A substrate table system and an MPCVD apparatus

Abstract

The application provides a substrate table system MPCVD device, comprising: a microwave reflection table and a large molybdenum table which are arranged in a stack; a substrate table which is arranged on a side of the large molybdenum table away from the microwave reflection table; wherein the side of the large molybdenum table away from the microwave reflection table is provided with an annular protrusion which is coaxial with the substrate table and surrounds an outer periphery of the substrate table. In this way, the annular protrusion arranged on the outer periphery of the substrate table can make the plasma formed above the substrate table more uniformly distributed, thereby reducing the temperature difference between the center and the edge, ensuring the uniformity of the diamond growth rate, reducing the stress of the diamond crystal, and reducing the rate of splitting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, in particular to a substrate table system and an MPCVD device. BACKGROUND

[0002] With the expansion of the use of the third generation semiconductor material, diamond, as the ultimate semiconductor material, has a wide application prospect in many fields due to its characteristics such as large band gap, high thermal conductivity, and high breakdown field strength.

[0003] Large-size diamond is mainly grown by using the MPCVD (Microwave plasma chemical vapor deposition) method. In the growth of diamond, H2 and CH4 are used as the main reaction gases, the reaction gases are introduced into the resonant reaction cavity of the MPCVD device, and at the same time, microwaves are fed in. The microwaves generate a strong electric field above the substrate table in the resonant reaction cavity. The strong electric field ionizes the reaction gases to form carbon-containing plasma groups. When the substrate meets the growth temperature interval of 800-1200℃, the plasma groups diffuse to the surface of the substrate and deposit diamond on the surface of the substrate.

[0004] In the growth of diamond, the plasma is both a reaction source and a heat source. However, the density distribution of the plasma is often uneven, which causes the uneven distribution of the substrate temperature. When growing large-area diamond, the temperature difference between the center and the edge of the substrate is large (the temperature difference within 20mm distance between the center and the edge of the substrate holder is 160K), which leads to the inconsistent growth rate, large thickness difference, and large stress between the center and the edge of the large-area diamond after the growth is completed, resulting in the bending and even cracking of the diamond. SUMMARY

[0005] Therefore, the present application provides a substrate table system and an MPCVD device, which can balance the radial temperature gradient on the upper surface of the substrate table, ensure the consistent growth rate of diamond, reduce the stress of diamond crystal, and reduce the cracking rate.

[0006] In order to achieve the above purpose, the present application provides the following technical solutions:

[0007] A substrate table system comprises:

[0008] A microwave reflection table and a large molybdenum table are arranged in layers.

[0009] A substrate table is arranged on the side of the large molybdenum table away from the microwave reflection table.

[0010] The side of the large molybdenum table away from the microwave reflection table is provided with an annular protrusion, the annular protrusion is coaxial with the substrate table, and surrounds the outer periphery of the substrate table.

[0011] Optionally, the annular protrusion is arranged spaced apart from the substrate table;

[0012] Optionally, a surface of the annular protrusion away from the molybdenum table is lower than a surface of the substrate table away from the molybdenum table.

[0013] Optionally, a side of the annular protrusion close to the substrate table is perpendicular to a side of the molybdenum table away from the microwave reflection table, and a side of the annular protrusion away from the substrate table is arranged as a curved surface.

[0014] Optionally, a side of the molybdenum table away from the microwave reflection table is provided with a retainer, the retainer is arranged around an outer periphery of the substrate table to position the substrate table, and the annular protrusion is arranged around the retainer.

[0015] Optionally, an outer periphery of the substrate table is in contact with the retainer through a first contact structure, and the first contact structure is arranged as a line contact structure or a point contact structure.

[0016] Optionally, the first contact structure comprises a plurality of first pointed protrusions arranged on an inner side of the retainer, the plurality of first pointed protrusions are distributed along a circumferential direction of the substrate table, and a pointed portion of the first pointed protrusion is in abutment with the outer periphery of the substrate table.

[0017] Optionally, the molybdenum table is arranged as an annular shape, and a side of the substrate table facing the molybdenum table is in abutment with the molybdenum table.

[0018] Optionally, a side of the substrate table facing the molybdenum table is provided with a second contact structure, and the substrate table is in contact with the molybdenum table through the second contact structure, and the second contact structure is arranged as a line contact structure or a point contact structure.

[0019] Optionally, the second contact structure comprises a second pointed protrusion arranged on the side of the substrate table facing the molybdenum table and located at an edge of the substrate table, and a pointed portion of the second pointed protrusion is in abutment with a side of the molybdenum table.

[0020] Optionally, a side of the microwave reflection table close to the molybdenum table is provided with a first positioning protrusion, the first positioning protrusion is arranged around an outer periphery of the molybdenum table and can position the molybdenum table;

[0021] A side of the microwave reflection table away from the molybdenum table is provided with a metal table, and a side of the microwave reflection table away from the molybdenum table is provided with a second positioning protrusion, the second positioning protrusion is arranged around an outer periphery of the metal table and can position the metal table.

[0022] Optionally, further comprising: a heat dissipation table;

[0023] The large molybdenum platform and the microwave reflection platform are both annular and surround the outer periphery of the heat dissipation platform, and there is a gap between the substrate platform and the heat dissipation platform so that the heat dissipation platform can radiate heat to the substrate platform.

