Heating device for chemical vapor deposition equipment and chemical vapor deposition equipment

Abstract

The invention discloses a heating device for chemical vapor deposition equipment and the chemical vapor deposition equipment, and belongs to the technical field of chemical vapor deposition equipment. According to the heating device for the chemical vapor deposition equipment and the chemical vapor deposition equipment, the induction heating coil can generate an alternating magnetic field according to an electric signal provided by the power supply module, and magnetic lines forming the magnetic field cut the conductive bearing table in the magnetic field to generate eddy current; the induced eddy current generates heat energy on the alternating-current impedance of the conductive bearing table according to the Joule thermal effect law, and then a heated object placed on the conductive bearing table can be heated. Furthermore, the induction heating coil is not a single-area induction heating coil, but is an induction heating coil which is arranged in a partitioned mode, so that on one hand, it can be guaranteed that the induction heating coil generates a strong alternating magnetic field signal, and on the other hand, the heated object can be evenly heated in a partitioned mode.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical vapor deposition equipment, and in particular to a heating device for chemical vapor deposition equipment and the chemical vapor deposition equipment. Background Art

[0002] Metal-organic Chemical Vapor Deposition (MOCVD) equipment includes a vacuum heating chamber, which is used to heat a wafer to perform a chemical deposition process.

[0003] At present, if a single-zone induction heating coil is used to heat the wafer, it is difficult to ensure the uniformity of temperature at various locations on the wafer when the wafer is heated due to the uneven distribution of the magnetic field generated by the single-zone induction heating coil. Uneven heating of the wafer will cause uneven thickness of thin film growth in the semiconductor epitaxial structure, which will in turn affect the working performance of the semiconductor device. Summary of the invention

[0004] The object of the present invention is to provide a heating device for chemical vapor deposition equipment and chemical vapor deposition equipment, which can heat a conductive support platform in different areas, thereby allowing a heated object placed on the conductive support platform to be heated evenly.

[0005] In order to achieve the above objectives, the following technical solutions are provided:

[0006] A heating device for chemical vapor deposition equipment, comprising:

[0007] A conductive support platform, wherein the conductive support platform is arranged in the reaction chamber;

[0008] A driving mechanism, the driving mechanism is used to drive the conductive bearing platform to rotate;

[0009] an induction heating coil, the induction heating coil being arranged in the reaction chamber and used for heating the conductive support platform; the induction heating coil comprising at least two induction coils which are independently controlled, the at least two induction coils comprising an i-th induction coil and a j-th induction coil, and the j-th induction coil surrounds the i-th induction coil; wherein 1≤i<j, and i and j are both positive integers;

[0010] A power supply module, wherein the power supply module is electrically connected to all the induction coils, and the power supply module can respectively adjust the frequency and phase coupling of the electrical signals of all the induction coils.

[0011] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the power supply module is used to make the frequencies of the electrical signals of at least two of the induction coils the same, and to make the phases of the electrical signals of at least two of the induction coils the same.

[0012] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, each of the induction coils is a planar coil;

[0013] The induction coils each include an extension start end and an extension end end;

[0014] Along the extending direction of the extending terminating end, the extending terminating end of the i-th induction coil is adjacent to the extending starting end of the (i+1)-th induction coil and is insulated from each other.

[0015] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the induction coil includes an uninterrupted curve surrounding the center and extending from the inside to the outside.

[0016] As a preferred technical solution of the heating device for chemical vapor deposition equipment, the induction coil includes a plurality of concentric coils, and the plurality of concentric coils are all wound from inside to outside around the same center to form the uninterrupted curve; or,

[0017] The uninterrupted curve is in a spiral involute structure.

[0018] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the induction heating device includes n induction coils;

[0019] The power module comprises n power output terminals, each of which corresponds to and is electrically connected to the induction coils one by one; wherein n≥2 and n is an integer;

[0020] There are two power output ends of the power supply outputting electrical signals with different powers and / or different frequencies; or, the powers, frequencies and phase angles of the electrical signals output by n power output ends can be independently adjusted.

[0021] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the conductive supporting platform includes a supporting portion for supporting the heated object, and the induction heating coil is arranged below the supporting portion.

[0022] As an optimal technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the conductive supporting platform also includes an enclosure portion, the enclosure portion is connected to the bottom of the supporting portion, the supporting portion and the enclosure portion are enclosed to form an installation cavity, and the induction heating coil is arranged in the installation cavity.

[0023] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the enclosing portion includes a side wall in contact with the bottom of the supporting portion;

[0024] A first gap is provided between the induction heating coil and the bearing portion; and / or,

[0025] A second gap is provided between the induction heating coil and the side wall; and / or,

[0026] The induction heating coil is used to heat the bearing portion; and / or,

[0027] The induction heating coil is used to heat the side wall.

