Ceramic heating disc lead electrode connection structure and connection method thereof

Abstract

The application discloses a ceramic heating disc leading-out electrode connecting structure and a connecting method thereof. The connecting structure comprises a joint, a leading-out electrode and a connecting hole which are embedded in a ceramic base. The leading-out electrode comprises an electrode tube segment and an electrode rod segment. A first gap is arranged between the electrode tube segment and the connecting hole, and a second gap is arranged between the electrode rod segment and the electrode tube segment. The width of the gaps can avoid cracking due to thermal expansion and ensure the uniformity of heat conduction. After alumina powder, zirconia powder and silicon oxide powder are ball milled in a certain proportion with ethanol as a medium, the connecting hole and the connecting position of the leading-out electrode are sprayed, ethanol is volatilized through drying, the whole component is put into a vacuum brazing furnace for brazing, the brazing temperature is 800-1200 DEG C, the vacuum degree is less than or equal to 10^ ‑ 4mmHg, the holding time is 10-180 min, and after heating, the component is cooled to room temperature under the protection of an inert atmosphere, and a ceramic composite powder coating with a void of 30-60% is formed.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing equipment technology, specifically to a ceramic heating plate lead-out electrode connection structure and its connection method. Background Technology

[0002] Chemical vapor deposition (CVD) equipment is a key piece of equipment in semiconductor chip manufacturing. The core issue of CVD equipment is how to ensure the uniformity and repeatability of material growth. As a component of CVD equipment, the fabrication method of the electrodes and heating structure contained in the chip heating plate will affect the uniformity of the heating plate temperature, and thus affect the uniformity and repeatability of the chip growth process.

[0003] CVD is a key piece of equipment in the semiconductor chip manufacturing process. The key issue of CVD core technology is ensuring the uniformity and repeatability of material growth. The most significant difference between CVD systems from different manufacturers lies in the reaction chamber structure. The chip heating plate is an important component of this structure, which enables the silicon wafer to be uniformly heated to a certain temperature and allows the plasma formed by the ionization of gas to be uniformly deposited on the silicon wafer. To achieve this function, an RF electrode and a heating component are pre-embedded in the heating plate. The RF electrode and the electrode plate of the CVD equipment form a capacitor-like function to generate plasma from the gas. In order to supply external power to the electrode and heating component, the RF electrode and heating component need to be welded to external electrode rods respectively.

[0004] Existing chip heating pads are primarily ceramic heating pads, which generally consist of a heating pad body and a ceramic tube connected together. The heating pad body houses radio frequency (RF) electrodes and heating components. To ensure proper operation of the RF electrodes and heating components, multiple connection holes are typically formed on the heating pad body to expose the connection points of the RF electrodes and heating components. Lead-out electrodes (usually nickel rods) pass through these connection holes and connect to the connection points of the RF electrodes and heating components respectively. During the development of this technology, to ensure a tighter connection between the lead-out electrodes and the RF electrodes and heating components made of different materials and to prevent damage to the RF electrodes and heating components from the lead-out electrodes, connectors are generally provided at the connection points of the RF electrodes and heating components. These connectors, such as connectors for the RF electrodes and the two-pole connectors for the heating components, have various structural shapes, such as cylindrical shapes. For example, one existing ceramic heating pad relies solely on threaded connections, causing the end of the lead-out electrode to abut against the connector. This does not effectively secure the lead-out electrode and can easily lead to unstable contact between the lead-out electrode and the connector.

[0005] When the radio frequency electrode and the heating component are welded to the external electrode rod, the heating plate requires a high temperature of 1700-1900 degrees Celsius to be manufactured. Therefore, tungsten or molybdenum materials with high temperature resistance and thermal expansion coefficients close to those of aluminum nitride ceramics are needed. However, the thermal expansion coefficients of the two materials are significantly different from those of nickel, the electrode rod material. Therefore, the difference in thermal expansion between the two materials must be considered when welding them together. The design must ensure that the ceramic at the connection point between the tungsten / molybdenum and nickel does not crack due to the expansion of nickel during the welding process. Thus, how to weld the two materials together plays a decisive role in the manufacture of the heating plate. If the welding is not done well, the manufactured heating plate will be unusable, resulting in serious losses.

[0006] Patent document JP2012216786A discloses a component for a semiconductor manufacturing apparatus, comprising: a ceramic substrate having a wafer mounting surface; an electrode embedded within the ceramic substrate; an electrode exposure portion, which is part of the electrode and is exposed from a surface opposite to the wafer mounting surface of the ceramic substrate; a power supply component for supplying power to the electrode; and a bonding layer between the ceramic substrate and the power supply component, which, while bonding the power supply component and the ceramic substrate, electrically connects the power supply component and the electrode exposure portion. The bonding layer is formed using an AuGe-based alloy, an AuSn-based alloy, or an AuSi-based alloy as the bonding material. For the ceramic substrate and the power supply component, the difference D between the coefficients of thermal expansion of the power supply component and the coefficient of thermal expansion of the ceramic substrate is selected to satisfy the following range: -2.2 ≤ D ≤ 6, with units of ppm / K, and a bonding strength of 3.5 MPa or more at 200°C.

[0007] The biggest limitation of this technology is that the ceramic matrix is ​​selected as the main component of a component composed of Al2O3, AlN, MgO, Y2O3 and SiC, and the power supply component is selected from a component composed of Ti, Cu, Ni, Mo, CuW, W and their alloys and FeNiCo alloys. These materials result in a large difference in the coefficient of thermal expansion.

