CN115595552B

CN115595552B - Silicon carbide ring for plasma etching equipment and forming process of silicon carbide ring

Info

Publication number: CN115595552B
Application number: CN202211617858.3A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: New Meguiar Suzhou Semiconductor Technology Co ltd
Current assignee: New Meguiar Suzhou Semiconductor Technology Co ltd
Priority date: 2022-12-16
Filing date: 2022-12-16
Publication date: 2023-04-11
Anticipated expiration: 2042-12-16
Also published as: CN115595552A

Abstract

The invention discloses a silicon carbide ring for plasma etching equipment and a forming process of the silicon carbide ring. The molding process comprises the following steps: s1: installing a substrate in a reaction chamber of chemical vapor deposition equipment; the heating device on the furnace body surrounds the substrate, the substrate is an annular body with a groove, and the groove extends from the outer ring surface of the annular body to the inner ring surface; s2: vacuumizing the reaction chamber; s3: operating a heating device to heat the reaction chamber to a preset temperature; s4: introducing reaction gas including carrier gas, diluent gas and precursor containing carbon element and silicon element into the reaction chamber; decomposing and depositing the reaction gas on the surface of the substrate at a preset temperature to form a silicon carbide layer; s5: closing the heating device, cooling and taking out the substrate deposited with the silicon carbide layer; s6: and stripping the substrate to obtain the silicon carbide ring. The present disclosure improves the thickness and texture property uniformity of a substrate surface deposited silicon carbide film in the radial direction.

Description

Silicon carbide ring for plasma etching equipment and forming process of silicon carbide ring

Technical Field

The invention relates to the technical field of chemical vapor deposition, in particular to a silicon carbide ring for plasma etching equipment and a forming process of the silicon carbide ring.

Background

Silicon carbide (SiC) material, as an excellent third-generation semiconductor material, has advantages of high thermal conductivity, plasma etching resistance, oxidation resistance, wear resistance, corrosion resistance, high-temperature stability, and the like, and particularly has excellent characteristics of hardly causing particle contamination in a plasma etching manufacturing process. Parts prepared by using silicon carbide materials, such as Top Edge Ring and Focus Ring in an etching machine, electrodes, a base used by chemical vapor deposition reaction equipment and the like, effectively improve the service cycle and the quality of the parts, and become one of important Edge tools for successful volume production and yield guarantee in the field of semiconductors.

In the coming years, with the continuous development and progress of semiconductor manufacturing processes, such as narrower and narrower device gate widths and deeper etching holes, these processes all depend on the performance improvement of semiconductor components. The silicon carbide part material is suitable for the process improvement of the plasma etching link of the integrated circuit due to excellent thermal conductivity, plasma etching resistance and the like, and mainly shows the improvement of the service life of the part and the reduction of polluting particles of the part. The currently mainstream silicon carbide component preparation technology is a chemical vapor deposition technology, i.e., a precursor is utilized to pyrolyze and react at a high temperature to obtain C/Si atoms, and a silicon carbide material is deposited on a substrate, core parameters of the technology mainly include gas distribution, temperature and pressure, and the control of the parameters can affect the structure and performance of the silicon carbide deposition material. Wherein, the substrate surface is the position where the deposition of C/Si atoms directly occurs, and the uniform control of the substrate temperature is particularly critical.

At present, a common substrate of a chemical vapor deposition silicon carbide part is a high-purity graphite material, taking the preparation of a SiC Edge Ring part for plasma etching as an example, the selected graphite substrate is generally in the form of a large-size circular Ring with the outer diameter of 290-400mm, and is arranged in a furnace body in a multi-sheet stacking manner, and the substrate and the deposition environment are heated in a resistance heating manner. However, in the actual production process, it is found that the annular silicon carbide component grown in the above manner is used as Edge Ring in a plasma etching device, and the path of plasma is deviated, so that the etching is not uniform.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a silicon carbide ring for plasma etching equipment and a forming process of the silicon carbide ring, which can improve the temperature uniformity of the surface of a substrate in the radial direction and obtain the silicon carbide ring with uniform texture.