[0024] The side of the heat dissipation platform close to the substrate platform is sequentially formed with a plurality of heat dissipation portions from the middle to the edge, and the heat dissipation coefficient of the heat dissipation portions located at the middle and the edge of the heat dissipation platform is greater than that of the heat dissipation portions located between the middle and the edge of the heat dissipation platform, so as to compensate the temperature of the substrate platform through non-uniform heat dissipation.

[0025] Optionally, the plurality of heat dissipation portions are made of the same material, and the surface roughness of the heat dissipation portions located at the middle and the edge of the heat dissipation platform is greater than that of the heat dissipation portions located between the middle and the edge of the heat dissipation platform.

[0026] Optionally, the plurality of heat dissipation portions are made of different materials, and the surface emissivity of the heat dissipation portions located at the middle and the edge of the heat dissipation platform is greater than that of the heat dissipation portions located between the middle and the edge of the heat dissipation platform.

[0027] Optionally, the side of the heat dissipation platform close to the substrate platform is provided with a radiation heat dissipation layer, and the radius of the radiation heat dissipation layer is less than that of the heat dissipation platform, so as to sequentially form the plurality of heat dissipation portions at the radiation heat dissipation layer and the edge of the heat dissipation platform.

[0028] Optionally, the plurality of heat dissipation portions are all made of oxygen-free copper material, the surface roughness of the middle of the radiation heat dissipation layer is set to 1.6-3.2 microns, the surface roughness of the edge of the radiation heat dissipation layer is set to 0.3-1.2 microns, and the roughness of the edge of the heat dissipation platform is set to 0.1-0.6 microns.

[0029] Optionally, the system further comprises:

[0030] A lifting assembly connected to the heat dissipation platform, the lifting assembly being used to drive the heat dissipation platform to approach or move away from the substrate platform along the axial direction.

[0031] An MPCVD device comprising a reaction chamber and a substrate platform system as claimed in any one of the preceding claims arranged in the reaction chamber.

[0032] The substrate table system MPCVD device provided in the application is provided with an annular protrusion on the side of the large molybdenum table away from the microwave reflection table (i.e. the upper surface of the large molybdenum table), which surrounds the outside of the substrate table. During the growth of diamond, the electric field in the reaction chamber is 2.45 GHz, and a strong electric field area can be formed above the large molybdenum table by the setting of the microwave emission table, so as to realize microwave plasma discharge. Since the annular protrusion surrounds the outside of the substrate table, the position of the annular protrusion can slightly induce edge discharge, guiding the edge discharge originally on the substrate table to the annular protrusion. Although the annular protrusion weakens the absolute electric field size above the substrate table as a whole, the electric field uniformity can be improved from 15% to 8% by the annular protrusion structure, and the plasma shape can be made flat and the heat source can be made relatively uniform. In this way, the annular protrusion is arranged on the periphery of the substrate table, so that the plasma formed above the substrate table is more uniformly distributed, thereby reducing the temperature difference between the center and the edge, ensuring the consistency of the diamond growth rate, reducing the stress of the diamond crystal, and reducing the crack rate. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0034] Figure 1 Partial cross-sectional view of the substrate table system shown in some embodiments;

[0035] Figure 2 Partial enlarged view in Figure 1

[0036] Figure 3 Partial exploded view of the support assembly shown in some embodiments;

[0037] Figure 4 Perspective view of the retainer shown in some embodiments;

[0038] Figure 5 Cross-sectional view of the substrate table shown in some embodiments;

[0039] Figure 6 Cross-sectional view of the heat dissipation table shown in some embodiments;

[0040] Figure 7 Upper perspective cross-sectional view of the substrate table system shown in some embodiments;

[0041] Figure 8 ​A lower perspective sectional view of a substrate table system shown in some embodiments;

[0042] Figure 9 A structural diagram of an MPCVD apparatus shown in some embodiments;

[0043] Figure 10 An electric field simulation diagram without annular protrusions;

[0044] Figure 11 An electric field simulation diagram with annular protrusions;

[0045] Figure 12 A comparison diagram of electric field simulation results shown in some embodiments.

[0046] In the figure: 1, substrate table system; 2, plasma; 3, reaction chamber; 4, quartz dielectric window; 5, mode conversion cavity; 6, antenna; 7, mode converter; 8, three pins; 9, microwave generator; 11, metal table; 12, microwave reflection table; 13, large molybdenum table; 14, retainer; 15, substrate table; 16, radiation heat dissipation layer; 17, first heat dissipation channel; 18, heat dissipation table; 19, inner heat dissipation column; 20, outer heat dissipation column; 21, first flexible pipe; 22, second flexible pipe; 23, flange; 131, annular protrusion; 141, first pointed protrusion; 151, second pointed protrusion; 161, first heat dissipation part; 162, second heat dissipation part; 163, third heat dissipation part; 191, inlet of first heat dissipation channel; 192, outlet of first heat dissipation channel; 201, inlet of second heat dissipation channel. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0048] As Figures 1-12 shown, the present application provides a substrate table system arranged in a reaction chamber 3 for growing diamond, comprising a substrate table 15 and a support assembly. The substrate table 15 is a placing table for diamond substrate, used for carrying the growth of diamond. The support assembly is used to support the substrate table 15 to realize the fixation of the substrate table 15.