[0028] As a preferred technical solution of the above-mentioned heating device for chemical vapor deposition equipment, the top surface of the conductive supporting platform is provided with a limiting structure, and the limiting structure can prevent the heated object placed on the conductive supporting platform from moving relative to the conductive supporting platform.

[0029] In order to achieve the above-mentioned purpose, a chemical vapor deposition device is also provided, comprising a reaction chamber and a heating device for chemical vapor deposition equipment as described in any one of the above items, wherein the conductive support platform and the induction heating coil are both arranged in the reaction chamber.

[0030] As a preferred technical solution of the above-mentioned chemical vapor deposition equipment, the chemical vapor deposition equipment also includes a ventilation device, which is arranged at the top of the reaction chamber and is used to introduce reaction gas. The bottom of the reaction chamber is provided with an exhaust port.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In the heating device and chemical vapor deposition equipment for chemical vapor deposition equipment of the present invention, the induction heating coil can generate an alternating magnetic field according to the electrical signal provided by the power module, and the magnetic lines of force constituting the magnetic field cut the conductive support platform in the magnetic field to generate eddy currents, and the induced eddy currents generate heat energy on the AC impedance of the conductive support platform itself according to the Joule thermal effect law, thereby heating the heated object placed on the conductive support platform. Further, the induction heating coil includes at least two induction coils that are independently controlled, and the at least two induction coils include the i-th induction coil and the j-th induction coil, and the j-th induction coil surrounds the i-th induction coil, that is, the induction heating coil is not a single-zone induction heating coil, but an induction heating coil arranged in a partition, so that by adjusting the frequency and phase of the power module, the coupling effect between the induction coils is eliminated, so that the heat obtained by each area of ​​the heated object can be accurately controlled by power adjustment, reducing energy loss, and realizing fine control of the temperature field, on the one hand, it can ensure that the induction heating coil generates a strong alternating magnetic field signal, and on the other hand, it can heat the heated object in a partitioned and uniform manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a first cross-sectional structure of a chemical vapor deposition device provided by an embodiment of the present invention;

[0034] Figure 2 A schematic cross-sectional structure diagram of a heating device for chemical vapor deposition equipment provided by an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of the principle of a heating device for chemical vapor deposition equipment provided by an embodiment of the present invention;

[0036] Figure 4 is a structural schematic diagram of an induction heating coil provided by an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of the structure of another induction heating coil provided by an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of a coupling waveform of two induction coils provided in an embodiment of the present invention;

[0039] Figure 7 Another coupling waveform schematic diagram of two induction coils provided in an embodiment of the present invention;

[0040] Figure 8 A schematic diagram of temperature changes when a heating device for chemical vapor deposition equipment provided in an embodiment of the present invention heats an object to be heated;

[0041] Fig. 9A schematic diagram of electrical connections of a control module in a heating device for a chemical vapor deposition device provided in an embodiment of the present invention;

[0042] Fig.10 A schematic diagram of a second cross-sectional structure of a chemical vapor deposition device provided in an embodiment of the present invention;

[0043] Fig.11 A schematic structural diagram of a conductive support platform provided in an embodiment of the present invention.

[0044] In the figure:

[0045] 10. Induction heating coil; 101. Induction coil; 1011. i-th induction coil; 1012. j-th induction coil; 1013. i+1-th induction coil; 11. Extension starting end; 12. Extension ending end; 100. Center hollow coil; 20. Power module; 30. Conductive support platform; 31. Supporting part; 301. Installation cavity; A. First support member; B. Second support member; 40. Object to be heated; 70. Motor; 701. Rotating shaft; 80. Reaction chamber; 801. Equipment body; 90. Tray; 901. Placement slot. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0050] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0053] like Figure 1-Figure 11As shown, this embodiment provides a heating device for chemical vapor deposition equipment and a chemical vapor deposition equipment, the chemical vapor deposition equipment includes a reaction chamber 80 and a heating device for chemical vapor deposition equipment, the heating device for chemical vapor deposition equipment includes an induction heating coil 10, a power module 20, a conductive support platform 30 and a driving mechanism, the conductive support platform 30 is arranged in the reaction chamber 80; the driving mechanism is used to drive the conductive support platform 30 to rotate; the induction heating coil 10 is arranged in the reaction chamber 80 and is used to heat the conductive support platform 30; the induction heating coil 10 includes at least two induction coils 101 that are independently controlled, the at least two induction coils 101 include an i-th induction coil 1011 and a j-th induction coil 1012, and the j-th induction coil 1012 surrounds the i-th induction coil 1011; wherein 1≤i<j, and i and j are both positive integers; the power module 20 is electrically connected to all the induction coils 101, and the power module 20 can adjust the frequency and phase coupling of the electrical signals of all the induction coils 101 respectively.

