Chemical vapor deposition equipment, heating disc and method for forming coating

Abstract

The invention discloses chemical vapor deposition equipment, a heating disc and a method for forming a coating. The heating disc comprises a heating disc body and a rare earth metal layer, the surface of the heating disc body is covered with the rare earth metal layer, and the porosity of the rare earth metal layer is smaller than 0.1%. According to the invention, the rare earth metal layer with the porosity less than 0.1% is arranged on the surface of the heating plate body, so that the plasma resistance of the heating plate is improved; the thermal expansion coefficient difference between the rare earth metal layer and the surface of the metal heating plate body is small, and the coating on the surface of the heating plate can be prevented from peeling off and cracking in a high-temperature environment. Furthermore, a corrosion-resistant coating is grown on the surface of the rare earth metal layer, the corrosion-resistant coating is at least one of oxide, fluoride or oxyfluoride of rare earth metal, the corrosion resistance of the heating plate can be further improved, the service life of the heating plate can be further prolonged, and when the corrosion-resistant coating goes wrong and needs to be replaced and renovated, the renovation cost is lower.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a chemical vapor deposition device, a heating plate and a method for forming a coating. Background Art

[0002] Chemical vapor deposition (CVD) equipment often needs to heat a wafer or a chamber or maintain the temperature required for the deposition reaction when performing a deposition reaction, so CVD equipment is usually equipped with a heating plate for heating the wafer.

[0003] In the prior art, aluminum alloy is often used as a manufacturing material for heating disks in CVD equipment due to its advantages such as high thermal conductivity and low cost. However, in the chemical vapor deposition process, when the aluminum alloy heating disk is exposed to a fluorine-containing plasma environment, the surface of the heating disk is easily fluorinated to form an aluminum fluoride layer. Currently, the equipment requires dozens of hours of fluorination to stabilize the fluorination depth of the heating disk surface, which is time-consuming and costly, resulting in the lack of market competitiveness of the equipment.

[0004] Therefore, there is an urgent need in the art for a novel heating plate with excellent corrosion resistance. Summary of the invention

[0005] The object of the present invention is to provide a chemical vapor deposition device, a heating disk and a method for forming a coating on the surface thereof, so as to improve the anti-plasma corrosion performance of the heating disk.

[0006] In order to achieve the above object, the present invention first provides a heating plate, comprising:

[0007] Heating plate body;

[0008] A rare earth metal layer covers the surface of the heating plate body, and the porosity of the rare earth metal layer is less than 0.1%.

[0009] Optionally, the rare earth metal layer has a thickness of 5 μm to 20 μm.

[0010] Optionally, the heating plate further comprises: a corrosion-resistant coating located on the surface of the rare earth metal layer.

[0011] Optionally, the porosity of the corrosion-resistant coating is less than 0.1%.

[0012] Optionally, the corrosion-resistant coating has a thickness of 0.05 μm to 2 μm.

[0013] Optionally, the material of the corrosion-resistant coating is at least one of oxides, fluorides or oxyfluorides of rare earth metals.

[0014] Optionally, in the rare earth metal layer and the corrosion-resistant coating, the rare earth metal is selected from at least one of Y (yttrium), Sc (scandium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb (ytterbium) or Lu (lutetium).

[0015] Optionally, the material of the surface of the heating plate body includes metal elements.

[0016] Optionally, the material of the surface of the heating plate body includes at least one of aluminum, aluminum alloy and aluminum nitride.

[0017] Optionally, the heating plate body is provided with a fluid groove recessed in its upper surface, and the fluid groove is used to transmit a heat transfer medium to improve the temperature uniformity of a wafer placed above the heating plate.

[0018] Optionally, the rare earth metal layer covers the bottom and sidewalls of the fluid trench.

[0019] Optionally, the depth-to-width ratio of the fluid groove is 0.5:1 to 5:1.

[0020] Another aspect of the present invention provides a chemical vapor deposition device, comprising:

[0021] Reaction chamber;

[0022] As the heating plate mentioned above, the heating plate is located in the reaction chamber and is used for carrying and heating the wafer.

[0023] Another aspect of the present invention provides a method for forming a coating on the surface of a heating plate body, comprising the following steps:

[0024] Providing a heating plate body;

[0025] A rare earth metal layer is formed on the surface of the heating plate body, and the porosity of the rare earth metal layer is less than 0.1%.