[0008] Therefore, the patent literature emphasizes that the difference in thermal expansion coefficient D between the ceramic substrate and the power supply component must meet the following range: -1.5≤D≤6, where the unit is ppm / K. If the difference in expansion coefficients within the above range is too large, the required expansion gap will be large, making the electrode rod easily damaged under constant insertion and removal or inappropriate insertion and removal force. At the same time, the increased gap will increase the amount of filler used, thus increasing the cost. Summary of the Invention

[0009] To address the aforementioned technical problems, this application provides a ceramic heating plate lead-out electrode connection structure and connection method.

[0010] One embodiment of this application provides a ceramic heating plate lead-out electrode connection structure, including a connector, lead-out electrode, and connection hole embedded in a ceramic substrate. The lead-out electrode includes an electrode tube segment and an electrode rod segment, a first gap is provided between the electrode tube segment and the connection hole, and a second gap is provided between the electrode rod segment and the electrode tube segment.

[0011] The electrode tube segment includes an optical aperture segment and a pre-fixed segment. The diameter of the pre-fixed segment is larger than the diameter of the optical aperture segment, and the optical aperture segment is located above and / or below the pre-fixed segment.

[0012] The electrode tube segment and the connector form a first weld layer, and the electrode rod segment and the bottom of the electrode tube segment form a second weld layer.

[0013] According to some embodiments of this application, the welding layer is one of gold, gold-nickel alloy, silver-copper-nickel alloy and Kovar alloy, the electrode rod segment and the electrode tube segment are both made of pure nickel, and the ceramic substrate is made of aluminum nitride.

[0014] One embodiment of this application provides a ceramic heating plate lead-out electrode connection structure, including a connector, lead-out electrode, and connection hole embedded in a ceramic substrate. The lead-out electrode includes an electrode tube segment and an electrode rod segment. The electrode tube segment is provided with an inner hole, and the end of the electrode rod segment is provided with a protrusion. The protrusion and the inner hole form a convex-concave insertion structure.

[0015] A first gap is provided between the electrode tube segment and the connecting hole, and a second gap is provided between the electrode rod segment and the inner hole of the electrode tube segment;

[0016] The electrode tube segment includes an optical aperture segment and a pre-fixed segment, wherein the diameter of the pre-fixed segment is larger than the diameter of the optical aperture segment;

[0017] The electrode tube segment and the joint form a first weld layer;

[0018] The width of the first gap is 0.1-3mm, and the width of the second gap is 0.1-3mm.

[0019] According to some embodiments of this application, the inner hole of the convex-concave insertion structure is a closed cavity.

[0020] According to some embodiments of this application, a third welding layer is provided around the electrode rod segment at a predetermined position along the length direction of the electrode rod segment, as required by design.

[0021] According to some embodiments of this application, the weld layer is one of gold, gold-nickel alloy, silver-copper-nickel alloy, and Kovar alloy.

[0022] According to some embodiments of this application, both the electrode rod segment and the electrode tube segment are made of pure nickel, and the ceramic substrate is made of aluminum nitride.

[0023] According to some embodiments of this application, a connecting strip is formed at the end of the electrode rod segment, and the connecting strip is inserted into the inner hole.

[0024] According to some embodiments of this application, the difference in expansion coefficient between the substrate and the lead-out electrode is 8.6 to 14 ppm / K.

[0025] According to some embodiments of this application, a ceramic composite powder coating with a void ratio of 30% to 60% is sprayed onto the interface between the connecting hole and the lead-out electrode.

[0026] According to some embodiments of this application, the main components of the ceramic composite powder are two or more of alumina, zirconium oxide, calcium oxide, silicon oxide, barium oxide, lithium oxide and boron oxide. The particle size of the alumina and zirconium oxide is 0.1-2 μm, the mass ratio of alumina to zirconium oxide is 0.25-4, and the mass of other oxides is less than 50% of the total mass.

[0027] According to some embodiments of this application, a circular groove is opened at the bottom end of the external thread of the electrode tube section, and a circular surface is machined at the tip of the internal thread of the connecting hole, and a gap of about 0.05-0.5mm is pre-set at the contact point between the two.

[0028] One embodiment of this application provides a method for connecting leads of a ceramic heating plate, including the following steps:

[0029] A connector with a connection hole is formed on the heating plate body. The connection hole includes a light hole and a pre-fixed hole. One end of the lead-out electrode is formed into a light hole segment and a pre-fixed segment. A first solder is placed on the surface of the connector in the connection hole. The pre-fixed segment is screwed into the pre-fixed hole. A first gap is formed between the outer side of the light hole segment and the inner wall of the light hole. The end of the light hole segment is welded to the connector to form a first weld layer.

[0030] According to some embodiments of this application, the method for connecting the lead-out electrode of a ceramic heating plate further includes: forming an electrode tube segment and an electrode rod segment with the lead-out electrode, wherein the aperture segment and the pre-fixed segment are located in the electrode tube segment, the electrode tube segment has an inner hole, the opening end of the inner hole is the end away from the aperture segment, and the inner hole extends at least to the pre-fixed segment; placing a second solder at the bottom end of the inner hole, one end of the electrode rod segment extending into the inner hole, and forming a second gap between the outer side of the electrode rod segment and the inner wall of the inner hole; and welding one end of the electrode rod segment to the bottom end of the inner hole to form a second solder layer.

[0031] According to some embodiments of this application, the method for connecting the lead-out electrode of the ceramic heating plate further includes: forming an electrode tube segment and an electrode rod segment with the lead-out electrode, wherein the aperture segment and the pre-fixed segment are located in the electrode tube segment, the electrode tube segment has an inner hole, the opening end of the inner hole is the end away from the aperture segment, and the inner hole extends at least to the pre-fixed segment; placing a third solder at the end of the electrode tube segment away from the aperture segment; and welding the electrode rod segment to the end of the electrode tube segment to form a third solder layer.

[0032] According to some embodiments of this application, a connecting strip is formed at the end of the electrode rod segment, and the connecting strip is inserted into the inner hole.