[0049] In a specific scheme, as Figures 1-3As shown, the support assembly comprises a metal base 11 (preferably made of a metal material with good thermal conductivity such as copper), a microwave emission base 12, a large molybdenum base 13, and a retainer 14 (preferably made of a high-temperature-resistant material), the metal base 11, the microwave emission base 12, and the large molybdenum base 13 are sequentially stacked from bottom to top, i.e., the microwave emission base 12 is arranged between the metal base 11 and the large molybdenum base 13.

[0050] The large molybdenum base 13 is provided with an annular protrusion 131 on the side away from the microwave reflection base 12 (i.e., the upper surface of the large molybdenum base 13), and the annular protrusion 131 surrounds the outside of the substrate base 15. During the growth of the diamond, the electric field in the reaction chamber 3 is at 2.45 GHz, and by arranging the microwave emission base 12, a strong electric field region can be formed above the large molybdenum base 13 to realize microwave plasma discharge. Since the annular protrusion 131 surrounds the outside of the substrate base 15, the position of the annular protrusion 131 can slightly induce edge discharge, guiding the edge discharge originally on the substrate base 15 to the annular protrusion 131. Although the annular protrusion 131 weakens the absolute electric field above the substrate base 15 in the overall situation, the electric field uniformity (the electric field uniformity = (electric field maximum value - electric field minimum value) / electric field maximum value, here the smaller the uniformity, the more uniform the electric field) can be improved from 15% to 8% through the structure of the annular protrusion 131, and the plasma shape can be made flatter and the heat source can be made relatively uniform.

[0051] In this way, by arranging the annular protrusion 131 on the outer periphery of the substrate base 15, the plasma formed above the substrate base 15 can be more uniformly distributed, thereby reducing the temperature difference between the center and the edge, ensuring consistent diamond growth rate, reducing diamond crystal stress, and reducing the rate of splitting.

[0052] Further, the annular protrusion 131 is not in contact with the edge of the substrate table 15 (i.e. the annular protrusion 131 is spaced apart from the substrate table 15), and / or the surface of the annular protrusion 131 away from the molybdenum table 13 is lower than the surface of the substrate table 15 away from the molybdenum table 13, i.e. the height of the upper surface of the annular protrusion 131 is lower than the height of the upper surface of the substrate table 15, for example, the height of the annular protrusion 131 protruding from the molybdenum table 13 is set to 3-5 mm, so that even if the annular protrusion 131 is slightly discharged, the temperature uniformity of the substrate table 15 will not be deteriorated, and the polycrystalline at the edge of the substrate table 15 can be controlled to be always lower than the growth rate of the single crystal diamond seed (the single crystal diamond seed with a thickness of 0.2 mm is placed on the top surface of the substrate table 15) placed on the substrate, effectively preventing the polycrystalline from affecting the deposition of the single crystal (during the growth process, polycrystalline diamond as a byproduct of the process will be deposited at the annular protrusion 131, if the position of the annular protrusion 131 is higher than the top surface of the substrate table 15, the tip discharge at the annular protrusion 131 will be stronger, and the growth rate of the polycrystalline diamond at the annular protrusion 131 will be faster, and after a long time of growth, the thickening of the polycrystalline growth will affect the growth of the single crystal on the upper surface of the substrate table 15).

[0053] In the present embodiment, the radius of the annular protrusion 131 is set to 26-35 mm, i.e. the distance from the annular protrusion 131 to the central axis of the reaction chamber 3 is 26-35 mm, since the diamond growth generally uses a microwave of 2.45 GHz, the wavelength of the microwave is 122 mm, and the diameter of the molybdenum table 13 is 90-110 mm, the annular protrusion 131 can focus the electric field to half the wavelength, i.e. to the substrate table 15, so that the electric field at the edge of the substrate table 15 is more uniform than without the annular protrusion 131, further flattening the plasma.

[0054] In the present embodiment, the side of the annular protrusion 131 close to the substrate table 15 (i.e. the inner circumferential surface of the annular protrusion 131) is set to a vertical shape, i.e. the inner circumferential surface of the annular protrusion 131 is perpendicular to the upper surface of the molybdenum table 13, and the side of the annular protrusion 131 away from the substrate table (i.e. the outer circumferential surface of the annular protrusion 131) is set to an arc surface shape, so that the outer edge of the annular protrusion 131 can be prevented from forming a sharp tip discharge.

[0055] In some preferred embodiments, the side of the molybdenum table 13 away from the microwave reflection table 12 (i.e. the upper surface of the molybdenum table 13) is provided with a holder 14, and the holder 14 is arranged around the outer periphery of the substrate table 15 to position the substrate table 15, and the annular protrusion 131 is arranged around the outer periphery of the holder 14 to position the holder, for example, the inner circumferential surface of the annular protrusion 131 is in clearance fit with the outer circumferential surface of the holder 14. In this way, the position of the holder 14 between the annular protrusion 131 and the substrate table 15 can be limited in the radial direction, which is conducive to ensuring the accurate and stable position of the holder 14 relative to the molybdenum table 13.

[0056] The outer circumferential surface of the substrate table 15 is in contact with the holder 14 through a first contact structure, which is provided as a line contact structure or a point contact structure. In this way, the contact area between the substrate table 15 and the holder 14 can be reduced, and the heat conduction caused by the contact can be reduced, which is conducive to ensuring the temperature stability of the heat dissipation table 18.