[0054] The power module 20 can output an electrical signal, and the induction heating coil 10 is electrically connected to the power module 20, and can then generate an alternating magnetic field according to the electrical signal provided by the power module 20. The magnetic lines of force that constitute the magnetic field cut the conductive support platform 30 in the magnetic field, generating eddy currents. The induced eddy currents generate heat energy on the AC impedance of the conductive support platform 30 itself according to Joule's law of thermal effect, and can transfer the heat to the heated object 40 on the conductive support platform 30 through the conductive support platform 30, so that the heated object 40 is heated.

[0055] Further, the induction heating coil 10 includes at least two induction coils 101 that are independently controlled, and the at least two induction coils 101 include an i-th induction coil 1011 and a j-th induction coil 1012, and the j-th induction coil 1012 surrounds the i-th induction coil 1011, that is, the induction heating coil 10 is not a single-zone induction heating coil, but an induction heating coil 10 including multiple independent induction coils 101. In other words, the induction heating coil 10 is a zoned induction heating coil, which can ensure that the induction heating coil 10 generates a strong alternating magnetic field signal on the one hand, and multiple induction coils 101 interact with each other to generate a strong alternating magnetic field signal, and on the other hand, the heated object 40 can be heated in a zoned and uniform manner.

[0056] In this embodiment, the conductive support platform 30 rotates around its central axis under the drive of the driving mechanism, thereby driving the heated object 40 to rotate, and torque can be transmitted between the conductive support platform 30 and the heated object 40 through friction. Furthermore, when the heated object 40 is placed on the conductive support platform 30, the central axis of the heated object 40 coincides with the central axis of the conductive support platform 30, which is conducive to ensuring stability during rotation.

[0057] It is understandable that by adjusting the output voltage of the power module 20, the frequency and phase coupling of the electrical signals of all the induction coils 101 can be adjusted. Specifically, by adjusting the output voltage of the power module 20, the alternating current of the induction coil 101 can be adjusted, and then the frequency and phase coupling of the alternating current can be adjusted.

[0058] It should be noted that the multiple independent induction coils 101 are not arranged in an array in space, but are surrounded. In this way, the mutual induction between adjacent induction coils 101 can reduce the interference between each other, and a stronger alternating magnetic field signal can be generated under the action of the electrical signal, thereby improving the conversion efficiency of the electrical energy signal and the thermal energy signal.

[0059] Exemplarily, the induction heating coil 10 may include two induction coils 101 or multiple induction coils 101, and the embodiment of the present invention does not specifically limit the number of induction coils 101. For ease of description, in this embodiment, the induction heating coil 10 includes two induction coils 101 as an example for explanation, and the jth induction coil 1012 surrounds the ith induction coil 1011. It can be understood that the jth induction coil 1012 is an outer induction heating coil, and the ith induction coil 1011 is an inner induction heating coil. In other words, the ith induction coil 1011 heats the central area of ​​the conductive support platform 30, and the jth induction coil 1012 heats the edge areas on both sides of the conductive support platform 30, so that the conductive support platform 30 can be heated in different areas, and then the temperature of different areas of the conductive support platform 30 can be controlled by the output power and / or output frequency of the power module 20, so that when the heated object 40 is heated, the uniformity of the temperature of each part of the heated object 40 can be ensured.

[0060] It is understandable that if Figure 4 As shown, the jth induction coil 1012 may be adjacent to the ith induction coil 1011. Exemplarily, the jth induction coil 1012 may also be not adjacent to the ith induction coil 1011, that is, other induction coils 101 are spaced between the jth induction coil 1012 and the ith induction coil 1011.

[0061] For example, the heated object 40 may be a substrate, or a tray 90 for carrying the substrate, and the tray 90 may be placed horizontally on the conductive carrier 30, so that the conductive carrier 30 transfers heat to the tray 90 and then to the substrate. During the epitaxial structure growth process, the substrate needs to be heated uniformly to ensure the uniformity of the thickness of the deposited film, thereby ensuring the stability and reliability of the semiconductor device.

[0062] Exemplarily, the material of the induction heating coil 10 can be oxygen-free copper, which has a low outgassing rate and is suitable for a high vacuum environment. The outside of the induction heating coil 10 can be provided with a coating, such as a gold coating, which has stable chemical properties at high temperatures. This can prevent the induction heating coil 10 from direct contact with the reaction gas and prevent the induction heating coil 10 from being corroded.