[0026] Optionally, the preparation method further comprises: forming a corrosion-resistant coating on the surface of the rare earth metal layer, wherein the corrosion-resistant coating is at least one of an oxide, a fluoride or an oxyfluoride of the rare earth metal.

[0027] Optionally, the rare earth metal layer and the corrosion-resistant coating are formed by physical vapor deposition.

[0028] Optionally, the deposition temperature of the rare earth metal layer and the corrosion-resistant coating is 250°C to 450°C.

[0029] Optionally, after the rare earth metal layer is formed, the corrosion-resistant coating is deposited on the surface of the rare earth metal layer by using the rare earth metal as a target and introducing at least one of oxygen and fluorine-containing gases.

[0030] Optionally, after the rare earth metal layer is formed, any one of oxygen, fluorine-containing gas or a mixture of the two is introduced to cause oxidation, fluorination or fluorine oxidation on the surface of the rare earth metal layer to form a corrosion-resistant coating on the surface of the rare earth metal layer.

[0031] Optionally, the fluorine-containing gas is a fluorocarbon gas or a hydrocarbon fluorine gas.

[0032] Compared with the prior art, the beneficial effects of the technical solution of the present invention include at least:

[0033] (1) The present invention provides a heating plate protective coating with excellent corrosion resistance, high thermal conductivity and resistance to peeling and cracking under high temperature operation. Specifically, the protective coating is a rare earth metal layer with a porosity of less than 0.1%. The coating formed by the rare earth metal used in the present invention has strong anti-plasma properties. It is arranged on the surface of the heating plate body to improve the resistance of the heating plate to plasma erosion; at the same time, the difference in thermal expansion coefficient between the rare earth metal layer and the surface of the metal heating plate body is small, which can prevent the rare earth metal layer on the surface of the heating plate, especially the rare earth metal layer in the irregular surface area, from peeling and cracking under high temperature working environment, causing the heating plate to lose its protective function; in addition, the rare earth metal layer has excellent thermal conductivity, which can improve the temperature distribution uniformity and thermal conductivity of the heating plate.

[0034] (2) The present invention further provides a corrosion-resistant coating on the surface of the rare earth metal layer. The corrosion-resistant coating is at least one of the oxide, fluoride or oxyfluoride of the rare earth metal, which has stronger resistance to plasma erosion than the rare earth metal layer, can further improve the corrosion resistance of the heating plate, and is beneficial to prolonging the service life; in addition, the thickness of the corrosion-resistant coating is 0.05μm to 2μm. The design of this thickness range will not affect the heat transfer effect of the heating plate while ensuring the corrosion resistance, and when the corrosion-resistant coating has problems and needs to be replaced and refurbished, the renovation cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of a chemical vapor deposition device of the present invention.

[0036] Figure 2 It is a schematic structural diagram of a heating plate according to an embodiment of the present invention.

[0037] Figure 3 FIG. 1 is a cross-sectional schematic diagram of a heating plate body according to an embodiment of the present invention.

[0038] Figure 4 It is a cross-sectional schematic diagram of a heating plate body after a rare earth metal layer is formed on the surface of the heating plate body according to an embodiment of the present invention. Figures 5 and 6 Schematic diagram of the partial structure of the heating plate according to different embodiments of the present invention.

[0039] Figure 7 FIG. 4 is a cross-sectional schematic diagram of a heating plate according to another embodiment of the present invention.

[0040] Figures 8 to 9 Flowchart of a method for forming a coating on the surface of a heating plate body provided in different embodiments of the present invention.

[0041] Figure ID:

[0042] Reaction chamber 1; heating plate 2; support rod 3; shower head 4; heating plate body 21; fluid groove 211; air inlet 212; recovery hole 213; rare earth metal layer 22; corrosion-resistant coating 23. DETAILED DESCRIPTION

[0043] In order to solve the above technical problems, the embodiments of the present invention provide a plasma corrosion resistant heating disk and a preparation method thereof, as well as an embodiment of the heating disk obtained by the method, and an embodiment of a chemical vapor deposition device including the heating disk.