[0057] As shown in Figure 4 The first contact structure includes a plurality of first pointed protrusions 141, which are arranged on the inner side (the side close to the substrate table 15) of the holder 14 and are distributed in a circumferential direction of the substrate table 15. The pointed portions of the plurality of first pointed protrusions 141 are in abutment with the substrate table 15, thereby achieving radial limiting of the substrate table 15. For example, the first pointed protrusions 141 are provided as triangular protruding ridges. The size of the first pointed protrusions 141 gradually decreases in a direction close to the substrate table 15. The ridges of the first pointed protrusions 141 are in line contact with the substrate table 15, and the contact area is small, which is conducive to reducing heat conduction.

[0058] In some preferred embodiments, the large molybdenum table 13 is provided in a ring shape. The side of the substrate table 15 facing the large molybdenum table 13 is in abutment with the large molybdenum table 13, thereby achieving support of the substrate table 15 by the large molybdenum table 13. Specifically, the entire support assembly can be provided in a ring shape. The edge of the large molybdenum table 13 is in abutment with the substrate table 15, thereby achieving support of the substrate table 15. In this way, the contact area between the large molybdenum table 13 and the substrate table 15 is small, which is conducive to reducing heat conduction caused by contact and the influence of the temperature of the substrate table 15.

[0059] Further, the side (i.e., the lower surface) of the substrate table 15 facing the large molybdenum table 13 is provided with a second contact structure. The substrate table 15 is in contact with the large molybdenum table 13 through the second contact structure. The second contact structure is provided as a line contact structure or a point contact structure. In this way, the contact area between the substrate table 15 and the large molybdenum table 13 can be reduced, and the heat conduction caused by the contact can be reduced, which is conducive to ensuring the temperature stability of the heat dissipation table 18 and the controllability of the accuracy.

[0060] As shown in Figure 5 The second contact structure includes a second pointed protrusion 151, which is arranged on the edge of the lower surface of the substrate table 15. The pointed portion of the second pointed protrusion 151 is in abutment with the upper surface of the large molybdenum table 13, thereby achieving support of the substrate table 15. For example, the second pointed protrusion 151 is provided as a ring-shaped protrusion 131. The size of the second pointed protrusion 151 gradually decreases in a direction close to the heat dissipation table 18. The pointed portion of the second pointed protrusion 151 is in line contact with the large molybdenum table 13, which is conducive to reducing heat conduction.

[0061] As shown in Figure 3As shown, the first positioning protrusion is arranged on the upper surface of the microwave emission platform 12, and is arranged around the outer periphery of the large molybdenum platform 13 to achieve radial positioning of the large molybdenum platform 13. For example, the first positioning protrusion is arranged as an annular boss on the upper surface of the microwave emission platform 12. Figures 1-2 As shown, the second positioning protrusion is arranged on the side of the microwave emission platform 12 close to the metal platform 11, and is arranged on the lower surface of the microwave emission platform 12, and is arranged around the outer periphery of the metal platform 11 to achieve radial positioning of the metal platform 11. For example, the second positioning protrusion is arranged as an annular boss on the lower surface of the microwave emission platform 12. In this way, the first positioning protrusion and the second positioning protrusion can achieve radial positioning of the metal platform 11, the microwave emission platform 12, and the large molybdenum platform 13, which is beneficial to maintaining coaxiality of the three.

[0062] The substrate table system also includes a heat dissipation table 18. The support assembly is arranged in an annular shape and is arranged around the outer periphery of the heat dissipation table 18. The support assembly is supported on the edge of the substrate table 15 to achieve fixation of the substrate table 15. Specifically, the metal platform 11, the microwave emission platform 12, and the large molybdenum platform 13 are all arranged in an annular shape and are arranged around the outer periphery of the heat dissipation table 18. For example, the gap between the heat dissipation table 18 and the metal platform 11 is 0.1 mm. In this way, the support assembly is sleeved with the heat dissipation table 18, and the support assembly can limit the radial position of the heat dissipation table 18, thereby improving the positional stability of the heat dissipation table 18.

[0063] Moreover, the heat dissipation table 18 is arranged below the substrate table 15. The heat dissipation table 18 and the substrate table 15 are coaxial and are arranged in a spaced manner, and a gap is formed between the heat dissipation table 18 and the substrate table 15 to enable the heat dissipation table 18 to dissipate heat from the substrate table 15 in a radiation manner. For example, the heat dissipation table 18 and the substrate table 15 are both arranged in a cylindrical shape, and the center axes are on the same straight line. The upper side of the substrate table 15 is used for preventing the substrate, and the heat dissipation table 18 is located below the substrate table 15.

[0064] Specifically, the heat dissipation table 18 is internally provided with a heat dissipation channel. The heat dissipation channel is internally provided with a heat dissipation medium to dissipate heat from the side of the heat dissipation table 18 close to the substrate table 15. The temperature of the heat dissipation table 18 is lower than the temperature of the substrate table 15 to achieve radiation heat dissipation of the substrate table 15.

[0065] The upper surface of the heat dissipation platform 18 is close to one side of the substrate platform 15, and the upper surface of the heat dissipation platform 18 is formed with a plurality of heat dissipation portions arranged in sequence from the middle to the edge of the heat dissipation platform 18, and the heat dissipation coefficients of the heat dissipation portions located in the middle and the edge are greater than those of other heat dissipation portions (the other heat dissipation portions are located between the middle and the edge of the heat dissipation platform 18, and the number can be one, two or three), so that the heat dissipation coefficients of different positions of the upper surface of the heat dissipation platform 18 are different, and the temperature on the substrate platform 15 is compensated by non-uniform heat dissipation.

