[0047] Example 2

[0048] This embodiment provides a method for preparing a polycrystalline diamond diaphragm, using the molybdenum stage from Example 1, such as... Figure 4 As shown, it includes the following steps:

[0049] (1) Clean the molybdenum stage by ultrasonically cleaning it with acetone, alcohol and deionized water in sequence, and then drying it.

[0050] (2) Apply the release agent to the upper surface of the molybdenum platform and dry it;

[0051] (3) Place the dried molybdenum stage into the deposition chamber of the MPCVD equipment for diamond film deposition;

[0052] (4) After deposition is complete, cool down and remove the film;

[0053] The release agent is a graphite emulsion aqueous solution, in which the volume ratio of graphite emulsion to water is 1:3, and the coating thickness is 10 micrometers.

[0054] In step (2) of this embodiment, the coating method is: spraying with a spray gun. In this embodiment, spraying with a spray gun allows the graphite emulsion to be more evenly adsorbed onto the molybdenum platform.

[0055] In step (1) of this embodiment, the drying temperature is 100°C. In this embodiment, the coated molybdenum platform needs to be dried. If there is too much moisture, it will cause unevenness of the sprayed surface during the transfer of the molybdenum platform.

[0056] In step (3) of this embodiment, during the diamond diaphragm deposition process, 400 sccm of hydrogen and 12 sccm of methane are introduced.

[0057] In this embodiment, nitrogen, oxygen, and argon are also introduced, with a volume ratio of V to hydrogen of V0. 氮气 / V 氢气 =0.1%, V 氧气 / V 氢气 =0.1%, V 氩气 / V 氢气 =0.1%.

[0058] In this embodiment, the pressure inside the deposition chamber is maintained at 15 kPa.

[0059] In this embodiment, the growth temperature inside the deposition chamber is maintained at 600°C.

[0060] In this embodiment, the deposition time is 24 hours.

[0061] In step (4) of this embodiment, the cooling rate during the cooling and demolding process is 10℃ / min.

[0062] The diamond diaphragm obtained in this embodiment can detach naturally on the molybdenum stage.

[0063] Comparative Example 1

[0064] This comparative example is basically the same as Example 2, except that the growth stage of molybdenum in this comparative example does not have a circular groove.

[0065] like Figure 5 and 6 As shown in the comparative example, a molybdenum stage is provided, including a cylindrical base, with a growth cylinder on the top of the base, the top of which is a convex spherical surface.

[0066] In this comparative example, the growth cylinder is divided into a cylindrical section at the bottom and a convex spherical surface at the top.

[0067] In this comparative example, the upper surface of the base and the side surface of the base are connected by an inward concave arc to form an arc transition surface. As a further preferred embodiment, the diameter of the arc transition surface gradually decreases from bottom to top.

[0068] In this comparative example, the top of the base is a horizontal plane, and the growth cylinder is vertically arranged on the top of the base.

[0069] In this comparative example, three growth cylinders are provided, and the three growth cylinders are evenly distributed in a circumferential array on the top of the base.

[0070] In this comparative example:

[0071] The base has a diameter D = 72 mm and an h1 = 20 mm.

[0072] The diameter of the cylindrical section of the growing cylinder is d = 25 mm, and the height of the cylindrical section of the growing cylinder is h3 = 4 mm.

[0073] The diameter of the convex spherical surface at the top of the growth cylinder is 25 mm; the sagitta h3 ≤ 3, and the roughness Ra ≤ 1.6 μm.

[0074] Table 1

[0075]

[0076] Table 1 shows the experimental parameters and diaphragm growth rate during the experiments for Example 2 and Comparative Example 1.

[0077] As can be seen from Comparative Example 1 and Example 2, the edge structure can significantly reduce the edge effect, promote the uniform distribution of plasma on the molybdenum stage, and result in a uniform diaphragm thickness and high product performance.

[0078] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the scope of this utility model.

Claims

1. A molybdenum stage, characterized in that, Includes a base, with a circular groove on the upper surface of the base, and a growth cylinder at the bottom of the circular groove; The growth cylinder includes a cylindrical segment and a convex spherical surface located on the upper part of the cylindrical segment. The height of the cylindrical segment is less than the depth of the circular groove, and the height of the growth cylinder is greater than the depth of the circular groove.

2. The molybdenum stage as described in claim 1, characterized in that, The upper surface of the base and the side surface of the base are connected by an inward concave arc to form an annular arc transition surface.

3. The molybdenum stage as described in claim 2, characterized in that, The diameter of the arc transition surface decreases from bottom to top.

4. The molybdenum stage as described in claim 1, characterized in that, The bottom of the circular groove is horizontal, and the growth cylinder is vertically positioned at the bottom of the circular groove.

5. The molybdenum stage as described in claim 1, characterized in that, Multiple growth cylinders are evenly distributed at the bottom of the circular groove.

6. The molybdenum stage as described in claim 1, characterized in that, The base is a cylindrical or frustum-shaped structure; the central axis of the circular groove coincides with the central axis of the base.

7. The molybdenum stage as described in claim 1 or 6, characterized in that, The diameter D of the base is ≤72mm; the height h1 of the base is ≤20mm and 15mm.

8. The molybdenum stage as described in claim 1, characterized in that, The diameter of the circular groove is ≤60mm; the depth of the circular groove is ≤3mm and h2 is ≤5mm.

9. The molybdenum stage as described in claim 1 or 8, characterized in that, 10mm < diameter d of the cylindrical section of the growing cylinder < 25mm; height h3 of the cylindrical section of the growing cylinder = depth h2 - 1mm of the circular groove.

10. The molybdenum stage as described in claim 1, characterized in that, The diameter of the convex spherical surface at the top of the growth cylinder is 20~40mm; the sagitta h3≤3mm; and the roughness Ra≤1.6μm.

Images