[0044] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0045] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0047] As described in the background technology, the surface of the heating plate made of aluminum alloy is easily fluorinated, and it takes a long time for the fluorination depth to stabilize. In order to isolate the heating plate from the fluorine-containing environment, one solution is to use atmospheric plasma spraying of rare earth metal fluoride, oxide or oxyfluoride coating on the aluminum alloy surface of the heating plate, but the coating prepared by the atmospheric plasma spraying process contains cracks and has a porosity greater than 0.5%, so that the fluorine-containing plasma is easy to penetrate along the gaps or holes and react with the aluminum heating plate substrate to produce aluminum fluoride; another solution is to use evaporation coating technology to deposit a 5μm to 10μm thick aluminum fluoride coating on the surface of the heating plate, but the aluminum fluoride coating prepared by this process is not dense and has poor bonding strength. At the working temperature (250℃~450℃), the aluminum fluoride coating on the surface of the heating plate, especially the aluminum fluoride coating at the irregular surface area (such as the chamfer of the groove on the surface of the heating plate for dispersing gas), is easy to crack and peel off, resulting in the exposure of the heating plate substrate and loss of protection.

[0048] In summary, whether it is rare earth metal fluoride, oxide or oxyfluoride coating sprayed by atmospheric plasma, or aluminum fluoride formed by evaporation coating technology, it is difficult to provide good protection for the heating plate, so that some parts of the heating plate are still prone to contact with fluorine, thereby consuming the fluorine content and causing unstable film deposition rate.

[0049] In order to solve the above technical problems, the present invention finally proposes a new heating plate, the surface of which is provided with a rare earth metal layer with a porosity of less than 0.1%. The rare earth metal layer has high density and strong bonding ability, and can well protect the heating plate and prevent the heating plate from contacting the fluorine-containing environment. Therefore, the heating plate is not easy to consume the fluorine-containing environment, which is beneficial to improve the stability of the fluorine content in the film growth environment, and further to improve the stability of the film growth. In addition, the rare earth metal layer has good thermal conductivity, which can effectively improve the anti-plasma erosion performance and temperature distribution uniformity of the heating plate. The following is a detailed description:

[0050] The heating plate provided by the invention can be used in chemical vapor deposition equipment.

[0051] Figure 1 A chemical vapor deposition device 100 provided in one embodiment of the present invention includes:

[0052] A reaction chamber 1 forms a space for chemical reactions; a heating plate 2 is disposed in the reaction chamber 1 and is used to carry and heat wafers; a support rod 3 is located below the heater 2 and is used to support the heater 2 and enable the heater 2 to rise, fall and rotate in the chamber 1; a shower head 4 is located at the top of the reaction chamber 1, and process gas can enter the chamber 1 through the shower head 4; and an exhaust port 5 is used to discharge the reacted gas from the inside of the reaction chamber 1.

[0053] It should be understood that the chemical vapor deposition equipment in the present invention can be various types of chemical vapor deposition equipment including a heating plate. Figure 1 It is merely exemplary and may include fewer or more constituent elements, or the arrangement of the constituent elements may be the same as or different from that shown in the drawings.

[0054] The following is attached Figure 2 To Attachment Figure 7 The heating plate 2 of the present invention is described in detail:

[0055] Figures 2 to 5 The schematic diagram of the structure of a heating plate 2 with a fluid groove 211 provided in one embodiment of the present invention, the heating plate 2 comprises:

[0056] The heating plate body 21, the fluid groove 211 is recessed in the upper surface of the heating plate body 21, and the fluid groove 211 is used to transmit the heat transfer medium to improve the temperature uniformity of the wafer placed on the heating plate 2;

[0057] The rare earth metal layer 22 covers the surface of the heating plate body 21 .

[0058] It should be noted that the surface of the heating plate body 21 of the present invention at least includes the upper surface and the circumferential side surface of the heating plate body 21. In this embodiment, the upper surface of the heating plate body 21 also includes the surface of the fluid groove 211, such as Figure 4 As shown, the rare earth metal layer 22 covers the bottom and sidewalls of the fluid trench 211 .