[0066] It can be understood that the number of heat dissipation portions can be three, four or five, and the preferred number is three, and the three heat dissipation portions are taken as an example for specific description, including the first heat dissipation portion 161, the second heat dissipation portion 162 and the third heat dissipation portion 163. The first heat dissipation portion 161, the second heat dissipation portion 162 and the third heat dissipation portion 163 are arranged in sequence from the middle to the edge of the upper surface of the heat dissipation platform 18, wherein the first heat dissipation portion 161 is circular and located in the middle of the heat dissipation platform 18, used for radiating heat dissipation to the middle area of the substrate platform 15; the second heat dissipation portion 162 is annular and surrounds the outer periphery of the first heat dissipation portion 161, used for radiating heat dissipation to the edge area close to the substrate platform 15; and the third heat dissipation portion 163 is annular and surrounds the outer periphery of the second heat dissipation portion 162, used for radiating heat dissipation to the edge area of the substrate platform 15. The heat dissipation coefficients of the first heat dissipation portion 161, the second heat dissipation portion 162 and the third heat dissipation portion 163 are different, and the heat dissipation coefficients of the first heat dissipation portion 161 and the third heat dissipation portion 163 are greater than that of the second heat dissipation portion 162, so that the heat dissipation coefficients of different positions of the upper surface of the heat dissipation platform 18 are different, and the temperature on the substrate platform 15 is compensated by non-uniform heat dissipation.

[0067] In the diamond growth process, the plasma above the substrate table 15 transmits temperature to the substrate table 15 by radiation, and due to the existence of the sheath layer at the edge of the plasma, the temperature of the middle region of the upper surface of the substrate table 15 is high, the temperature near the edge is low, and due to the existence of the sharp discharge at the edge region of the substrate table 15, the temperature of the edge region of the substrate table 15 is greater than the temperature near the edge region. The temperature of the upper surface of the substrate table 15 is transmitted to the lower surface of the substrate table 15 through the solid heat conduction in the substrate table 15, and the temperature of the lower surface of the substrate table 15 is radiated to the upper surface of the heat dissipation table 18. Due to the fact that the heat dissipation coefficients of the middle and edge heat dissipation portions of the heat dissipation table 18 are greater than the heat dissipation coefficients of other heat dissipation portions (the other heat dissipation portions are located between the middle and edge of the heat dissipation table 18, and the number thereof can be set to one, two or three), the heat conduction efficiency of the middle region of the substrate table is high, the heat conduction efficiency of the edge region is low, and the heat conduction efficiency of the edge region is high. In this way, the non-uniform compensation radiation heat dissipation can be performed on different regions of the substrate table 15, the radial temperature gradient of the upper surface of the substrate table 15 can be well balanced, and the radial temperature gradient of the substrate table 15 is better than 20K.

[0068] In this way, by designing the heat dissipation coefficients of the plurality of heat dissipation portions on the heat dissipation table 18, the non-uniform compensation radiation heat dissipation can be performed on different regions of the substrate table 15, the radial temperature gradient of the upper surface of the substrate table 15 can be well balanced, the diamond growth rate can be ensured to be uniform, the stress of the diamond crystal can be reduced, and the crack rate can be reduced.

[0069] It should be noted that the size relationship of the heat dissipation coefficients of the heat dissipation portions located at the middle and edge of the heat dissipation table 18 (i.e., the first heat dissipation portion 161 and the third heat dissipation portion 163) has a certain relationship with the specific structure of the substrate table system, and therefore is not specifically limited. Here, the heat dissipation coefficient of the first heat dissipation portion 161 is greater than the heat dissipation coefficient of the second heat dissipation portion 162.

[0070] In some embodiments, multiple heat dissipation parts (such as the first heat dissipation part 161, the second heat dissipation part 162, and the third heat dissipation part 163) are made of the same material (such as oxygen-free copper). The surface roughness of the heat dissipation parts located in the middle and edge of the heat dissipation platform 18 is greater than that of other heat dissipation parts (the other heat dissipation parts are located between the middle and edge of the heat dissipation platform 18, and the number can be set to one, two, or three). Since the smaller the surface roughness, the lower the emissivity and the worse the heat absorption effect, the heat dissipation coefficient of different areas (the first heat dissipation part 161, the second heat dissipation part 162, and the third heat dissipation part 163) on the heat dissipation platform 18 can be adjusted by adjusting the surface roughness. During diamond growth, the temperature radiation from the lower surface of the substrate stage 15 is transferred to multiple heat dissipation sections on the upper surface of the heat sink 18. The heat dissipation sections located in the middle and edges of the heat sink 18 (i.e., the first heat dissipation section 161 and the third heat dissipation section 163) have a higher surface roughness and emissivity, resulting in better heat absorption. Conversely, the heat dissipation section located between the middle and edges of the heat sink 18 (i.e., the second heat dissipation section 162) has a lower surface roughness and emissivity, resulting in poorer heat absorption. Thus, by designing different surface roughnesses for the same material, non-uniform heat dissipation is achieved in different areas of the substrate stage 15, which can better balance the radial temperature gradient on the upper surface of the substrate stage 15, ensuring that the radial temperature gradient of the substrate stage 15 is better than 20K.