[0063] Optionally, the conductive support platform 30 is used as a heat storage body, and preferably a graphite material is used. The conductive support platform 30 can be integrally formed or composed of several parts.

[0064] Optional, such as Figure 4 and Figure 5 As shown, each induction coil 101 is a planar coil, and all the induction coils 101 are located in the same plane; the driving mechanism drives the conductive support platform 30 to rotate parallel to the plane, that is, the conductive support platform 30 rotates parallel to the plane of the induction heating coil 10. It should be noted that all the induction coils 101 can be located in approximately the same plane to reduce the manufacturing accuracy of the induction heating coil 10 and reduce the cost.

[0065] In other embodiments, the induction coils 101 may not be located in the same plane, that is, there may be a height difference. Since induction heating is sensitive to distance changes, the heating efficiency of each induction coil 101 on the heated object 40 may be changed by independently adjusting the gap between each induction coil 101 and the heated object 40, thereby adjusting the temperature field.

[0066] Optionally, the induction coil 101 includes an extension start end 11 and an extension end end 12; along the extension direction of the extension end end 12 (eg Figure 4 ), the extension end 12 of the i-th induction coil 1011 is adjacent to the extension start end 11 of the (i+1)-th induction coil 1013 and is insulated from each other.

[0067] Specifically, along the extension direction X of the extension end end 12, the extension end end 12 of the i-th induction coil 1011 and the extension start end 11 of the i+1-th induction coil 1013 are adjacent and insulated, that is, any two adjacent induction coils 101 are disconnected, so that the induction heating coil 10 can be ensured to include multiple induction coils 101. In other words, the induction heating coil 10 is arranged in partitions, and the power module 20 can be electrically connected to the induction heating coil 10 to achieve partition heating of the heated object 40 on the conductive support platform 30.

[0068] Optional, reference Figure 4 and Figure 5 The induction coil 101 includes an uninterrupted curve surrounding the center and extending from the inside to the outside.

[0069] As a feasible implementation method, refer to Figure 5 , the induction coil 101 may include a plurality of concentric coils, that is, the i-th induction coil 1011 and the j-th induction coil 1012 are both concentric coils, each concentric coil is wound from the inside to the outside around the same center, so that the induction coil 101 can form an uninterrupted curve extending from the inside to the outside around the center, that is, the plurality of concentric coils are wound from the inside to the outside around the same center to form an uninterrupted curve. Figure 5 It can be seen that the radii of the multiple concentric coils are different, and the multiple concentric coils are concentrically arranged, and two adjacent concentric coils are connected by a connecting line segment, so that the multiple concentric coils are all wound from the inside to the outside around the same center to form an uninterrupted curve.

[0070] Specifically, the center of the concentric coil is located on the central axis of the conductive support platform 30 .

[0071] Figure 5 Only the technical solution that the induction coil 101 includes the i-th induction coil 1011 and the j-th induction coil 1012 is shown. It can be understood that the induction coil 101 can also include more concentric coils, and the centers of the multiple concentric coils can all be the center of the conductive support platform 30 to achieve heating of the heated object 40. The embodiment of the present invention does not specifically limit the number of concentric coils.

[0072] As another possible implementation, refer to Figure 4 The induction coil 101 includes a spirally arranged coil, that is, the uninterrupted curve is a spiral involute structure, which can ensure that the induction coil 101 generates a strong alternating magnetic field under the action of the electrical signal, thereby improving the conversion efficiency of the electrical energy signal and the thermal energy signal.

[0073] Specifically, the starting point of the spiral involute structure is located on the central axis of the conductive support platform 30 .

[0074] Exemplarily, the shape and density of the spirally arranged induction heating coil can be adjusted to adjust the distribution of magnetic lines of force.

[0075] When a single-zone induction heating coil is used in the prior art, specifically, although the single-zone induction heating coil can also meet the heating function, due to the structural limitations of the planar coil, a weak area of ​​the induced electric field will be formed above the central area of ​​the single-zone induction heating coil, resulting in a lower temperature in the central area of ​​the conductive support platform, which cannot meet the uniformity requirements of the temperature field of the entire piece for single-piece growth, and will directly affect the growth quality of the epitaxial crystal.

[0076] In order to solve the above problems, the induction heating coil 10 includes n induction coils 101; the power module 20 includes n power output terminals, which correspond to and are electrically connected to the induction coils 101 one by one; wherein n≥2 and n is an integer; the power, frequency and phase angle of the electrical signals output by the n power output terminals can be adjusted, thereby facilitating the control of the power, frequency and phase angle of the electrical signals of the corresponding induction coils 101 through the power output terminals.