[0033] According to some embodiments of this application, the welding conditions for forming the first weld layer are: vacuum welding, the solder being one of gold, gold-nickel alloy, Kovar alloy, or silver-copper-nickel alloy, and the welding temperature being 800-1200℃.

[0034] According to some embodiments of this application, the welding conditions for forming the second welding layer are: vacuum welding, the solder being one of gold, gold-nickel alloy, Kovar alloy, or silver-copper-nickel alloy, and the welding temperature being 800-1200℃.

[0035] According to some embodiments of this application, the welding conditions for forming the third welding layer are: vacuum welding, the solder being one of gold, gold-nickel alloy, Kovar alloy, or silver-copper-nickel alloy, and the welding temperature being 800-1200℃.

[0036] The technical solution described in this application has the following advantages over the prior art:

[0037] (1) The lead electrode connection structure and connection method of this application form a light hole segment and a pre-fixed segment for the lead electrode, and the connection hole is set as a light hole and a pre-fixed hole. When the pre-fixed segment is screwed into the pre-fixed hole, a first gap is formed between the light hole segment and the light hole, and the end of the light hole segment is welded to the connector. The screwing of the pre-fixed segment into the pre-fixed hole can ensure that the lead electrode is stable and does not shake. The existence of the first gap is used to buffer the expansion of the lead electrode when welding at high temperature, and avoids cracking caused by the different thermal expansion coefficients of different materials around the weld when the lead electrode is welded to the connector, thus ensuring good electrical performance. At the same time, the width of the first gap is set to 0.1-3mm, which can avoid cracking due to thermal expansion and also ensure the uniformity of heat conduction.

[0038] (2) The lead electrode connection structure and connection method of this application, by setting a second gap, provides a buffer space during the expansion of the pre-fixed section when the electrode rod section is welded to the inner hole and when the open hole section is welded to the connector, thereby reducing the cracking phenomenon caused by the different thermal expansion coefficients of different materials at the threaded connection and ensuring good electrical performance; at the same time, setting the width of the second gap to 0.1-3mm can avoid cracking due to thermal expansion and also ensure the uniformity of heat conduction.

[0039] (3) The lead-out electrode connection structure and connection method of this application, by designing the lead-out electrode as an electrode tube segment and an electrode rod segment, can avoid cracking caused by different thermal expansion coefficients during welding in the first gap, while directly welding the end of the electrode tube segment and the end of the electrode rod segment. At this time, the inner hole is a buffer space during welding. At the same time, the electrode rod segment and the electrode tube segment are firmly connected and will not shake. Furthermore, by setting a connecting strip, the connecting strip is inserted into the inner hole before welding, which further ensures the strength between the two.

[0040] (4) The lead electrode connection structure and connection device of this application, by setting the first gap, the second gap and the inner hole as expansion buffer spaces, improves the power conduction performance of the connection device by reducing the cracking phenomenon caused by different thermal expansion coefficients during welding. At the same time, by setting the threaded connection, the stability between the lead electrode and the heating plate is guaranteed. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings, without exceeding the scope of protection claimed by this application.

[0042] Figure 1 This is a schematic diagram of the lead-out electrode connection structure of the ceramic heating plate of this application. Figure 1 .

[0043] Figure 2 This is a schematic diagram of the electrode connection method for the ceramic heating plate of this application.

[0044] Figure 3 This is a schematic diagram of the lead-out electrode connection structure of the ceramic heating plate of this application. Figure 2 .

[0045] Figure 4 This is a schematic diagram of the lead-out electrode connection structure of the ceramic heating plate of this application. Figure 3 .

[0046] Among them, heating plate body; 2-connector; 3-connecting hole; 31-light hole; 32-pre-fixing hole; 4-lead-out electrode; 41-electrode tube segment; 42-electrode rod segment; 411-light hole segment; 412-pre-fixing segment; 413-inner hole; 421-connecting strip; 51-first gap; 52-second gap; 61-first welding layer; 62-second welding layer; 63-third welding layer.

[0047] Figure 5 yes Figure 4 Detailed schematic diagram.

[0048] Figure 6 This is a schematic diagram of the materials used in the structure of the ceramic heating plate of this application, wherein: 1S - aluminum nitride ceramic; 2S - RF electrode; 3S, 4S, 5S - B welding layer; 6S - heating element or heating wire; 7S - aluminum nitride ceramic tube; 8S, 9S, 10S - metallic nickel rod.

[0049] Figure 7 This is a schematic diagram of the materials used in the structure of the ceramic heating plate of this application, wherein: 1D - RF electrode; 2D - upper heating plate or heating wire; 3D - lower heating plate or heating wire; 4D, 5D, 6D - gold-nickel welded together; 7D - upper and lower heating plate or heating wire connecting electrode; 8D - aluminum nitride ceramic tube; 9D, 10D, 11D, 12D, 13D - metallic nickel rod.

[0050] Figure 8 This is a schematic diagram of the materials used in the lead-out electrode connection structure of the ceramic heating plate of this application, wherein: 1a, 1b - aluminum nitride ceramic; 2a, 2b - tungsten or molybdenum electrode; 3a, 3b - void; 4a, 4b - nickel tube; 5a, 5b, 6a, 6 - weld layer; 7a, 7b - void; 8a, 8b - nickel rod.

[0051] Figure 9 This is a schematic diagram of the lead-out electrode of this application, wherein 1-aluminum nitride ceramic; 2-connector; 3-ceramic surface; 4-lead-out electrode.

[0052] Figure 10 This is a schematic diagram of the lead-out electrode thread of this application, wherein: 5-thread gap; 6-welding wire.