[0071] like Figure 1 , 6 As shown, a radiative heat dissipation layer 16 is provided on the side (upper surface) of the heat sink 18 near the substrate stage 15. The radius of the radiative heat dissipation layer 16 is smaller than the radius of the upper side of the heat sink 18, so that multiple heat dissipation sections are formed on the radiative heat dissipation layer 16 and the upper surface of the heat sink 18. Specifically, the middle and edge of the radiative heat dissipation layer 16 form a first heat dissipation section 161 and a second heat dissipation section 162, respectively, and the edge of the heat sink 18 where the radiative heat dissipation layer 16 is not provided forms a third heat dissipation section 163. In this way, multiple heat dissipation sections are formed by the positional matching of the radiative heat dissipation layer 16 and the upper surface of the heat sink 18, resulting in a relatively simple structure that is easy to manufacture.

[0072] The heat sink 18 and the radiative heat dissipation layer 16 are both made of oxygen-free copper. The surface roughness of the middle part of the radiative heat dissipation layer 16 (i.e., the first heat dissipation part 161) is set to 1.6-3.2 micrometers, the surface roughness of the edge of the radiative heat dissipation layer 16 (i.e., the second heat dissipation part 162) is set to 0.3-1.2 micrometers, and the surface roughness of the edge of the heat sink 18 without the radiative heat dissipation layer 16 (i.e., the third heat dissipation part 163) is set to 0.1-0.6 micrometers.

[0073] In addition, the upper surface of the heat dissipation platform 18 can also be completely covered by the radiation heat dissipation layer 16, so that the middle region, the edge-approaching region and the edge region of the radiation heat dissipation layer 16 form the first heat dissipation part 161, the second heat dissipation part 162 and the third heat dissipation part 163 in sequence. The materials of the radiation heat dissipation layer 16 at different positions are the same, the surface roughness of the middle region and the edge region of the radiation heat dissipation layer 16 is greater than the surface roughness of the edge-approaching region of the radiation heat dissipation layer 16, and the specific surface roughness value is determined according to the specific situation.

[0074] In other embodiments, the plurality of heat dissipation parts are made of different materials (such as molybdenum, stainless steel, graphene, etc.), and the surface emissivity of the heat dissipation parts (the first heat dissipation part 161 and the third heat dissipation part 163) located in the middle and the edge of the heat dissipation platform 18 is greater than the surface emissivity of the heat dissipation part (the second heat dissipation part 162) located between the middle and the edge of the heat dissipation platform 18. In this way, by virtue of the different surface emissivities of different materials, non-uniform heat dissipation of different regions on the substrate table 15 is realized, and the radial temperature gradient on the surface of the substrate table 15 can be well balanced, so that the radial temperature gradient of the substrate table 15 is better than 20K. In a specific scheme, the first heat dissipation part 161 is made of molybdenum, the second heat dissipation part 162 is made of stainless steel, and the third heat dissipation part 163 is made of graphene.

[0075] Alternatively, the plurality of heat dissipation parts are coated with different surface emissivity coatings by being coated on different regions of the heat dissipation platform 18 to realize non-uniform heat dissipation of different regions of the substrate table 15.

[0076] In a specific scheme, the radius of the first heat dissipation part 161 is set to 15-18mm, and the radius of the second heat dissipation part 162 is set to 18-25mm. In this way, based on the size setting of the conventional substrate table 15, the first heat dissipation part 161 and the second heat dissipation part 162 can dissipate heat for specific regions on the substrate table 15, further improving the temperature distribution uniformity of the substrate table 15.

[0077] The substrate table system further comprises a lifting assembly connected to the heat dissipation table 18, which is used to drive the heat dissipation table 18 to move axially close to or away from the pole piece substrate table 15, thereby changing the gap size between the substrate table 15 and the heat dissipation table 18. After the diamond grows to a certain thickness, the thickening of the diamond layer deposited on the upper surface of the substrate table 15 will cause the temperature to rise. In order to keep the diamond at the optimal growth temperature (860±5 degrees Celsius) at all times, the heat dissipation table 18 is fine-tuned by the lifting assembly during the growth process to make the heat dissipation table 18 close to the substrate table 15. By reducing the gap between the upper surface of the heat dissipation table 18 and the lower surface of the substrate table 15, the heat dissipation capacity of the substrate table 15 can be improved, and the temperature of the diamond deposited on the upper surface of the substrate table 15 can be further reduced to the optimal growth temperature range. In this way, the temperature is controlled in real time during the growth process, and by adjusting the gap between the upper surface of the heat dissipation table 18 and the lower surface of the substrate table 15, the diamond can always be kept in the optimal growth temperature range, reducing the polycrystallization and graphitization of the diamond crystal surface, and improving the yield.

[0078] In the reaction chamber 3, an infrared temperature detector is arranged for detecting the temperature, and the temperature of the upper surface of the substrate table 15 in the reaction chamber 3 is obtained by the infrared temperature detector. According to the obtained temperature, the lifting assembly is controlled to act so that the heat dissipation table 18 is close to or away from the substrate table 15. For example, when the temperature of the upper surface of the substrate table 15 is high, the lifting table is controlled to drive the heat dissipation table 18 to be close to the substrate table 15.