The first aspect of the present disclosure provides a molding process of a silicon carbide ring, including the steps of:

s1: installing a substrate in a reaction chamber of chemical vapor deposition equipment; the furnace body of the chemical vapor deposition equipment limits the reaction chamber, a heating device is arranged on the furnace body, the heating device surrounds the substrate, the substrate is an annular body with a groove, and the groove extends from the outer ring surface of the annular body to the inner ring surface of the annular body;

s2: vacuumizing the reaction chamber;

s3: operating the heating device to heat the reaction chamber to a preset temperature;

s4: introducing reaction gas into the reaction chamber, wherein the reaction gas comprises carrier gas, diluent gas and a precursor containing carbon element and silicon element; the reaction gas is decomposed and deposited on the surface of the substrate at the preset temperature to form a silicon carbide layer;

s5: when the silicon carbide layer deposited on the substrate meets the preset condition, closing the heating device, and taking out the substrate deposited with the silicon carbide layer after cooling;

s6: and stripping the substrate to obtain the silicon carbide ring.

Optionally, the annular body has a chamfered transition between an upper surface thereof and the outer annular surface and/or between a lower surface thereof and the outer annular surface.

Optionally, the cross-sectional shape of the groove is a conic parabolic curve.

Optionally, the substrate is made of a graphite material with ash content lower than 50ppm or a silicon carbide material with purity higher than 99.999%.

Optionally, the reaction chamber is evacuated to 0.1-0.01 Torr in step S2.

Optionally, the preset temperature in the step S3 is 1050 ℃ to 1600 ℃.

Optionally, step S4 includes: introducing methyltrichlorosilane serving as a precursor into the reaction chamber, wherein the flow rate is 6 SLPM-12 SLPM; introducing hydrogen as a carrier gas into the reaction chamber, wherein the flow rate is 40 SLPM-100 SLPM; and introducing nitrogen serving as diluent gas into the reaction chamber, wherein the flow rate is 3-40 LPM.

Optionally, after step S6, the method further includes: machining the silicon carbide ring to a target size.

Optionally, a rotating table and at least one rotating shaft are arranged in the reaction chamber, the rotating table is rotatably arranged on the bottom wall of the furnace body, the at least one rotating shaft is arranged close to the edge of the rotating table, and the substrate is mounted on the rotating shaft;

chemical vapor deposition equipment still includes revolving stage driving piece and rotation axis driving piece, to when the reaction chamber lets in reaction gas, revolving stage driving piece drive the revolving stage is rotatory for the furnace body, rotation axis driving piece drive the rotation axis for the revolving stage is rotatory, the direction of rotation of revolving stage with the direction of rotation axis is opposite.

The second aspect of the present disclosure provides a silicon carbide ring for a plasma etching apparatus, which is prepared by using the molding process of the silicon carbide ring according to the first aspect.

The implementation of the scheme has the following beneficial effects:

the present disclosure improves the thickness and texture property uniformity of a substrate surface deposited silicon carbide film in the radial direction. Specifically, by arranging the groove on the outer annular surface of the annular substrate, when the heating device surrounding the substrate heats, the groove structure can improve the temperature difference caused by the difference between the inner side and the outer side of the substrate and the spatial position of the heating device, improve the temperature uniformity of the surface of the substrate in the radial direction, and ensure that the carbon/silicon atoms on the surface of the substrate are deposited more uniformly. By designing the chamfer transition of the upper surface, the lower surface and the outer annular surface of the substrate, the influence of a chemical vapor deposition reaction boundary layer and nucleation and diffusion of carbon/silicon atoms to the inner side of the substrate, which are caused by the excessive thickness of the outer edge of the substrate, is reduced, the deposition uniformity of a silicon carbide material can be further improved, and the radial thickness difference of the silicon carbide layer is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a chemical vapor deposition apparatus provided by an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a structure of a substrate provided by an embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional view of a substrate provided by an embodiment of the present disclosure;

FIG. 4 is a graph comparing the structure and thermal radiation loading of a conventional substrate with a substrate of the present disclosure;

FIG. 5 is a graph comparing thermal radiation data for a conventional substrate and a substrate of the present disclosure;

FIG. 6 is a flow chart of a process for forming a silicon carbide ring provided by an embodiment of the present disclosure.