[0059] In the heating plate 2 provided in this embodiment, the material of the surface of the heating plate body 21 includes metal elements. Metal has good thermal conductivity, which is conducive to improving the thermal efficiency of the heating plate 2. As an example, the material of the surface of the heating plate body 21 includes at least one of aluminum, aluminum alloy and aluminum nitride (AlN). In some embodiments, the material of the heating plate body 21 includes metal or metal alloy, including at least one of aluminum, aluminum alloy and aluminum nitride (AlN).

[0060] In the rare earth metal layer 22, the rare earth metal is selected from at least one of Y (yttrium), Sc (scandium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb (ytterbium) or Lu (lutetium). Compared with the aluminum fluoride protective coating commonly used in the prior art, the rare earth metal layer 22 is provided on the surface of the heating plate body 21 in the present invention, which includes the following functions and advantages:

[0061] (1) The rare earth metal layer 22 has strong anti-plasma properties. Covering the rare earth metal layer 22 on the surface of the heating plate body 21 can make the heating plate 2 have excellent resistance to plasma erosion. In particular, when the rare earth metal layer 22 is exposed to a fluorine-containing plasma environment, the rare earth metal on its surface will react with the fluorine plasma to form a rare earth metal fluoride with stronger corrosion resistance, further improving the corrosion resistance of the heating plate 2. It can not only avoid the uneven temperature distribution caused by the corrosion of the heating plate 2, which in turn affects the uniformity of the thin film deposited on the wafer surface, but also extend the service life of the heating plate 2.

[0062] (2) The difference in thermal expansion coefficient between the rare earth metal layer 22 and the surface of the metal heating plate body is small, which can prevent the rare earth metal layer 22 from peeling off and cracking in a high-temperature working environment, causing the heating plate 2 to lose its protective function.

[0063] (3) The rare earth metal layer 22 has excellent thermal conductivity, which ensures the uniformity of temperature distribution and thermal conductivity of the heating plate 2.

[0064] Furthermore, the porosity of the rare earth metal layer 22 is less than 0.1%, and the purpose is to make the rare earth metal layer 22 have sufficient density to prevent the coating from being damaged by corrosive plasma or even penetrating to the surface of the heating plate 2, causing the film to rupture and lose its protective function. The rare earth metal coating 22 has a strong protective ability for the heating plate 2, so that the material of the heating plate 2 is not easy to contact the fluorine-containing gas in the thin film process during the thin film process, and the heating plate 2 does not consume the fluorine-containing gas, which is beneficial to the stability of the fluorine-containing gas in the thin film process and to improve the stability of the thin film growth.

[0065] In some embodiments, the thickness of the rare earth metal layer 22 is 5 μm to 20 μm. It is understood that if the rare earth metal layer 22 is too thin, it cannot play a good role in resisting plasma erosion; if it is too thick, it will cause the heating disk 2 to have poor heat transfer effect and high cost. Therefore, this embodiment determines the appropriate film thickness range of the rare earth metal layer 22 based on the actual application coating thickness range of the heating disk 2 in the chemical vapor deposition equipment, taking into account heat transfer effect, cost, etc.

[0066] The heating plate 2 provided in this embodiment further includes an air inlet 212 and a recovery hole 213. The locations of the air inlet 212 and the recovery hole 213 are not limited to Figure 2As shown, in other embodiments, it can be set at other positions on the upper surface of the heating plate 2. The air inlet 212 and the recovery hole 213 are respectively connected to the fluid groove 211, and the air inlet 212 provides a heat transfer medium, which is transmitted to the recovery hole 213 through the fluid groove 211 to achieve the circulation of the heat transfer medium, so as to improve the temperature uniformity of the wafer placed above the heating plate 2. Commonly used heat transfer media include helium, neon, argon and hydrogen. In some embodiments, the recovery hole 213 is connected to a recovery component for recycling and reusing the heat transfer medium; in other embodiments, the heat transfer medium is directly discharged after passing through the recovery hole 213.

[0067] As an example, the depth of the fluid groove 211 is 1 mm to 2 mm, the width is 1 mm to 2 mm, and the depth-to-width ratio of the fluid groove 211 is 0.5:1 to 5:1. Figure 5 As shown, it can be understood that if the aspect ratio is too large, it is difficult for the rare earth metal layer 22 to completely cover the bottom and side walls of the fluid groove 211 during preparation, especially the bottom corners of the fluid groove 211 are difficult to be covered by the rare earth metal layer 22, resulting in the surface base of the heating disk 2 still being partially exposed to the corrosive plasma environment, which is easily corroded and affects the uniformity of the temperature distribution of the heating disk 2; however, if the aspect ratio of the fluid groove 211 is too small, such as the depth is too shallow, the effect of transmitting the heat transfer medium to improve the uniformity of the temperature distribution will be poor.