[0079] In some preferred embodiments, the lifting assembly comprises an inner heat dissipation column 19, an outer heat dissipation column 20, and a first flexible pipe 21 (such as a corrugated pipe). The outer heat dissipation column 20 is sleeved outside the inner heat dissipation column 19 and can axially slide relative to the inner heat dissipation column 19. The outer heat dissipation column 20 is connected to the support assembly, for example, the top of the outer heat dissipation column 20 is connected to the metal table 11 by screws and O-rings (further can be connected by brazing). The upper part of the inner heat dissipation column 19 is connected to the heat dissipation table 18. One end of the first flexible pipe 21 is connected to the bottom of the outer heat dissipation column 20 by an O-ring, and the other end is connected to the lower side of the inner heat dissipation column 19 by an O-ring, thereby realizing the sealing between the inner heat dissipation column 19 and the outer heat dissipation column 20. The lower part of the inner heat dissipation column 19 and the outer heat dissipation column 20 can be fixed on the rack. When the heat dissipation table 18 is lifted, the motor system drives the inner heat dissipation column 19 to axially displace relative to the outer heat dissipation column 20, so that the heat dissipation table 18 is close to or away from the substrate table 15.

[0080] The outer side wall of the outer heat dissipation column 20 is provided with a second flexible pipe 22, such as a corrugated pipe. The outer side of the outer heat dissipation column 20 is provided with a flange plate 23, which can be axially displaced relative to the outer heat dissipation column 20, for sealing connection at the bottom of the reaction chamber 3. One end of the second flexible pipe 22 is sealingly connected with the outer side wall of the outer heat dissipation column 20, and the other end is connected with the flange plate 23, and an O-ring or the like structure is sealingly connected with the bottom of the reaction chamber 3, so as to seal the upper structure in the substrate table system in the reaction chamber 3.

[0081] The inner heat dissipation column 19 and the heat dissipation table 18 are provided with a first heat dissipation channel 17, and the first heat dissipation channel 17 is provided with a heat dissipation medium (such as cold water or cold gas). The first heat dissipation channel 17 is located in the inner heat dissipation column 19 and the heat dissipation table 18 to realize heat conduction of the inner heat dissipation column 19 and the heat dissipation table 18. The inlet 191 and the outlet 192 of the first heat dissipation channel 17 are arranged on the inner heat dissipation column 19 away from the heat dissipation table 18, so as to facilitate the inlet and outlet of the heat dissipation medium. The outer heat dissipation column 20 is provided with a second heat dissipation channel, and the second heat dissipation channel is provided with a heat dissipation medium (such as cold water or cold gas). The inlet 201 and the outlet of the second heat dissipation channel are arranged on the outer heat dissipation column 20 away from the support assembly, so as to facilitate the inlet and outlet of the heat dissipation medium.

[0082] The embodiment of the present application provides a MPCVD device, which comprises a reaction chamber and a substrate table system arranged in the reaction chamber, and the substrate table system is the substrate table system in the above embodiment. In this way, by designing the first heat dissipation part, the second heat dissipation part and the third heat dissipation part on the heat dissipation table, non-uniform compensation type radiation heat dissipation can be performed on different regions on the substrate table, the radial temperature gradient on the upper surface of the substrate table can be well balanced, the diamond growth rate is ensured to be consistent, the diamond crystal stress is reduced, and the chip rate is reduced.

[0083] As Figure 9As shown, the MPCVD apparatus includes a substrate table system 1 (mainly used for supporting the diamond substrate and providing heat dissipation for the diamond substrate during growth), a plasma 2, a reaction chamber 3, a quartz dielectric window 4, a mode conversion cavity 5, an antenna 6, a mode converter 7, three pin stubs 8 and a microwave generator 9. The microwave generator 9 emits 2.45 GHz frequency TE mode microwaves, the TE (Transverse Electric) mode microwaves are transmitted into the three pin stubs 8 through waveguides, the three pin stubs 8 can adjust the phase of the microwaves through the moving position of the pin stubs, the TE mode microwaves enter the mode conversion cavity 5 after passing through the three pin stubs 8, the antenna 6 in the mode conversion cavity 5 can convert the TE mode wave into a TEM (Transmission Line) mode wave, the TEM mode microwaves enter the reaction chamber 3 through the quartz dielectric window 4, the TEM mode microwaves can generate a resonant electric field inside the reaction chamber 3, when the pressure inside the reaction chamber 3 is appropriate, the strong electric field can ionize the reaction gas inside the reaction chamber, and generate a plasma 2 above the substrate table, the C-containing groups in the plasma 2 can diffuse onto the diamond substrate in a suitable temperature range, realizing homoepitaxial growth of the diamond.

[0084] The basic principles of the application are described above in combination with specific embodiments, but it should be pointed out that the advantages, advantages, effects and the like mentioned in the application are only examples and are not limiting, and these advantages, advantages, effects and the like cannot be considered as the application. Each embodiment must have the above-mentioned specific details.

[0085] The block diagram of the device, apparatus, equipment, system involved in the application is only an illustrative example and is not intended to require or imply that the connection, arrangement, configuration shown in the block diagram must be connected, arranged and configured. As those skilled in the art will recognize, these devices, apparatus, equipment, system can be connected, arranged and configured in any way. Words such as "include", "contain", "have" and the like are open-ended words, which mean "include but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0086] It should also be noted that in the device, equipment and method of the application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombination should be considered as equivalent solutions of the application.