[0053] Figure 11 This is a schematic diagram showing the changes in the coefficients of thermal expansion of aluminum nitride and nickel at different temperatures. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0055] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] The ceramic matrix mentioned in this invention mainly refers to aluminum nitride ceramics, but if it is needed for heating other equipment, alumina ceramics are also applicable in order to reduce costs.

[0057] Table 1 shows the thermal expansion coefficients of aluminum nitride and nickel at different ambient temperatures, and the difference between them. Figure 11 The curves showing the changes in the coefficients of thermal expansion of aluminum nitride and nickel at different temperatures are shown.

[0058] Table 1

[0059]

[0060] See Table 1 and Figure 11 The difference in the coefficient of thermal expansion between aluminum nitride and nickel in this invention ranges from 8.6 to 14 ppm / k.

[0061] The heating element of this invention is a molybdenum or tungsten heating element with a thickness of 0.1-0.5 mm. Alternatively, a spring-type heating element can be used, with a spring diameter of 2-8 mm and a wire diameter of 0.2-1.0 mm. The different thicknesses and diameters in the two different heating methods are mainly to meet the requirements of different thermal resistances, so that the substrate can be provided with a working temperature of 350-700°C.

[0062] The metal mesh described in this invention is a uniform square or hexagonal mesh with a thickness of 0.2-0.5 mm. The metal mesh needs to be acid-treated and then cleaned.

[0063] As shown in this invention, the threads of the electrode tube segment are specially designed. A circular groove is opened at the bottom of the external thread of the electrode tube segment, and a circular surface is machined at the tip of the internal thread of the connecting hole. There is a gap of about 0.05-0.5mm at the contact point between the two to ensure that the welding wire spool can be screwed into the ceramic thread when it is at the bottom of the thread of the pre-fixed section of the electrode tube segment. Then, vacuum brazing is performed to further fix the electrode tube segment and the connecting hole together by melting the welding wire.

[0064] The ceramic tube described in this invention is made of aluminum nitride or alumina ceramic. After being dry-pressed or isostatically pressed, the ceramic tube is processed into a tubular shape and then sintered under normal pressure for later use.

[0065] The ceramics described in this invention are aluminum nitride and aluminum oxide ceramics. The scope of this invention is mainly used in semiconductor equipment, but not limited to such equipment. The welding method described in this invention avoids cracking that may occur due to the difference in expansion coefficients between the ceramic and the electrode rod through reasonable design, thus ensuring good electrical performance.

[0066] The electrode welding described in this invention requires vacuum welding at a pressure below 10^-4 mmHg.

[0067] The welding temperature used in this invention is 800℃-1200℃. This welding temperature can ensure that the heating plate has good electrical performance at an operating temperature of 350-700℃, and will not cause changes in resistance due to secondary sintering of the heating resistor due to excessive welding temperature, nor will it cause ceramic breakdown during RF process due to secondary diffusion of molybdenum metal.

[0068] The lead-out electrode used in this invention is a pure nickel rod.

[0069] The solder used in this invention is one of gold, Kovar alloy, silver-copper-nickel alloy, or gold-nickel alloy (such as an 82% gold and 18% nickel alloy).

[0070] The sintering temperature of the aluminum nitride heating plate of the present invention is 1700℃-1900℃, and the sintering temperature of the alumina heating plate is 1580℃-1650℃.

[0071] The aluminum nitride ceramic tube described in this invention is connected to a heating plate and sintered at a temperature of 1400℃-1700℃.

[0072] The alumina ceramic tube described in this invention is connected to a heating plate and sintered at a temperature of 1000℃-1550℃.

[0073] The heating plate has RF electrodes and heating electrodes pre-embedded inside. In order to connect the RF electrodes and heating electrodes to an external power source in the future, the electrodes need to be led out, so the connection holes are machined on the ceramic surface.

[0074] This invention mainly relates to a welding reinforcement method for the lead-out electrodes of a ceramic heating plate used in semiconductor devices. The heating plate structure is as follows: Figure 6 and Figure 7 As shown, the heating plate mainly consists of heating plate bodies 1S and 14D and connecting tubes 7S and 8D. Electrode rods are distributed inside the connecting tubes and are connected to the metal sheets inside the heating plate. The heating plate body mainly consists of heating elements 6S, 2D, and 3D and electrode mesh 2S and 1D. The heating elements and electrode mesh are first pre-embedded in the aluminum nitride ceramic plate. After hot pressing and sintering, the heating plate and tubes are brazed together. Then, the heating components and radio frequency electrodes inside the heating plate are connected to an external power supply through electrode connectors to form a circuit. How to weld the electrode rods requires consideration of the temperature resistance of the solder used. It needs to be able to ensure that the solder and the welded parts will not detach due to the operating temperature of 350-700℃ during the operation of the heating plate. Therefore, solder with a welding temperature higher than 700℃ needs to be selected. In addition, it is necessary to consider the manufacturing process of welding the molybdenum sheet and nickel electrode rod inside the heating plate together with solder. The ceramic will not crack due to the mismatch of the thermal expansion coefficients of the two materials. Therefore, an expansion gap is set, which needs to be greater than the difference in the expansion coefficients of the two materials.

[0075] The connector is a positive and negative connector pre-embedded in the heating plate. The surface of the positive and negative connector is exposed through subsequent processing. The lead-out electrodes are soldered to the surface of the connector with solder. Finally, the power is turned on for testing.

[0076] The connector shown in this invention uses a threaded connection of an electrode tube segment. The thread is specially designed, with a circular groove at the bottom of the external thread of the electrode tube segment and a circular surface machined at the tip of the internal thread of the connection hole. There is a gap of about 0.05-0.5mm at the contact point between the two to ensure that the welding wire spool can be screwed into the thread of the connection hole in the pre-fixed section of the electrode tube segment. Then, vacuum brazing is performed to further fix the electrode tube segment and the ceramic connection hole together by melting the welding wire.