In the figure:

100 furnace body, 101 gas inlet, 102 gas outlet, 103 reaction chamber, 104 heating device,

201, a rotating table, 202 a rotating shaft,

300 substrate, 301 outer ring surface, 302 inner ring surface, 303 groove, 304 upper surface, 305 chamfer, 306 lower surface.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that are conventionally placed when the products of the present invention are used, and are used only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements to be referred to must have specific orientations, be constructed in specific orientations, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the research on the problem that silicon carbide prepared by chemical vapor deposition is easy to cause plasma path deviation, the inventor finds that the annular silicon carbide component grown by the method has the phenomenon that the edge position is thick and the inner part is thin in the radial direction, and the grain size and the structure of the thick and thin position have certain difference. The inventors have repeatedly conducted experimental analysis to obtain the reasons for the above phenomena: the edge position of the large-size graphite substrate is directly subjected to the heat radiation of the heater, and the temperature is higher than the inner position of the substrate, so that C/Si atoms are preferentially nucleated and deposited in the process; as the deposition process continues, the thickness difference between the edge side and the inner side of the substrate gradually increases, and the influence of the chemical vapor deposition reaction boundary layer is caused, further deteriorating the uniformity of the silicon carbide deposition material.

Fig. 1 shows a schematic structural view of a chemical vapor deposition apparatus to which the present disclosure relates, with which a process of forming a silicon carbide ring of the present disclosure is carried out. Referring to fig. 1, the chemical vapor deposition apparatus includes a furnace body 100, the furnace body 100 defining a reaction chamber 103, an inlet 101 disposed at an upper portion of the furnace body 100, an outlet 102 disposed at a lower portion of the furnace body 100, the inlet 101 and the outlet 102 both communicating with the reaction chamber 103, and the inlet 101 and the outlet 102 may be disposed in a diagonal manner in order to extend a flow path of gas in the reaction chamber 103. The gas inlet 101 delivers the mixed gas containing the precursor and other reaction gases to the reaction chamber 103, the precursor and other reaction gases are reacted and deposited in the furnace body 100, and the gas outlet 102 discharges the mixed substance containing unreacted precursor and gases, reaction products and other by-products from the furnace body 100, so that new precursor and other reaction gases can enter the reaction chamber 103.

The furnace body 100 is provided with a heating device 104, and the heating device 104 can be distributed around the inner wall of the furnace body 100 at intervals. In one possible implementation, the heating device 104 is a resistance heating device 104, and the environment inside the reaction chamber 103 is heated using heat radiation generated after passing an electric current through the resistance heating device 104.

The furnace body 100 bottom is equipped with the revolving stage 201, and it has a plurality of rotation axiss 202 to distribute along circumference on the revolving stage 201, can set up revolving stage driving piece and rotation axis driving piece outside the furnace body 100, and the revolving stage driving piece is used for driving revolving stage 201 and rotates for furnace body 100 bottom, and the rotation axis driving piece is used for driving rotation axis 202 and rotates for revolving stage 201. In order to improve the carbon/silicon atom deposition uniformity, the rotation direction of the rotation table 201 is set to be opposite to the rotation direction of the rotation shaft 202, and the rotation speed of the rotation table 201 is not higher than 3 rpm and is consistent with the rotation speed of the rotation shaft 202.