[0077] When the induction heating coil 10 in the embodiment of the present invention is used to heat the heated object 40, the power of each induction coil 101 can be independently controlled. By changing the power ratio of each induction coil 101, the temperature difference between the central area and the outer area of ​​the conductive support platform 30 can be reduced, and the uniformity of the temperature field can be improved. That is, in the radial direction of the partitioned induction heating coil, the temperature variation of the heated object 40 is small, that is, the heated object 40 is heated more evenly.

[0078] It can be understood that, for the induction heating coil 10, the inductive reactance of the coil should match the inductive reactance and capacitive reactance in the circuit. When the two are approximately equal, the circuit resonates, at which time the current in the circuit reaches the maximum and the efficiency of induction heating is the highest.

[0079] It should be noted that in this embodiment, the induction heating coil 10 includes two independently controlled induction coils 101, namely the i-th induction coil 1011 and the j-th induction coil 1012. The inductance and resistance of the two induction coils 101 are different, that is, the natural resonant frequencies of the two are inconsistent. If they are simply adjusted according to the maximum induction heating efficiency of each, it is likely to appear as follows: Figure 6 The situation shown will lead to magnetic flux interference and power coupling problems, reduced heating efficiency, increased energy loss, and poor temperature field adjustability.

[0080] Optional, such as Figure 7 As shown, the power module 20 is used to make the frequencies of the electrical signals of at least two induction coils 101 the same, and make the phases of the electrical signals of at least two induction coils 101 the same. Through the inductive reactance, capacitive reactance and phase shift adjustment of the power module 20, the same frequency and phase of each independent induction coil are achieved, and the coupling effect between the induction coils 101 is eliminated, so that the heat obtained by each area of ​​the heated object 40 can be accurately controlled by power adjustment, reducing energy loss and achieving fine control of the temperature field.

[0081] like Figure 8As shown, in the prior art, when a single-zone induction heating coil is used for heating, the temperature of the heated object varies greatly in the radial direction of the single-zone coil. When the induction heating coil 10 of this embodiment is used for heating, by making at least two induction coils 101 heat at the same frequency and phase, the heating speed is faster, the temperature can reach 1600°C, and the induction heating coil 10 has a longer life, a reliable structure, and does not require frequent maintenance.

[0082] Specifically, the induction heating coil 10 includes n independently controlled induction coils 101; the power supply module 20 includes n power output terminals, that is, the number of the power output terminals is equal to that of the induction coils 101, that is, each power output terminal corresponds to an induction coil 101, and the power output terminals correspond to the induction coils 101 one by one and are electrically connected, so that the heating temperature of the conductive support platform 30 by the corresponding induction coil 101 can be controlled according to the power output of each power output terminal, and the penetration depth of the conductive support platform 30 by the corresponding induction coil 101 can be controlled according to the frequency output of each power output terminal. In this way, each induction coil 101 can be independently controlled through the power output terminal, thereby improving the control accuracy of the heating temperature.

[0083] It should be noted that the power of the electric signal output from the output end of the power supply will affect the heating temperature of the heated object 40. That is, the higher the power of the electric signal, the higher the heating temperature of the heated object 40, and the faster the heating speed. Due to the skin effect, the frequency of the electric signal output from the output end of the power supply will affect the penetration depth of the induced current. Generally speaking, the greater the frequency of the electric signal, the shallower the penetration depth. In other words, when the frequency of the electric signal output from the output end of the power supply is large, the alternating current is concentrated on the surface of the induction heating coil 10 close to the conductive support platform 30, that is, the current will be concentrated in the thin layer on the surface of the conductive support platform 30. The closer to the surface of the conductive support platform 30, the greater the current density, and the closer to the inside of the conductive support platform 30, the smaller the current density. That is, the heating position is more concentrated on the surface, and the penetration depth of the conductive support platform 30 is shallow. Therefore, in order to achieve uniform heating of the heated object 40, the frequency of the electric signal is usually set to about 20kHz.

[0084] In other embodiments, there are two power output terminals that output electrical signals with different powers and / or frequencies. In other words, at least one power output terminal outputs electrical signals with different powers and / or frequencies from the other power output terminals.

[0085] Exemplarily, when the heated object 40 is a substrate, it is necessary to control the heating temperature to ensure uniform heating of the substrate. Furthermore, there are two power output terminals with different electrical signal powers and / or frequencies to ensure the uniformity of temperature at different positions of the substrate. Exemplarily, when the density of the spirally arranged induction heating coils in the induction coil 101 is different, the power output terminal of the power supply electrically connected to the relatively sparse induction coil 101 can be controlled to output a large electrical signal power, so that the conductive support platform 30 corresponding to each induction coil 101 can be ensured to be uniformly heated, which is beneficial to uniform heating of the substrate, thereby improving the reliability and stability of the deposited epitaxial wafer.