[0087] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0088] It should be understood that the limiting words "first", "second", "third", "fourth", "fifth" and "sixth" used in the embodiments description of the present application are only used for more clearly describing the technical solutions, and cannot be used to limit the protection scope of the present application.

[0089] The above description has been presented for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the forms disclosed herein. Although several example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A substrate table system, characterized by, include: A microwave reflector and a large molybdenum stage stacked together; The substrate stage is located on the side of the large molybdenum stage away from the microwave reflector stage; The large molybdenum stage has an annular protrusion on the side away from the microwave reflector stage. The annular protrusion is coaxial with the substrate stage and surrounds the outer periphery of the substrate stage. The side of the substrate stage facing the large molybdenum stage has a second contact structure. The substrate stage contacts the large molybdenum stage through the second contact structure. The second contact structure can be configured as a line contact structure or a point contact structure.

2. The substrate table system of claim 1, wherein, The annular protrusion is spaced apart from the substrate stage; And / or, the surface of the annular protrusion on the side away from the large molybdenum stage is lower than the surface of the substrate stage on the side away from the large molybdenum stage.

3. The substrate table system of claim 1, wherein, The side of the annular protrusion near the substrate stage is perpendicular to the side of the large molybdenum stage away from the microwave reflector stage, and the side of the annular protrusion away from the substrate stage is set as an arc surface.

4. The substrate table system of claim 1, wherein, A retainer is provided on the side of the large molybdenum stage away from the microwave reflector stage. The retainer surrounds the outer periphery of the substrate stage to position the substrate stage. The annular protrusion is provided around the retainer.

5. The substrate table system of claim 4, wherein, The outer peripheral surface of the substrate stage contacts the cage through a first contact structure, which is configured as a line contact structure or a point contact structure.

6. The substrate table system of claim 5, wherein, The first contact structure includes a plurality of first pointed protrusions disposed inside the holder, the plurality of first pointed protrusions being distributed circumferentially along the substrate stage, and the tips of the first pointed protrusions abutting against the outer peripheral surface of the substrate stage.

7. The substrate table system of claim 1, wherein, The large molybdenum stage is arranged in a ring shape, and the side of the substrate stage facing the large molybdenum stage abuts against the large molybdenum stage.

8. The substrate table system of claim 7, wherein, The second contact structure includes a second pointed protrusion disposed on the side of the substrate stage facing the large molybdenum stage and located at the edge of the substrate stage, the tip of the second pointed protrusion abutting against the side of the large molybdenum stage.

9. The substrate table system of claim 1, wherein, The microwave reflector is provided with a first positioning protrusion on the side near the large molybdenum stage. The first positioning protrusion surrounds the outer periphery of the large molybdenum stage and can position the large molybdenum stage. A metal platform is provided on the side of the microwave reflector away from the large molybdenum platform. A second positioning protrusion is provided on the side of the microwave reflector away from the large molybdenum platform. The second positioning protrusion surrounds the outer periphery of the metal platform and can position the metal platform.

10. The substrate table system of claim 1, wherein, Also includes: Heat sink; Both the large molybdenum stage and the microwave reflector stage are arranged in a ring shape and surround the outer periphery of the heat sink. There is a gap between the substrate stage and the heat sink so that the heat sink can radiate heat to the substrate stage. The heat sink has multiple heat dissipation sections formed sequentially from the center to the edge on the side of the heat sink near the substrate stage. The heat dissipation coefficient of the heat dissipation sections located in the center and edge of the heat sink is greater than that of the heat dissipation sections located between the center and edge of the heat sink, so as to compensate for the temperature of the substrate stage through non-uniform heat dissipation.

11. The substrate table system of claim 10, wherein, The plurality of heat dissipation parts are made of the same material, and the surface roughness of the heat dissipation parts located in the middle and edge of the heat dissipation platform is greater than that of the heat dissipation parts located between the middle and edge of the heat dissipation platform.

12. The substrate table system of claim 10, wherein, The multiple heat dissipation parts are made of different materials, and the surface emissivity of the heat dissipation parts located at the middle and edges of the heat dissipation platform is greater than the surface emissivity of the heat dissipation parts located between the middle and edges of the heat dissipation platform.

13. The substrate table system of claim 10, wherein, The heat dissipation platform is provided with a radiation heat dissipation layer on the side close to the substrate platform, and the radius of the radiation heat dissipation layer is smaller than the radius of the heat dissipation platform, so as to sequentially form the multiple heat dissipation parts at the edges of the radiation heat dissipation layer and the heat dissipation platform.

14. The substrate table system of claim 13, wherein, The multiple heat dissipation parts are made of oxygen-free copper, the surface roughness of the middle part of the radiation heat dissipation layer is set to 1.6-3.2 microns, the surface roughness of the edges of the radiation heat dissipation layer is set to 0.3-1.2 microns, and the roughness of the edges of the heat dissipation platform is set to 0.1-0.6 microns.

15. The substrate table system of claim 10, wherein, Further comprising: A lifting assembly connected to the heat dissipation platform, the lifting assembly being used to drive the heat dissipation platform to approach or move away from the substrate platform along the axial direction.

16. An MPCVD apparatus, characterized by, A reaction chamber and a substrate platform system as claimed in any one of claims 1-15 arranged in the reaction chamber.

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