The rotation shaft 202 is provided with a plurality of substrates 300, and the plurality of substrates 300 are spaced apart from each other in the longitudinal direction of the rotation shaft 202. In a possible implementation manner, a clamping groove may be disposed on the annular body, a connecting rod is disposed on the rotating shaft 202, the connecting rod is clamped into the clamping groove to complete the combination of the substrate 300 and the rotating shaft 202, and the substrate 300 is fixed on the rotating shaft 202, so that the substrate 300 does not shake violently during the rotation of the rotating shaft 202.

As explained above, the conventional substrate has the phenomenon that the edge position in the radial direction of the silicon carbide ring is thick and the inner part is thin due to non-uniform temperature during the use process, and the grain size and the structure of the thick and thin position have certain difference. To solve this problem, the present disclosure provides an improved design of the substrate, specifically including a substrate undercut design. The inventor analyzes and finds that the main reasons for the large temperature difference in the substrate radial direction are: the outer part of the substrate is closer to the heating device in space, more heat radiation can be received, the temperature is higher than the inner part of the substrate, and the nucleation and the growth of the film material are easier. In order to reduce the temperature difference, the outer side ring surface of the substrate is hollowed, so that the surface receiving heat radiation is closer to the inner side of the substrate, and the temperature difference of the surface of the substrate is improved.

Further, because the edge of the substrate is closer to the heating device, there is a certain temperature difference between the inner side and the outer side of the substrate, and the chemical vapor deposition reaction boundary layer is generated, namely: the edge temperature of the substrate is high, the deposition speed of carbon/silicon atoms at the edge of the substrate is high, and the height of the silicon carbide layer at the edge of the substrate is increased along with the lengthening of the deposition time, so that the nucleation and the diffusion of the carbon/silicon atoms towards the inner side of the substrate can be prevented. However, in order to reduce the influence of the chemical vapor deposition reaction boundary layer caused by the excessive thickness of the outer edge of the substrate, the chamfer design is performed at the edge position of the substrate so as to reduce the influence caused by the excessive thickness of the thin film material at the edge position.

Fig. 2 and 3 show the structure of a substrate 300 based on the above design concept, and referring to fig. 2 and 3, the substrate 300 is selected from a ring-shaped structure made of high-purity graphite material in this embodiment, and may be high-purity silicon carbide in another embodiment. Typically, the silicon carbide ring is sized to have an outer diameter of 360 mm and an inner diameter of 240 mm, such that the ring substrate 300 has an inner diameter of 200 mm-280 mm and an outer diameter of 330 mm-400 mm. The size requirement of the required silicon carbide ring may also change for different types of plasma etching equipment, and the ring-shaped substrate 300 may be increased or decreased according to the actual requirement. The annular body is provided with a groove 303, and the groove 303 extends from the outer annular surface 301 of the annular body to the inner annular surface 302 of the annular body. The chamfer 305 transitions between the upper surface 304 of the annular body and the outer annular surface 301 and between the lower surface 306 of the annular body and the outer annular surface 301. Specifically, the chamfer 305 may be a planar chamfer 305 or a curved chamfer 305. The substrate 300 edge bevel 305 design can improve the non-uniformity of chemical vapor deposition caused by the outer edge thickness of the substrate 300. The groove 303 is formed on the outer ring surface 301 of the substrate 300, so that the surface of the substrate 300 receiving heat radiation is closer to the inner side in space, the temperature difference of the surface of the substrate 300 is effectively improved, and the carbon/silicon atoms on the surface of the substrate 300 are more uniformly deposited, such as the thickness and the structure of a thin film.