[0077] By winding welding wire around the threaded bottom end of the pre-fixed section of the electrode tube and screwing it into the pre-fixed hole of the connection hole, the connection hole and the pre-fixed section of the electrode tube are tightly connected by brazing after the welding wire melts. This strengthens the electrode's stability.

[0078] Without the addition of welding wire, the lead-out electrode and the connecting hole can swing at a 15-degree angle. With this design, no swing angle appears, indicating that the connecting hole and the lead-out part of the electrode are tightly and firmly connected.

[0079] Appendix Figure 5-10 As shown, the methods for fixing and strengthening the lead-out electrodes are divided into external fixing and internal fixing.

[0080] Specific implementation method of external fixation:

[0081] Both the electrode rod segment and the electrode tube segment of the lead-out electrode are made of metallic nickel. During welding, the bottom end of the electrode tube segment is placed into the solder, and the electrode tube segment is tightened by thread, as shown in the figure. Then, ceramic composite powder is sprayed on the interface between the connecting hole 3 and the lead-out electrode 4. The entire component is placed in a vacuum brazing furnace for brazing. The brazing temperature is 800-1200℃, the vacuum degree is less than or equal to 10^-4 mmHg, and the maximum temperature holding time is 10-180 min. After heating, it can be cooled under an inert atmosphere.

[0082] Preparation and application of ceramic composite powder: The main components of ceramic composite powder are two or more of the following: alumina, zirconium oxide, calcium oxide, silicon oxide, barium oxide, lithium oxide, and boron oxide. The particle size of alumina and zirconium oxide is 0.1-2 μm, the mass ratio of alumina to zirconium oxide is 0.25-4, and the mass of other oxides is less than 50% of the total mass. After ball milling the above compounds in a certain proportion with ethanol as the medium for 2 hours, the mixture is sprayed onto the connection positions of the connecting hole 3 and the lead electrode 4 shown in the figure. The ethanol is evaporated by drying. The entire component is then placed in a vacuum brazing furnace for brazing. The brazing temperature is 800-1200℃, the vacuum degree is 10^-4 mmHg, and the maximum temperature holding time is 10-180 min. After heating, the mixture is cooled to room temperature under an inert atmosphere.

[0083] For example, 500g of alumina powder and 500g of zirconium oxide powder can be ball-milled using ethanol as the medium and then sprayed onto the connection positions 3 and 4 in the diagram. After drying to evaporate the alcohol, the entire component is placed in a vacuum brazing furnace for brazing at a temperature of 1200℃, a vacuum of 10^-4 mmHg, and a maximum holding time of 10-180 minutes. After heating, it is cooled to room temperature under an inert atmosphere. The resulting sprayed surface is a non-dense white sponge coating with a porosity of 60%. Due to the porosity, cracks will not occur due to the expansion coefficients of the heating plate ceramic and the nickel rod.

[0084] For example, 400g of alumina powder, 500g of zirconium oxide powder, and 100g of silicon oxide powder are ball-milled using ethanol as the medium. The resulting powder is then sprayed onto the connection points of connecting hole 3 and lead-out electrode 4 as shown in the diagram. The ethanol is evaporated by drying, and the entire component is then placed in a vacuum brazing furnace for brazing at 1100℃, a vacuum of 10^-4 mmHg, and a maximum holding time of 10-180 minutes. After heating, the component is cooled to room temperature under an inert atmosphere. The resulting coating is a non-dense white sponge coating with 50% porosity. Because of the porosity, cracks will not occur due to the expansion coefficients of the heating plate ceramic and the lead-out electrode.

[0085] For example, a composite powder consisting of 400g alumina powder, 200g zirconium oxide powder, 200g silica powder, and 100g calcium oxide powder can be ball-milled using ethanol as the medium. This mixture is then sprayed onto the connection points of connecting hole 3 and lead-out electrode 4 as shown in the diagram. The ethanol is evaporated by drying, and the entire component is then placed in a vacuum brazing furnace for brazing at 800℃, a vacuum of 10^-4 mmHg, and a maximum holding time of 10-180 minutes. After heating, the component is cooled to room temperature under an inert atmosphere. The resulting coating is a non-dense white sponge coating with a porosity of 45%. Due to the presence of some porosity, cracks will not occur due to the expansion coefficients of the heating plate ceramic and the lead-out electrode.

[0086] For example, a composite powder consisting of 400g alumina powder, 200g zirconium oxide powder, 200g silica powder, and 100g calcium oxide powder can be ball-milled using ethanol as the medium. This mixture is then sprayed onto the connection points of connecting hole 3 and lead-out electrode 4 as shown in the diagram. The ethanol is evaporated by drying, and the entire component is then placed in a vacuum brazing furnace for brazing at 950℃, a vacuum of 10^-4 mmHg, and a maximum holding time of 10-180 minutes. After heating, the component is cooled to room temperature under an inert atmosphere. The resulting coating is a non-dense white sponge coating with a porosity of 30%. Due to the presence of some porosity, cracks will not occur due to the expansion coefficients of the heating plate ceramic and the lead-out electrode.

[0087] Specific implementation method of internal fixation:

[0088] The ceramic part is divided into a large rounded corner at the top and a small rounded corner at the bottom. The gap between the two rounded corners is just enough to insert a welding wire with a diameter of 0.1-1mm.

[0089] The implementation method is as follows: the welding wire is pre-coiled around the bottom of the thread of the electrode tube section, and then screwed into the thread of the connecting hole together with the welding wire. The two are then welded together by vacuum brazing, which can effectively increase the stability of the lead-out electrode and the connecting hole.