[0068] like Figure 6 As shown, in order to further improve the plasma erosion resistance of the heating plate 2 , the present invention further forms a corrosion-resistant coating 23 on the surface of the rare earth metal layer 22 .

[0069] In the heating plate 2 provided in this embodiment, the corrosion-resistant coating 23 and the rare earth metal layer 22 both have strong corrosion resistance. When working in a high-temperature environment, even if the corrosion-resistant coating 23 has tiny cracks, the rare earth metal layer 22 still has anti-plasma erosion performance, avoiding the problem of the surface of the heating plate body 21 contacting with the corrosive plasma (such as fluorine-containing plasma) to form a byproduct layer with uneven thickness, thereby solving the problem of uneven temperature distribution of the heating plate 2 caused by the byproduct layer.

[0070] In some embodiments, the corrosion-resistant coating 23 has stronger plasma erosion resistance than the rare earth metal layer 22. As an example, the corrosion-resistant coating 23 is made of at least one of oxides, fluorides or oxyfluorides of rare earth metals, and the rare earth metal is selected from at least one of Y, Sc, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

[0071] In some embodiments, the thickness of the corrosion-resistant coating 23 is less than the thickness of the rare earth metal layer 22. It is understandable that if the corrosion-resistant coating 23 is too thick, there will be problems such as the coating being easy to crack and peel off in a high-temperature working environment, resulting in poor heat transfer effect of the heating disk 2; if it is too thin, the corrosive plasma will diffuse into the rare earth metal layer 22, and it will not play a role in enhancing the resistance to plasma erosion. As an example, the thickness of the corrosion-resistant coating 23 is 0.05μm to 2μm. The corrosion-resistant coating 23 within this thickness range not only has strong resistance to plasma erosion, but also does not cause problems such as poor heat transfer effect of the heating disk. More importantly, when the corrosion-resistant coating 23 has problems and needs to be replaced and refurbished, the cost is lower. Specifically, the corrosion-resistant coating 23 can be removed by laser, plasma etching or ion beam etching, and the corrosion-resistant coating 23 can be re-prepared.

[0072] In some embodiments, in order to improve the plasma erosion resistance of the corrosion-resistant coating 23, the corrosion-resistant coating 23 needs to have sufficient density. For example, the porosity of the corrosion-resistant coating 23 may be less than 0.1%.

[0073] like Figure 7 As shown, it should be understood that although the heating plate 2 described above has the fluid groove 211, the heating plate 2 without the fluid groove 211 and including the rare earth metal layer 22 or the rare earth metal layer 22 and the corrosion-resistant coating 23 described in the present invention is also within the protection scope of the present invention.

[0074] Next, the method of forming a coating on the surface of the heating plate body 21 of the present invention is described.

[0075] The process of forming a coating on the surface of the heating plate body 21 according to an embodiment of the present invention includes the following steps:

[0076] Step (1), providing a heating plate body 21.

[0077] The material of the surface of the heating plate body 21 includes metal elements. As an example, the material of the surface of the heating plate body 21 includes at least one of aluminum, aluminum alloy and aluminum nitride (AlN).

[0078] Step (2), forming a rare earth metal layer 22.

[0079] A rare earth metal layer 22 having a porosity of less than 0.1% is formed on the surface of the heating plate body 21, and the preparation method of the rare earth metal layer 22 includes a physical vapor deposition process (PVD). In the rare earth metal layer 22, the rare earth metal is selected from at least one of Y, Sc, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

[0080] In this embodiment, the rare earth metal layer 22 is formed by deposition using a PVD process. Specifically, the rare earth metal is used as a target material, Ar is introduced, and the rare earth metal layer 22 is formed by sputtering deposition under the condition of a deposition temperature of 250°C to 450°C. Among them, the advantage of the deposition temperature (250°C to 450°C) designed by the present invention is that the rare earth metal layer 22 formed by deposition at such a high temperature is conducive to eliminating the internal stress of the coating and preventing the coating from cracking when used at a high temperature later. However, the deposition temperature cannot be too high. When the temperature is too high, the heating plate 2 is deformed due to the operating temperature approaching or even exceeding the melting point of the heating plate material (such as the melting point of pure aluminum is 660°C), thereby affecting the process consistency of the entire wafer and even causing the failure of the entire process result.