In a possible implementation manner, the groove bottom and the groove wall of the groove 303 on the ring-shaped body are both arc surfaces, the cross section of the groove 303 is in the shape of a conical parabolic curve, and the distance between two opposite side walls of the groove gradually decreases from the groove opening of the groove to the groove bottom of the groove, as shown in fig. 3. The section of the groove is set to be a conical parabolic curve, so that no edge angle exists in the groove, and further no airflow dead angle exists, and airflow flowing is facilitated; in addition, the distance between the two side walls of the groove is gradually reduced from the notch of the groove to the groove bottom, so that the support strength of the annular body can be ensured. In addition, the cross-sectional shape of the groove 303 may be rectangular, trapezoidal, "C" shape, "<" shape, ". Angle" shape, or the like.

The structure shown in FIG. 1 comprises 3 rotating shafts 202, each rotating shaft 202 is provided with 11 substrates 300, and the deposition process of the 3-shaft 11-layer silicon carbide edge ring is adopted, wherein the processing size of the inner diameter and the outer diameter of the high-purity graphite substrate 300 is 200mm to 400mm. Because the substrate 300 is large in size, the temperature of the surface of the substrate 300 needs to be maintained in order to ensure uniform deposition of the silicon carbide material on the surface of the substrate 300. To ensure the uniformity of the silicon carbide material deposition along the circumferential direction of the substrate 300, the rotating table 201 drives the rotating shaft 202 to perform a slow clockwise rotation at a speed of 1 rpm, and the rotating shaft 202 also performs a slow counterclockwise rotation at a speed of 1 rpm. Meanwhile, in order to ensure the uniformity of the silicon carbide material deposited in the radial direction of the substrate 300 and reduce the influence of the temperature difference between the inner side and the outer side of the substrate 300 in the radial direction and the thickness difference of the inner side and the outer side deposited film layers, the substrate 300 is improved as described above: 1. designing an internal hollow part; 2. the substrate 300 edge is chamfered 305 design. The chemical vapor deposition equipment shown in FIG. 1 is used in the following process: the heating temperature of the heating device 104 is 1050 ℃, the carrier gas hydrogen carries the precursor methyltrichlorosilane to enter the reaction chamber 103 in the furnace body 100 through the air inlet 101, the precursor is decomposed at high temperature, carbon/silicon atoms are subjected to a complex decomposition adsorption reaction process, and finally, silicon carbide material is deposited on the surface of the substrate 300, and the unreacted gas and the mixture of other byproducts are discharged from the exhaust port 102.

In order to confirm the improvement effect, simulation calculation was performed on the conventional and improved substrates by simulation software to confirm the temperature difference between the surfaces of the substrates, the comparison between the conventional substrate and the substrate of the present disclosure is shown in fig. 4, the left side 3-1 of fig. 4 is a schematic thermal radiation diagram of the conventional substrate, and the right side 3-2 of fig. 4 is a schematic thermal radiation diagram of the substrate of the present disclosure. The conventional substrate and the substrate of the present disclosure in fig. 4 have the same data of the inner diameter and the outer diameter, wherein the inner diameter is 300mm and the outer diameter is 400mm. The resistance heating device is designed to be 1050 ℃, the substrate is heated in a radiation mode, only radiation to the outer side face of the substrate is considered for purposefully amplifying and improving the effect (as shown in figure 5), thermal convection between the surface of the substrate and the environment is considered, and the fact that the difference of two sets of simulation experiment conditions is only the edge chamfering design and the external hollowing design of the substrate is guaranteed. As shown in FIG. 5, the left side 4-1 in FIG. 5 is the experimental data of the conventional substrate, and the right side 4-2 in FIG. 5 is the experimental data of the substrate of the present disclosure, and it can be seen from FIG. 5 that the temperature difference between the inner side and the outer side of the conventional substrate is 31.99 deg.C, the temperature difference between the inner side and the outer side of the substrate of the present disclosure is 16.06 deg.C, and the trend of the temperature versus radial variation curve of the two is also changed. In addition, the result shows that the highest temperature of the substrate is higher than that of the traditional substrate, the analysis reason is that the situation considered by the simulation experiment is ideal, the surface of the outer side surface of the improved substrate device, which receives radiation, is a curved surface, the area is larger, and therefore the received heat energy is higher. Although the actual process is very complicated due to the thermal environment in the growth furnace, and the temperature difference between the inner side and the outer side of the substrate is not dozens of degrees, the simulation result shows that the scheme is beneficial to improving the temperature difference of the substrate in the radial direction from the qualitative angle, thereby improving the uniformity of silicon carbide material deposition.