[0086] In other embodiments, the power module 20 includes a power output terminal, and the multiple induction coils 101 are electrically connected to the power output terminal. That is, one power output terminal can be electrically connected to multiple induction coils 101, so that on the one hand, the connection structure is simple, and on the other hand, the power and / or frequency of the electrical signal output from the power output terminal to each induction coil 101 are the same, so that the temperature of the conductive support platform 30 corresponding to the i-th induction coil 1011 and the j-th induction coil 1012 can be the same, which is conducive to uniform heating of the heated object 40 on the conductive support platform 30.

[0087] Exemplarily, the driving mechanism includes a motor 70 ; the motor 70 is connected to the conductive support platform 30 , and is used to drive the conductive support platform 30 to rotate in a plane parallel to the induction heating coil 101 .

[0088] Specifically, the chemical vapor deposition equipment includes a motor magnetic fluid vacuum transmission device, which integrates a sealed vacuum magnetic fluid, a high-precision motor and a controller (not shown in the figure) to form a compact and high-performance sealed rotation system. Exemplarily, the motor 70 can be a magnetic fluid motor, and the rotating shaft 701 of the magnetic fluid motor is connected to the second support member B and the first support member A in sequence. The first support member A is connected to the conductive support platform 30, and the connection method can be a screw connection or a boss pit is set to support and rotate the drive. The magnetic fluid motor is rotated to drive the conductive support platform 30 to rotate in a plane parallel to the induction heating coil 10, and then the substrate located on one side of the conductive support platform 30 can be driven to rotate at a high speed, so that the temperature of the substrate is consistent along the circumferential direction, eliminating the temperature singularity caused by the asymmetric or irregular appearance of the induction heating coil 10.

[0089] Specifically, the conductive support platform 30 includes a support portion 31 for supporting the heated object 40, and the induction heating coil 10 is arranged below the support portion 31 so that the alternating magnetic field signal generated by the induction heating coil 10 can better penetrate the support portion 31 to ensure the heating effect.

[0090] Optionally, the conductive support platform 30 further includes an enclosure portion, which is connected to the bottom of the support portion 31. The support portion 31 and the enclosure portion enclose a mounting cavity 301. The induction heating coil 10 is disposed in the mounting cavity 301 to protect the induction heating coil 10, which is beneficial to prolonging the service life of the induction heating coil 10. Figure 2 and Fig.10 As shown, in this embodiment, the first support member A and the second support member B are connected to form an enclosure.

[0091] It can be understood that the enclosing portion includes a side wall in contact with the bottom of the bearing portion 31. In this embodiment, the side wall is the first support member A mentioned above.

[0092] It should be noted that the induction heating coil 10 can heat the bearing portion 31. The induction heating coil 10 can also heat the side wall. With such a configuration, the heating effect is better.

[0093] like Figure 2 and Fig.10 As shown, optionally, a first gap is provided between the induction heating coil 10 and the bearing portion 31. Optionally, a second gap is provided between the induction heating coil 10 and the side wall.

[0094] By providing the first gap and the second gap, interference between the conductive support platform 30 and the induction heating coil 10 can be avoided when the conductive support platform 30 rotates.

[0095] Optionally, the width of the first gap is 2 mm-50 mm. Optionally, the width of the second gap is 2 mm-50 mm.

[0096] Such a configuration can not only avoid interference between the conductive support platform 30 and the induction heating coil 10 during rotation, but also improve the heating effect of the induction heating coil 10 on the side wall of the support portion 31 .

[0097] Exemplarily, the width of the first gap may be any value among 2mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm. Exemplarily, the width of the second gap may be any value among 2mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm.

[0098] In this embodiment, the heated object 40 is a tray 90, and the tray 90 carries the substrate, and the tray 90 is fixed on the conductive support platform 30. Further, the tray 90 is provided with a limiting structure for preventing the substrate from moving relative to the tray 90, so as to prevent the position of the substrate from shifting during the rotation of the conductive support platform 30. Exemplarily, the limiting structure is a placement groove 901 opened on the tray 90, and the substrate is placed in the placement groove 901 to prevent the substrate from moving relative to the tray 90.

[0099] Optionally, the tray 90 carries a single piece of film, and the size of the film may be 6 inches, 8 inches or larger, which is not limited here.

[0100] Specifically, the central axis of the tray 90 and the central axis of the film both coincide with the central axis of the conductive support platform 30 .