[0090] Example 1

[0091] like Figure 3 As shown, an embodiment of this application provides a ceramic heating plate lead-out electrode connection structure. The ceramic heating plate is suitable for semiconductor chemical vapor deposition equipment. The lead-out electrode connection structure includes: a connector 2 disposed within the heating plate body 1, a connection hole 3 disposed on the heating plate body 1, and a lead-out electrode 4.

[0092] Connector 2 is used to connect the radio frequency electrode and the heating element inside the heating plate 1. In this embodiment, there are multiple connectors 2, which are respectively connected to the two poles of the radio frequency electrode and the heating element.

[0093] The connecting hole 3 corresponds to the connector 2, exposing the surface of the connector 2 to facilitate the connection between the connector 2 and the lead electrode 4. The connecting hole 3 includes a light hole 31 and a pre-fixing hole 32, with the light hole 31 closer to the connector 2 than the pre-fixing hole 32. In this embodiment, the pre-fixing hole 32 is a threaded hole.

[0094] The lead-out electrode 4 includes a light-hole section 411 and a pre-fixing section 412. In this embodiment, the pre-fixing section 412 is provided with external threads, and the pre-fixing section 412 is threadedly connected to the pre-fixing hole 32. The light-hole section 411 is located inside the light-hole 31. A first gap 51 is formed between the outer side of the light-hole section 411 and the inner wall of the light-hole 31. Optionally, the width of the first gap 51 is 0.1-3mm, preferably 1.5mm. This application does not limit the shape of the first gap 51. In this embodiment, the first gap 51 is a cylindrical structure. The end of the light-hole section 411 is connected to the connector 2 through a first welding layer 61.

[0095] like Figure 2 As shown, the method for connecting the lead-out electrodes of the ceramic heating plate in this embodiment includes the following steps:

[0096] S101. A connecting hole 3 is formed on the heating plate to expose the connector 2. The connecting hole 3 includes a smooth hole 31 and a pre-fixing hole 32. In this embodiment, the pre-fixing hole 32 is a threaded hole.

[0097] This embodiment does not impose specific limitations on the shape of the optical aperture 31, but a cylindrical aperture is preferred. Generally, the diameter of the pre-fixed hole 32 is larger than the diameter of the optical aperture 31. The shape of the connector 2 is not specifically limited, but it is preferably cylindrical, such as a cylinder or a cube. The material of the connector 2 is preferably the same as or similar to the RF electrode and heating component it is connected to, preferably the same, such as commonly used tungsten or molybdenum materials.

[0098] S102. A light aperture section and a pre-fixing section are formed at one end of the lead-out electrode. This embodiment does not specifically limit the structure of the lead-out electrode 4, such as a cylindrical shape, and its material can be any commonly used electrode material in the art. In this embodiment, a nickel rod is preferred. In this embodiment, the pre-fixing section is provided with external threads.

[0099] S103. Place the first solder on the joint surface inside the connection hole, screw the pre-fixed section into the pre-fixed hole, and form a first gap between the outer side of the optical hole section and the inner wall of the optical hole.

[0100] Specifically, the first solder is placed on the surface of the connector 2 inside the connecting hole 3, and the pre-fixed section 412 is screwed into the pre-fixed hole 32, forming a first gap 51 between the outer side of the aperture section 411 and the inner wall of the aperture 31. The width of the first gap 51 is 0.1-3mm, preferably 1.5mm. The shape of the first gap 51 is not specifically limited, and it is determined according to the shape of the aperture section 411 and the aperture 31. In this embodiment, the first gap 51 is a cylindrical structure.

[0101] S104. Weld the end of the aperture section to the joint to form the first weld layer.

[0102] Specifically, all the above structures are placed in a vacuum furnace and the first solder is vacuum welded at high temperature to form the first weld layer 61. The welding conditions can be selected based on the materials used. Optionally, in this embodiment, the first solder is a gold-nickel alloy, the proportion of which can be selected as needed, and its shape is not specifically limited, such as wire or sheet. The welding temperature is 800-1200℃, preferably 1000℃. Of course, other types of solder can also be selected, such as gold, gold-nickel alloy, Kovar alloy, silver-copper-nickel alloy, etc., and a suitable solder can be selected according to the specific welding temperature.

[0103] The lead electrode connection structure and method of this embodiment form a lead electrode with a light aperture segment and a pre-fixed segment, and the connection hole is set as a light aperture and a pre-fixed hole. When the pre-fixed segment is screwed into the pre-fixed hole, a first gap is formed between the light aperture segment and the light aperture, and the end of the light aperture segment is welded to the connector. Screwing the pre-fixed segment into the pre-fixed hole ensures that the lead electrode is stable and does not wobble. The first gap is used to buffer the expansion of the lead electrode during high-temperature welding, avoiding cracking caused by the different thermal expansion coefficients of different materials around the weld when welding the lead electrode to the connector, thus ensuring good electrical conductivity. At the same time, setting the width of the first gap to 0.1-3mm can not only avoid cracking due to thermal expansion, but also ensure the uniformity of heat conduction. Figure 1 The fourth section lacks an inner hole, causing cracks to occur at the contact point between the connecting hole and the lead-out electrode after welding.

[0104] Example 2

[0105] like Figure 3 As shown, the lead electrode connection structure and connection method in this embodiment are a further improvement on Embodiment 1, the difference being:

[0106] The electrode 4 is led out to form an electrode tube segment 41 and an electrode rod segment 42. An aperture segment 411 and a pre-fixed segment 412 are located within the electrode tube segment 41. The electrode tube segment 41 has an inner hole 413, the opening end of which is away from the aperture segment 411, and the inner hole 413 extends at least to the entire length of the pre-fixed segment 412. Preferably, the inner hole 413 extends at least 1 mm beyond the entire length of the pre-fixed segment 412.