The embodiment of the disclosure also provides a forming process of a silicon carbide ring, which can be implemented by adopting the chemical vapor deposition equipment. Referring to fig. 6, the process for forming the silicon carbide ring includes the following steps S1 to S6.

S1: installing a substrate in a reaction chamber of chemical vapor deposition equipment; the furnace body of the chemical vapor deposition equipment limits the reaction chamber, a heating device is arranged on the furnace body, the heating device surrounds the substrate, the substrate is an annular body with a groove, the groove extends from the outer ring surface of the annular body to the inner ring surface of the annular body, and the upper surface of the annular body and the outer ring surface and/or the lower surface of the annular body and the outer ring surface are in chamfer transition.

Wherein the substrate is made of a high-purity graphite material. The ring substrate has an inner diameter of 200 mm-280 mm and an outer diameter of 330 mm-400 mm.

S2: and vacuumizing the reaction chamber.

Specifically, the reaction chamber was evacuated to 0.1 to 0.01 Torr.

S3: and operating the heating device to heat the reaction chamber to a preset temperature.

The preset temperature is 1050-1600 ℃.

S4: introducing reaction gas into the reaction chamber, wherein the reaction gas comprises carrier gas, diluent gas and a precursor containing carbon element and silicon element; and decomposing and depositing the reaction gas on the surface of the substrate at the preset temperature to form a silicon carbide layer.

And discharging reaction byproducts out of the reaction chamber while introducing reaction gas into the reaction chamber. Specifically, in the step S4, introducing methyltrichlorosilane serving as a precursor into the reaction chamber, wherein the flow rate is 6 SLPM-12 SLPM; introducing hydrogen as a carrier gas into the reaction chamber, wherein the flow rate is 40 SLPM-100 SLPM; and introducing nitrogen serving as diluent gas into the reaction chamber, wherein the flow rate is 3-40 LPM. The methyl trichlorosilane can be decomposed into radicals of carbon and silicon atoms at high temperature, the radicals are diffused and adsorbed on the graphite substrate to deposit the silicon carbide material, and the rest byproducts are discharged through an exhaust port.

S5: and when the silicon carbide layer deposited on the substrate meets the preset conditions, closing the heating device, and taking out the substrate deposited with the silicon carbide layer after cooling.

Observing the growth condition of the silicon carbide material on the surface of the substrate, and closing the heating device for cooling after the silicon carbide layer grows to a certain thickness; and when the temperature is reduced to be below 80 ℃, opening the cavity and taking out the graphite substrate with the silicon carbide material deposited on the surface.

S6: and stripping the substrate to obtain the silicon carbide ring.

The method comprises the steps of removing graphite substrate materials through machining to obtain silicon carbide rings, obtaining two silicon carbide rings on one graphite substrate due to the fact that silicon carbide is deposited on the upper surface and the lower surface of the graphite substrate, cutting the silicon carbide rings to the required inner diameter and outer diameter by utilizing a linear cutting process, grinding and polishing the surfaces of the silicon carbide rings to achieve the required surface roughness, and then removing impurity oil stains on the surfaces of the silicon carbide rings through a cleaning process to obtain the usable silicon carbide ring component. The silicon carbide ring component can be applied to plasma etching core components.

The disclosure also provides a silicon carbide ring for plasma etching equipment, which is prepared by adopting the forming process of the silicon carbide ring.