[0101] In other embodiments, the top surface of the conductive support platform 30 may be provided with a limiting structure, which can prevent the heated object 40 placed on the conductive support platform 30 from moving relative to the conductive support platform 30, so as to prevent the position of the heated object 40 from shifting during the rotation of the conductive support platform 30, thereby not only improving the uniformity of heating of the heated object 40, but also improving the effect of the heated object 40 reacting in the reaction chamber 80. It can be understood that the transmission of torque between the conductive support platform 30 and the heated object 40 through the limiting structure is more reliable than the transmission of torque through friction.

[0102] Exemplarily, the limiting structure is a placement groove opened on the top surface of the conductive supporting platform 30 , and the heated object 40 can be placed in the placement groove to prevent the heated object 40 from moving relative to the conductive supporting platform 30 .

[0103] In this embodiment, the reaction chamber 80 is a vacuum chamber. Specifically, the chemical vapor deposition device further includes a device body 801, and the device body 801 is provided with the reaction chamber 80. Exemplarily, the material of the device body 801 is a metal material.

[0104] Exemplarily, the first support member A and the second support member B are preferably made of graphite, which can have sufficient strength even in a vacuum and at high temperature.

[0105] Optional, reference Fig.10 and Fig.11The induction heating coil 10 includes a central hollow coil 100, that is, the induction heating coil 10 is an internal hollow structure. Due to the skin effect of the alternating current, the alternating current on the induction heating coil 10 is mainly concentrated on the surface of the induction heating coil 10. Therefore, under the condition that the heating performance is not affected, the interior of the induction heating coil 10 can be made into a hollow structure. In this way, while the induction heating coil 10 is conductively heated, a coolant can be introduced through the cooling system to greatly reduce the temperature of the induction heating coil 10 itself, thereby increasing the life of the induction heating coil 10 and achieving the purpose of less maintenance or even maintenance-free, which is more suitable for large-scale production.

[0106] Exemplarily, when the induction heating coil 10 includes multiple induction coils 101, the extended starting ends 11 of the multiple induction coils 101 can all be connected to the same current input line, and the extended terminating ends 12 of the multiple induction coils 101 can all be connected to the same current output line, and the current input line and the current output line can both be located in the hollow area of ​​the central hollow coil 100. In this way, the setting method of the induction heating coil 10 is simple and the structure is compact.

[0107] Optionally, the wall thickness of the central hollow coil 100 is in the range of 1 mm to 5 mm, thereby ensuring that the magnetic field formed by the induction heating coil 10 meets the requirements on the one hand, and taking into account its own strength and cooling effect on the other hand.

[0108] Exemplarily, the wall thickness of the central hollow coil 100 may be any value of 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0109] In this embodiment, the reaction chamber 80 is a vertical airflow reaction chamber; the airflow direction in the vertical airflow reaction chamber is perpendicular to the horizontal direction.

[0110] Specifically, the chemical vapor deposition equipment also includes a ventilation device, which is arranged at the top of the reaction chamber 80, and is used to introduce reaction gas into the reaction chamber. The bottom of the reaction chamber 80 is provided with an exhaust port, so that the flow direction of the gas flow in the reaction chamber is perpendicular to the horizontal direction. Optionally, the exhaust port is connected to an exhaust system.

[0111] It can be understood that the conductive carrier 30 and the substrate are arranged in the reaction chamber 80, and the reaction gas is introduced into the reaction chamber 80 through the ventilation device, and transported to the substrate placed on the conductive carrier 30 for epitaxial reaction or thin film deposition, and the induction heating coil 10 is configured to heat the conductive carrier 30 and the substrate. The reaction gas enters the reaction chamber 80 to participate in the epitaxial structure growth process, that is, the epitaxial structure is uniformly grown on the substrate. In the process of heating the substrate, the induction heating coil 10 can be operated through the current input line and the current output line in the power module, and then the substrate is uniformly heated through the conductive carrier 30 to ensure the quality of the epitaxial structure. The residual gas after the reaction can be discharged to the outside of the reaction device through the exhaust system.

