Patent Description:
In the semiconductor apparatus technical field, Metal-Organic Chemical Vapor Deposition (MOCVD) is a new vapor phase epitaxial growth technology developed based on vapor phase epitaxial growth. In MOCVD, organic compounds of a group III element and a group II element and hydrides of a group V element and a group VI element are used as crystal growth source materials, vapor phase epitaxy is performed on a substrate in a thermal decomposition reaction manner to grow various compound semiconductors of group III-V and group II-VI and thin layer single crystal materials of a multi-element solid solution of the compound semiconductors of group III-V and group II-VI.

Generally, the chamber includes two plate electrodes that are spaced at a certain interval and parallel to each other, wherein one plate electrode is connected to radio frequency and the other plate electrode is grounded. After a required material is grown on the surface of the substrate, a process gas is uniformed through a uniform flow chamber, then enters between the two plate electrodes, and is excited under an action of a radio frequency electric field to generate a plasma. The plasma reacts with the material generated by MOCVD on the surface of the substrate to reduce resistivity of a surface film layer of the substrate. For example, a spray plate <NUM> and a base <NUM> in <CIT>, and an upper electrode <NUM> and a lower electrode <NUM> in <CIT>, all adopt the structures similar to the above plate electrode.

In a specific application process, since resistivity required by different materials are different, different RF power needs to be adjusted to perform the reaction. However, after the radio frequency power is increased, a sparking phenomenon occurs due to an accidental discharge, which occurs between a radio frequency electrode and a metal gas inlet of the chamber. Thus, uniformity of the resistivity of the surface material of the substrate is affected. For example, <CIT> discloses a common gas inlet structure.

The present disclosure discloses a reaction chamber to solve the problem that accidental sparking is easy to occur in an existing reaction chamber.

In order to solve the above problems, the present disclosure adopts the following technical solutions.

In some embodiments, the insulation body includes at least two insulation blocks arranged in sequence in the axial direction of the through-hole, and each insulation block is provided with a gas inlet hole used as a channel segment.

In some embodiments, two insulation blocks are provided and include a first insulation block close to the inner chamber and a second insulation block facing away from the inner chamber, wherein the first insulation block is provided with a first gas inlet hole used as the channel segment, an accommodation space is formed on one side of the first insulation block facing away from the inner chamber, the second insulation block is arranged in the accommodation space, and the second insulation block is provided with a second gas inlet hole used as the channel segment.

In some embodiments, a gas inlet groove is arranged on an outer peripheral surface of the second insulation block, and the gas inlet groove and an inner wall of the accommodation space form the second gas inlet hole.

In some embodiments, a first groove is formed on a side of the second insulation block facing the inner chamber, the first groove and the inner wall of the accommodation space form a first gas chamber, and both the first gas inlet hole and the second gas inlet hole are communicated with the first gas chamber.

In some embodiments, a plurality of second gas inlet holes are provided and distributed along a peripheral direction of the first groove at intervals, and an orthographic projection of an inner peripheral surface of the first groove on a plane perpendicular to an axial direction of the through-hole overlaps partially with orthographic projections of the second gas inlet holes on the plane perpendicular to the axial direction of the through-hole.

In some embodiments, a plurality of first gas inlet holes are provided and arranged at the first insulation block at intervals.

In some embodiments, a second groove is provided on a side of the second insulation block facing away from the inner chamber (<NUM>), the second groove and the flange part form a second gas chamber, and the second gas chamber is respectively communicated with the gas inlet end of the gas inlet channel and the gas outlet end of the gas inlet pipe.

In some embodiments, a third groove is formed on a side of the flange part facing the second insulation block, and the third groove is butted with the second groove to form the second gas chamber.

In some embodiments, the gas inlet mechanism further includes a position limiting structure, and the position limiting structure is arranged between an outer peripheral surface of the second insulation block and an inner wall of the accommodation space to limit rotation of the second insulation block in the accommodation space.

In some embodiments, the reaction chamber is a metal-organic compound chemical vapor deposition process chamber.

The technical solution adopted by the present disclosure can achieve the following beneficial effects.

In the reaction chamber disclosed by embodiments of the present disclosure, orthographic projections of any two adjacent channel segments of the gas inlet channel on the plane perpendicular to the axial direction of the through-hole are staggered from each other. In this case, when the upper cover is powered-on through the electrode, a radio frequency electric field is difficult to be formed between the grounded flange part and the upper cover and the powered-on part of the upper cover. Thus, the occurrence of accidental discharge phenomenon may be reduced, the risk of generating the sparking phenomenon may be reduced, and finally, the uniformity and stability of the surface material of the substrate may be improved.

The accompanying drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. Exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure and do not form an improper limitation to the present disclosure. In the accompanying drawings:.

In order to make the purposes, technical solutions, and advantages of the present disclosure clearer, the technical solutions of the present disclosure will be clearly and completely described below in connection with specific embodiments of the present disclosure and the corresponding accompanying drawings. Apparently, the described embodiments are only some embodiments of the present disclosure, not all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on embodiments of the present disclosure without creative efforts shall be within the scope of the present disclosure.

The technical solutions disclosed in various embodiments of the present disclosure are described in detail below in connection with the accompanying drawings.

As shown in <FIG>, the first embodiment of the present disclosure discloses a reaction chamber. The disclosed reaction chamber may be a metal-organic chemical vapor deposition (MOCVD) process chamber. The disclosed reaction chamber includes a chamber body <NUM>, an upper cover <NUM>, and a gas inlet mechanism.