The present disclosure improves the thickness and texture property uniformity of a substrate surface deposited silicon carbide film in the radial direction. Specifically, by arranging the groove on the outer annular surface of the annular substrate, when the heating device surrounding the substrate heats, the groove structure can improve the temperature difference caused by the difference between the inner side and the outer side of the substrate and the spatial position of the heating device, improve the temperature uniformity of the surface of the substrate in the radial direction, and ensure that the carbon/silicon atom deposition on the surface of the substrate is more uniform. By designing the chamfer transition of the upper surface, the lower surface and the outer annular surface of the substrate, the influence of nucleation and diffusion of a chemical vapor deposition reaction boundary layer and carbon/silicon atoms to the inner side of the substrate, which are caused by the over-thick outer edge of the substrate, is reduced, the deposition uniformity of the silicon carbide material can be further improved, and the radial thickness difference of the silicon carbide layer is reduced. The method has obvious benefit for improving the temperature difference of the substrate grown by the resistance heating furnace and the large-size and thick-film material.

It is to be noted that the foregoing description is only exemplary of the invention and that the principles of the technology may be employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments illustrated herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A molding process of a silicon carbide ring is characterized by comprising the following steps:

s1: installing a substrate in a reaction chamber of chemical vapor deposition equipment; the furnace body of the chemical vapor deposition equipment limits the reaction chamber, a rotating table and at least one rotating shaft are arranged in the reaction chamber, the rotating table is rotatably arranged on the bottom wall of the furnace body, the at least one rotating shaft is arranged close to the edge of the rotating table, and the substrate is arranged on the rotating shaft; the furnace body is provided with a heating device, the heating device surrounds the substrate, the substrate is an annular body with a groove, and the groove extends from the outer annular surface of the annular body to the inner annular surface of the annular body;

s2: vacuumizing the reaction chamber;

s4: introducing reaction gas into the reaction chamber, wherein the reaction gas comprises carrier gas, diluent gas and a precursor containing carbon element and silicon element; the reaction gas is decomposed and deposited on the surface of the substrate at the preset temperature to form a silicon carbide layer; when the reaction gas is introduced into the reaction chamber, the rotating table rotates relative to the furnace body, and the rotating shaft rotates relative to the rotating table;

s6: and stripping the substrate to obtain the silicon carbide ring.

2. The process for molding a silicon carbide ring according to claim 1, wherein a transition between an upper surface of the annular body and the outer annular surface and/or a transition between a lower surface of the annular body and the outer annular surface is chamfered.

3. The process for forming a silicon carbide ring according to claim 1 or 2, wherein the cross-sectional shape of the groove is a conic parabolic curve.

4. The process for forming the silicon carbide ring according to claim 1, wherein the substrate is made of graphite material with ash content less than 50ppm or silicon carbide material with purity greater than 99.999%.

5. The process for forming a silicon carbide ring according to claim 1, wherein the reaction chamber is evacuated to 0.1 to 0.01 Torr in the step S2.

6. The process for forming a silicon carbide ring according to claim 1, wherein the predetermined temperature in step S3 is 1050 ℃ to 1600 ℃.

7. The process for molding a silicon carbide ring according to claim 1, wherein the step S4 comprises: introducing methyltrichlorosilane serving as a precursor into the reaction chamber, wherein the flow rate is 6 SLPM-12 SLPM; introducing hydrogen as a carrier gas into the reaction chamber, wherein the flow rate is 40 SLPM-100 SLPM; and introducing nitrogen serving as diluent gas into the reaction chamber, wherein the flow rate is 3-40 LPM.

8. The process of claim 1, further comprising, after step S6: machining the silicon carbide ring to a target size.

9. The process for forming a silicon carbide ring according to claim 1,

the chemical vapor deposition equipment further comprises a rotating table driving part and a rotating shaft driving part, when the reaction chamber is filled with reaction gas, the rotating table driving part drives the rotating table to rotate relative to the furnace body, the rotating shaft driving part drives the rotating shaft to rotate relative to the rotating table, and the rotating direction of the rotating table is opposite to the rotating direction of the rotating shaft.