[0107] The second solder is placed at the bottom end of the inner hole 413, and one end of the electrode rod 22 extends into the inner hole 413, forming a second gap 52 between the outer side of the electrode rod 42 and the inner wall of the inner hole 413. Optionally, the width of the second gap 52 is 0.1-3mm, preferably 1.5mm. The shape of the second gap 52 is not specifically limited, and it is determined according to the shape of the electrode rod 42 and the inner hole 413. In this embodiment, the second gap 52 is a cylindrical structure.

[0108] A second solder is used to weld one end of the electrode rod segment 42 to the bottom end of the inner hole 413 to form a second solder layer 62. The welding conditions can be selected based on the materials used. In this embodiment, the second solder is a gold-nickel alloy, the proportion of which can be selected as needed, and its shape is not specifically limited, such as wire or sheet. The welding temperature is 800-1200℃, preferably 1000℃, and the welding equipment is a vacuum furnace. Of course, other types of solder can also be selected, such as gold, gold-nickel alloy, Kovar alloy, silver-copper-nickel alloy, etc.

[0109] It should be noted that the welding processes of the first welding layer 61 and the second welding layer 62 can be implemented separately or together.

[0110] The electrode connection structure and method of this embodiment, by setting a second gap, provides a buffer space during the expansion of the pre-fixed section when welding the electrode rod section to the inner hole and the smooth hole section to the connector. This reduces cracking at the threaded connection caused by the different thermal expansion coefficients of different materials, ensuring good electrical conductivity. Furthermore, setting the width of the second gap to 0.1-3mm not only avoids cracking due to thermal expansion but also ensures uniform heat conduction.

[0111] Example 3

[0112] like Figure 4 As shown, the lead electrode connection structure and connection method in this embodiment are a further improvement on Embodiment 1, the difference being:

[0113] The lead-out electrode 4 forms an electrode tube segment 41 and an electrode rod segment 42. An aperture segment 411 and a pre-fixed segment 412 are located within the electrode tube segment 41. The electrode tube segment 41 has an inner hole 413, the opening end of which is away from the aperture segment 411. The inner hole 413 extends at least to the entire length of the pre-fixed segment 412. Preferably, the inner hole 413 extends 1 mm below the bottom of the pre-fixed segment 412.

[0114] Place the third solder at the end of the electrode tube segment 41 away from the aperture segment, and then place the electrode rod segment 42 on top of the third solder.

[0115] A third solder is used to weld the electrode rod segment 42 and the end of the electrode tube segment 41 to form a third solder layer 63. The welding conditions can be selected based on the materials used. In this embodiment, the third solder is a gold-nickel alloy, the proportion of which can be selected as needed, and its shape is not specifically limited, such as wire or sheet. The welding temperature is 800-1200℃, preferably 1000℃. The welding equipment is a vacuum furnace. Of course, other types of solder can also be selected, such as gold, gold-nickel alloy, Kovar alloy, silver-copper-nickel alloy, etc.

[0116] In one alternative embodiment, a connecting strip 421 is formed at the end of the electrode rod segment 42. The length of the connecting strip 421 is less than the length of the inner hole 413. After the third solder is placed, the connecting strip 421 is inserted into the inner hole 413. In this embodiment, the shape of the connecting strip 421 is not specifically limited, but it is preferably tightly engaged with the inner hole 413, and its length is preferably such that the end of the connecting strip 421 is located above the pre-fixed segment 412.

[0117] It should be noted that the welding processes of the first welding layer 61 and the third welding layer 63 can be implemented separately or together.

[0118] The lead-out electrode connection structure and method of this embodiment, by designing the lead-out electrode as an electrode tube segment and an electrode rod segment, avoids cracking due to different coefficients of thermal expansion during welding due to the first gap. The ends of the electrode tube segment and the electrode rod segment are directly welded together, with the inner hole serving as a buffer space during welding. Simultaneously, the connection between the electrode rod segment and the electrode tube segment is robust and will not wobble. Furthermore, by providing a connecting strip, which is inserted into the inner hole before welding, the connection strength between the electrode tube segment and the electrode rod segment is further guaranteed.

[0119] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, any changes or modifications made by those skilled in the art based on the ideas of this application, and on the specific implementation methods and application scope of this application, are all within the scope of protection of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A ceramic heating plate lead-out electrode connection structure, comprising a connector embedded in a ceramic substrate, lead-out electrodes, and connection holes, characterized in that, The lead-out electrode includes an electrode tube segment and an electrode rod segment. A first gap is provided between the electrode tube segment and the connecting hole, and a second gap is provided between the electrode rod segment and the electrode tube segment. The electrode tube segment includes an optical aperture segment and a pre-fixed segment. The diameter of the pre-fixed segment is larger than the diameter of the optical aperture segment, and the optical aperture segment is located above and / or below the pre-fixed segment. The electrode tube segment and the connector form a first weld layer, and the electrode rod segment and the bottom of the electrode tube segment form a second weld layer.

2. The connection structure according to claim 1, characterized in that, The welding layer is one of gold, gold-nickel alloy, silver-copper-nickel alloy and Kovar alloy, the electrode rod section and the electrode tube section are both made of pure nickel, and the ceramic substrate is made of aluminum nitride.

3. A ceramic heating plate lead-out electrode connection structure, comprising a connector embedded in a ceramic substrate, lead-out electrodes, and connection holes, characterized in that, The lead-out electrode includes an electrode tube segment and an electrode rod segment. The electrode tube segment is provided with an inner hole, and the end of the electrode rod segment is provided with a protrusion. The protrusion and the inner hole form a convex-concave insertion structure. A first gap is provided between the electrode tube segment and the connecting hole, and a second gap is provided between the electrode rod segment and the inner hole of the electrode tube segment; The electrode tube segment includes an optical aperture segment and a pre-fixed segment, wherein the diameter of the pre-fixed segment is larger than the diameter of the optical aperture segment; The electrode tube segment and the joint form a first weld layer; The width of the first gap is 0.1-3mm, and the width of the second gap is 0.1-3mm.