[0081] In another embodiment of the present invention, the process of forming a coating on the surface of the heating plate body 21 includes the following steps:

[0082] Step (1), providing a heating plate body 21.

[0083] The material of the surface of the heating plate body 21 includes metal elements. As an example, the material of the surface of the heating plate body 21 includes at least one of aluminum, aluminum alloy and aluminum nitride (AlN).

[0084] Step (2), forming a rare earth metal layer 22.

[0085] This embodiment adopts PVD technology to form a rare earth metal layer 22 with a porosity less than 0.1% on the surface of the heating plate body 21, and the deposition temperature is 250°C to 450°C.

[0086] Step (3), forming a corrosion-resistant coating 23.

[0087] A corrosion-resistant coating 23 having a porosity of less than 0.1% is further formed on the surface of the rare earth metal layer 22. The corrosion-resistant coating 23 is made of at least one of oxides, fluorides or oxyfluorides of rare earth metals, and the rare earth metal is selected from at least one of Y, Sc, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

[0088] In some embodiments, the method for forming the corrosion-resistant coating 23 includes: after forming the rare earth metal layer 22, continuing to use the PVD process, using the rare earth metal as the target, and introducing at least one of oxygen or fluorine-containing gas, with a deposition temperature of 250°C to 450°C, to deposit the corrosion-resistant coating 23 on the surface of the rare earth metal layer 22. In some other embodiments, the method for forming the corrosion-resistant coating 23 includes: after forming the rare earth metal layer 22, no rare earth metal target is provided, the chamber temperature is maintained at 250°C to 450°C, and any one of oxygen, fluorine-containing gas, or a mixture of the two is introduced, so that the surface of the rare earth metal layer 22 is oxidized, fluorinated, or fluorinated, thereby forming the corrosion-resistant coating 23 on the surface of the rare earth metal layer 22.

[0089] Optionally, the fluorine-containing gas is a fluorocarbon gas or a hydrocarbon fluorine gas. As an example, the fluorine-containing gas includes CF4, CHF3, CH2F2, etc.

[0090] In this embodiment, the rare earth metal layer 22 and the corrosion-resistant coating 23 are both grown in a physical vapor deposition chamber, without the need to open a chamber to replace equipment or replace the target material. This can greatly simplify the process flow, improve preparation efficiency, and also prevent the heating plate 2 from being contaminated during the switching process.

[0091] In some embodiments, in order to ensure the uniformity of the rare earth metal layer 22 and the corrosion-resistant coating 23 and the effectiveness of their protective effect, the rare earth metal layer 22 and the corrosion-resistant coating 23 are repaired according to the usage or regularly. Specifically, for the heating plate 2 including only the rare earth metal layer 22, when repairing, most of the rare earth metal layer 22 is removed by laser or other methods (retaining 5 μm thickness), and then the rare earth metal layer 22 is re-prepared to achieve the purpose of ensuring the uniformity and protective effect of the rare earth metal layer 22; for the heating plate 2 including the rare earth metal layer 22 and the corrosion-resistant coating 23, when repairing, optionally, the corrosion-resistant coating 23 is removed by laser or other methods, and then the corrosion-resistant coating 23 is re-prepared; or, after removing the corrosion-resistant coating 23 and most of the rare earth metal layer 22 (retaining 5 μm thickness) by laser or other methods, the rare earth metal layer 22 and the corrosion-resistant coating 23 are re-prepared in sequence to achieve the purpose of ensuring the uniformity and protective effect of the rare earth metal layer 22 and the corrosion-resistant coating 23.