[0112] In summary, the heating device for chemical vapor deposition equipment provided by the embodiment of the present invention, the induction heating coil can generate an alternating magnetic field according to the electrical signal provided by the power module, and the magnetic lines of force constituting the magnetic field cut the conductive support platform 30 in the magnetic field to generate eddy currents. The induced eddy currents generate heat energy on the AC impedance of the conductive support platform 30 itself according to the Joule's thermal effect law, and thus the heated object 40 placed on the conductive support platform 30 can be heated. Further, the induction heating coil 10 includes at least two induction coils 101 that are independently controlled, and each induction coil 101 includes a spirally arranged induction heating coil, so that it can be ensured that the induction coil 101 generates a strong alternating magnetic field under the action of the electrical signal, thereby improving the conversion efficiency of the electrical energy signal and the thermal energy signal. At least two induction coils 101 include an i-th induction coil 1011 and a j-th induction coil 1012, and the j-th induction coil 1012 surrounds the i-th induction coil 1011, that is, the induction heating coil 10 is not a single-zone induction heating coil, but is arranged in zones, so that on the one hand, it can ensure that the induction heating coil 10 generates a strong alternating magnetic field signal, and on the other hand, by making the heating power of different coils of the induction heating coil 10 different, the temperature distribution of different areas of the heated object 40 can be made more uniform. Further, when multiple induction heating coils 10 work at the same time, there will be mutual interference of magnetic flux and power coupling problems, and power decoupling can be performed through an equivalent circuit mathematical model to accurately control the heat obtained by the corresponding area of ​​each coil; and the same frequency and same phase technology is used to solve the coupling problem between coils. That is, by controlling the operating frequency of each induction heating coil 10 to be the same, the output current is kept in the same phase, ensuring that the output power between each coil is not affected, and achieving the optimal uniform temperature level.

[0113] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A heating device for chemical vapor deposition equipment, characterized in that: include: A conductive support platform, wherein the conductive support platform is arranged in the reaction chamber; A driving mechanism, the driving mechanism is used to drive the conductive bearing platform to rotate; an induction heating coil, the induction heating coil being arranged in the reaction chamber and used for heating the conductive support platform; the induction heating coil comprising at least two induction coils which are independently controlled, the at least two induction coils comprising an i-th induction coil and a j-th induction coil, and the j-th induction coil surrounds the i-th induction coil; wherein 1≤i<j, and i and j are both positive integers; A power supply module, wherein the power supply module is electrically connected to all the induction coils, and the power supply module can respectively adjust the frequency and phase coupling of the electrical signals of all the induction coils.

2. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: The power supply module is used to make the frequencies of the electrical signals of at least two induction coils the same, and to make the phases of the electrical signals of at least two induction coils the same.

3. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: Each of the induction coils is a planar coil; The induction coils each include an extension start end and an extension end end; Along the extending direction of the extending terminating end, the extending terminating end of the i-th induction coil is adjacent to the extending starting end of the (i+1)-th induction coil and is insulated from each other.

4. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: The induction coil includes an uninterrupted curve surrounding the center and extending from the inside to the outside.

5. The heating device for chemical vapor deposition equipment according to claim 4, characterized in that: The induction coil comprises a plurality of concentric circle coils, and the plurality of concentric circle coils are all wound from the inside to the outside around the same center to form the uninterrupted curve; or, The uninterrupted curve is in a spiral involute structure.

6. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: The induction heating device comprises n induction coils; The power module comprises n power output terminals, each of which corresponds to and is electrically connected to the induction coils one by one; wherein n≥2 and n is an integer; There are two power output ends of the power supply outputting electrical signals with different powers and / or different frequencies; or, The power, frequency and phase angle of the electrical signals output by the n power output terminals can be adjusted independently.

7. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: The conductive supporting platform comprises a supporting portion for supporting the object to be heated, and the induction heating coil is arranged below the supporting portion.

8. The heating device for chemical vapor deposition equipment according to claim 7, characterized in that: The conductive supporting platform further includes an enclosure portion, the enclosure portion is connected to the bottom of the supporting portion, the supporting portion and the enclosure portion are enclosed to form an installation cavity, and the induction heating coil is arranged in the installation cavity.

9. The heating device for chemical vapor deposition equipment according to claim 8, characterized in that: The enclosing portion includes a side wall in contact with the bottom of the bearing portion; A first gap is provided between the induction heating coil and the bearing portion; and / or, A second gap is provided between the induction heating coil and the side wall; and / or, The induction heating coil is used to heat the bearing portion; and / or, The induction heating coil is used to heat the side wall.

10. The heating device for chemical vapor deposition equipment according to claim 1, characterized in that: A limiting structure is provided on the top surface of the conductive supporting platform, and the limiting structure can prevent the heated object placed on the conductive supporting platform from moving relative to the conductive supporting platform.

11. Chemical vapor deposition equipment, characterized in that It comprises a reaction chamber and a heating device for chemical vapor deposition equipment as described in any one of claims 1 to 10, wherein the conductive support platform and the induction heating coil are both arranged in the reaction chamber.

12. The chemical vapor deposition equipment according to claim 11, characterized in that: The chemical vapor deposition equipment also includes a ventilation device, which is arranged at the top of the reaction chamber and is used to introduce reaction gas. The bottom of the reaction chamber is provided with an exhaust port.

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