4. The connection structure according to claim 3, characterized in that, The inner hole of the convex-concave insertion structure is a closed cavity.

5. The connection structure according to claim 3, characterized in that, According to design requirements, a third welding layer is provided around the electrode rod segment at a predetermined position along the length direction of the electrode rod segment.

6. The connection structure according to claim 5, characterized in that, The contact surfaces of the electrode tube segment and the electrode rod segment in the convex-concave plug-in structure are provided with the third welding layer.

7. The connection structure according to claim 5 or 6, characterized in that, The weld layer is one of gold, gold-nickel alloy, silver-copper-nickel alloy, and Kovar alloy.

8. The connection structure according to claim 3, characterized in that, Both the electrode rod segment and the electrode tube segment are made of pure nickel, and the ceramic matrix is ​​made of aluminum nitride.

9. The connection structure according to claim 3, characterized in that, A connecting strip is formed at the end of the electrode rod segment, and the connecting strip is inserted into the inner hole.

10. The connection structure according to claim 3, characterized in that, The difference in expansion coefficient between the substrate and the lead-out electrode is 8.6–14 ppm / K.

11. The connection structure according to claim 3, characterized in that, A ceramic composite powder coating with a void ratio of 30% to 60% is sprayed onto the interface between the connecting hole and the lead-out electrode.

12. The connection structure according to claim 11, characterized in that, The ceramic composite powder mainly consists of two or more of the following: alumina, zirconium oxide, calcium oxide, silicon oxide, barium oxide, lithium oxide, and boron oxide. The particle size of the alumina and zirconium oxide is 0.1–2 μm, the mass ratio of alumina to zirconium oxide is 0.25–4, and the mass of other oxides is less than 50% of the total mass.

13. The connection structure according to claim 3, characterized in that, A circular groove is opened at the bottom of the external thread of the electrode tube section, and a circular surface is machined at the tip of the internal thread of the connecting hole. A gap of about 0.05-0.5mm is pre-set at the contact point between the two.

14. A connection method for the ceramic heating plate lead-out electrode connection structure according to any one of claims 1-3, characterized in that, include: The connector is provided on the ceramic heating plate; The connecting hole is configured as a light hole portion and a pre-fixed hole portion; the lead-out electrode is configured as an electrode tube segment and an electrode rod segment; The electrode tube segment is configured as an optical aperture segment and a pre-fixed segment; A first solder is placed on the surface of the connector inside the connection hole. The electrode tube segment is screwed into the connection hole. The optical aperture segment presses against the connector inside the connection hole. The diameter of the optical aperture segment is smaller than the diameter of the optical aperture portion of the connection hole to form a first gap. The end of the optical aperture segment is welded to the connector to form a first weld layer. The electrode rod segment is inserted into the electrode tube segment, forming a second gap between the electrode rod segment and the electrode tube segment.

15. The connection method according to claim 14, characterized in that, An inner hole is provided in the electrode tube segment, the depth of which is at least to the entire length of the pre-fixed hole. A protrusion is provided at the end of the electrode rod segment, and the protrusion at the end of the electrode rod segment is inserted into the inner hole to form a closed cavity in the inner hole.

16. The connection method according to claim 15, characterized in that, According to design requirements, a third welding layer is provided around the electrode rod segment at a predetermined position along the length direction of the electrode rod segment. When the protrusion at the end of the electrode rod segment is inserted into the inner hole, the third welding layer is formed at the contact surface between the electrode tube segment and the electrode rod segment.

17. The connection method according to claim 14, characterized in that, The welding conditions for forming the weld layer are: vacuum welding, and the solder is one of gold, gold-nickel alloy, Kovar alloy, and silver-copper-nickel alloy.

18. The connection method according to claim 14, characterized in that, The ceramic heating plate mainly consists of heating elements and an electrode mesh. The heating elements and the electrode mesh are pre-embedded in an aluminum nitride ceramic plate. After hot pressing and sintering, the ceramic heating plate and the lead-out electrode are brazed together. Then, the heating components and radio frequency electrodes inside the ceramic heating plate are connected to an external power source through the electrode connector to form a circuit.

19. The connection method according to claim 14, characterized in that, Alumina powder, zirconium oxide powder, and silicon oxide powder are ball-milled in a certain proportion using ethanol as a medium, and then sprayed onto the connection positions of the connecting holes and the lead-out electrodes. The ethanol is evaporated by drying, and the entire component is placed in a vacuum brazing furnace for brazing. The brazing temperature is 800-1200℃, the vacuum degree is 10⁻⁴ mmHg, and the holding time is 10-180 min. After heating, the component is cooled to room temperature under an inert atmosphere.

20. The connection method according to claim 14, characterized in that, The electrode tube segment is provided with an external thread. The external thread of the electrode tube segment is specially designed with a circular groove at the bottom end of the external thread and a circular surface machined at the tip of the internal thread of the connecting hole. There is a gap of about 0.05-0.5mm at the contact point between the two to ensure that the welding wire spool can be screwed into the thread of the connecting hole when it is at the bottom end of the thread of the pre-fixed section of the electrode tube segment. Then, vacuum brazing is performed to further fix the electrode tube segment and the ceramic connecting hole together by melting the welding wire.

21. The connection method according to claim 14, characterized in that, By winding welding wire around the threaded bottom end of the pre-fixed section of the electrode tube and screwing it into the pre-fixed hole section of the connecting hole, the connecting hole and the pre-fixed section of the electrode tube are tightly connected by brazing after the welding wire melts.

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