[0092] In summary, the present invention improves the resistance of the heating disk to plasma erosion by providing a rare earth metal layer with a porosity of less than 0.1% on the surface of the heating disk body; the difference in thermal expansion coefficient between the rare earth metal layer and the surface of the metal heating disk body is small, which can prevent the protective coating on the surface of the heating disk from peeling off and cracking in a high-temperature working environment, causing the heating disk to lose its protective function. Furthermore, the present invention also grows a corrosion-resistant coating on the surface of the rare earth metal layer, and the corrosion-resistant coating is at least one of an oxide, fluoride or oxyfluoride of a rare earth metal, which can further improve the corrosion resistance of the heating disk and extend its service life. When the corrosion-resistant coating has problems and needs to be replaced and refurbished, the renovation cost is lower.

[0093] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A heating plate, characterized in that: include: Heating plate body; A rare earth metal layer covers the surface of the heating plate body, and the porosity of the rare earth metal layer is less than 0.1%.

2. The heating plate according to claim 1, characterized in that The rare earth metal layer has a thickness of 5 μm to 20 μm.

3. The heating plate according to claim 1, characterized in that The heating plate further comprises: a corrosion-resistant coating located on the surface of the rare earth metal layer.

4. The heating plate according to claim 3, characterized in that The porosity of the corrosion-resistant coating is less than 0.1%.

5. The heating plate according to claim 3, characterized in that: The thickness of the corrosion-resistant coating is 0.05 μm to 2 μm.

6. The heating plate according to claim 3, characterized in that: The material of the corrosion-resistant coating is at least one of oxides, fluorides or oxyfluorides of rare earth metals.

7. The heating plate according to claim 6, characterized in that In the rare earth metal layer and the corrosion-resistant coating, the rare earth metal is selected from at least one of Y, Sc, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

8. The heating plate according to claim 1, characterized in that The material of the surface of the heating plate body includes metal elements.

9. The heating plate according to claim 8, characterized in that The material of the surface of the heating plate body includes at least one of aluminum, aluminum alloy and aluminum nitride.

10. The heating plate according to any one of claims 1 to 9, characterized in that: The heating plate body is provided with a fluid groove recessed in its upper surface, and the fluid groove is used to transmit a heat transfer medium to improve the temperature uniformity of the wafer placed above the heating plate.

11. The heating plate according to claim 10, characterized in that The rare earth metal layer covers the bottom and sidewalls of the fluid trench.

12. The heating plate according to claim 10, characterized in that The depth-to-width ratio of the fluid groove is 0.5:1 to 5:

1.

13. A chemical vapor deposition device, characterized in that: include: Reaction chamber; The heating plate as described in any one of claims 1-12 is located in the reaction chamber and is used to carry and heat the wafer.

14. A method for forming a coating on the surface of a heating plate body, characterized in that: The following steps are involved: Providing a heating plate body; A rare earth metal layer is formed on the surface of the heating plate body, and the porosity of the rare earth metal layer is less than 0.1%.

15. The method for forming a coating on the surface of a heating plate body according to claim 14, characterized in that: Also includes: A corrosion-resistant coating is formed on the surface of the rare earth metal layer, and the corrosion-resistant coating is at least one of oxides, fluorides or oxyfluorides of the rare earth metal.

16. The method for forming a coating on the surface of a heating plate body according to claim 15, characterized in that: The rare earth metal layer and the corrosion-resistant coating are formed by physical vapor deposition.

17. The method for forming a coating on the surface of a heating plate body according to claim 16, characterized in that: The deposition temperature of the rare earth metal layer and the corrosion-resistant coating is 250°C to 450°C.

18. The method for forming a coating on the surface of a heating plate body according to claim 15, characterized in that: After the rare earth metal layer is formed, the rare earth metal is used as a target material and at least one of oxygen and fluorine-containing gas is introduced to deposit the corrosion-resistant coating on the surface of the rare earth metal layer.

19. The method for forming a coating on the surface of a heating plate body according to claim 15, characterized in that: After the rare earth metal layer is formed, any one of oxygen, fluorine-containing gas or a mixed gas of the two is introduced to cause oxidation, fluorination or fluorine oxidation on the surface of the rare earth metal layer to form a corrosion-resistant coating on the surface of the rare earth metal layer.

20. The method for forming a coating on the surface of a heating plate body according to claim 18 or 19, characterized in that: The fluorine-containing gas is a fluorocarbon gas or a hydrocarbon-fluorine gas.

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