Referring to <FIG>, the chamber body <NUM> is grounded. The upper cover <NUM> is electrically connected to an electrode <NUM>. One end of the electrode <NUM> may be arranged, e.g., on the upper cover <NUM>, and the other end is electrically connected to a radio frequency source and configured to load radio frequency power output by the radio frequency source to the upper cover <NUM>. The chamber body <NUM> and the upper cover <NUM> are connected by an insulation member <NUM>. In the case that the chamber body <NUM> is connected to the upper cover <NUM>, the chamber body <NUM> and the upper cover <NUM> form an inner chamber <NUM>. A portion of the inner chamber <NUM> that corresponds to the chamber body <NUM> may be a first hollow chamber, and a portion that corresponds to the upper cover <NUM> may be a second hollow chamber, wherein a heater <NUM> is arranged in the first hollow chamber and configured to carry a substrate and heat the substrate. In a process of performing chemical vapor deposition, organic compounds of a group III element and a group II element and hydrides of a group V element and a group VI element may be used as crystal growth source materials, and vapor phase epitaxy may be performed at the heater <NUM> in a thermal decomposition reaction manner to grow various compound semiconductors of group III-V and group II-VI and thin layer single crystal material of a multi-element solid solution thereof. At the same time, in order to reduce resistivity of the material, the heater <NUM> is grounded through the chamber body <NUM>.

Referring again to <FIG>, a uniform flow plate <NUM> and a showerhead <NUM> are arranged in the second hollow chamber. The uniform flow plate <NUM> is arranged opposite to the showerhead <NUM>, and the showerhead <NUM> is arranged opposite to the heater <NUM>. When the process is performed, the reaction gas first flows into the second hollow chamber. The uniform flow plate <NUM> in the second hollow chamber body may be configured to uniform the reaction gas to cause the reaction gas flowing out of the uniform flow plate <NUM> to be relatively uniform. Thereafter, the reaction gas flowing out of the uniform flow plate <NUM> flows into the showerhead <NUM>. The showerhead <NUM> may be configured to spray the reaction gas flowing through to a surface of the substrate on the heater <NUM> to perform a vapor phase epitaxy reaction, so as to grow the required material on the surface of the substrate. In addition, the showerhead <NUM> may be electrically connected to the upper cover <NUM>. When the upper cover <NUM> is powered-on, the showerhead <NUM> may be powered-on. A radio frequency electric field may be formed between the powered-on showerhead <NUM> and the grounded heater <NUM>. The radio frequency electric field may reduce the resistivity of the material grown on the surface of the substrate.

Correspondingly, a through-hole <NUM> is arranged at the upper cover <NUM> in communication with the inner chamber <NUM>. The gas inlet mechanism includes an insulation body <NUM>, which is at least partially arranged in the through-hole <NUM>. A gas inlet channel may be arranged in the insulation body <NUM>, and a gas outlet end of the gas inlet channel may be communicated with the inner chamber <NUM>. A flange part <NUM> is arranged on a side of the insulation body <NUM> facing away from the inner chamber <NUM>. The flange part <NUM> may be grounded and configured to communicate the gas inlet end of the gas inlet channel with a gas outlet end of a gas inlet pipe <NUM> configured to transfer the reaction gas. The flange part <NUM> is sealed and connected to the gas inlet pipe <NUM>, so that the gas outlet end of the gas inlet pipe <NUM> may be communicated with the gas inlet end of the gas inlet channel. The other end of the gas inlet pipe <NUM> may be communicated with a container having the reaction gas.

The insulation body <NUM> may have a plurality of structures. In embodiments of the present disclosure, the insulation body <NUM> includes two insulation blocks arranged along an axis of the through-hole <NUM> in sequence, that is a first insulation block <NUM> close to the inner chamber <NUM> and a second insulation block <NUM> facing away from the inner chamber <NUM>. At least a part of the first insulation block <NUM> may be located in the through-hole <NUM>. As shown in <FIG>, one side of the first insulation block <NUM> facing away from the inner chamber <NUM> is provided with an accommodation space <NUM>, and the second insulation block <NUM> is arranged in the accommodation space <NUM>. As shown in <FIG>, the flange part <NUM> is arranged on a side surface of the first insulation block <NUM> facing away from the inner chamber <NUM> and blocks an opening of the accommodation space <NUM>.

The second insulation block <NUM> is provided with a second gas inlet hole <NUM>. The first insulation block <NUM> is provided with a first gas inlet hole <NUM>. A gas inlet end of the first gas inlet hole <NUM> is communicated with a gas outlet end of the second gas inlet hole <NUM>. The gas outlet end of the first gas inlet hole <NUM> is communicated with the inner chamber <NUM>. Under this situation, the first gas inlet hole <NUM> and the second gas inlet hole <NUM> constitute two channel segments of the gas inlet channel, respectively. The reaction gas in the gas inlet pipe <NUM> may sequentially pass through the second gas inlet hole <NUM> and the first gas inlet hole <NUM> to flow into the inner chamber <NUM>. In embodiments of the present disclosure, orthographic projections of the first gas inlet hole <NUM> and the second gas inlet hole <NUM> are staggered from each other on a plane perpendicular to an axial direction of the through-hole <NUM>. That is, an axis of the first gas inlet hole <NUM> is not in a straight line with an axis of the second gas inlet hole <NUM>. The orthographic projection of the first gas inlet hole <NUM> is outside the orthographic projection of the second gas inlet hole <NUM>. As such, when the upper cover is powered-on through the electrode, a radio frequency electric field is difficult to be formed between the grounded flange part and the upper cover and a powered-on part of the upper cover. Thus, occurrences of accidental discharge phenomenon may be reduced, a risk of generating the sparking phenomenon may be further reduced, and finally, the uniformity and stability of the surface material of the substrate may be improved.

In embodiments of the present disclosure, as shown in <FIG>, a gas inlet groove is arranged at an outer peripheral surface of the second insulation block <NUM>. The gas inlet groove ad an inner wall of the accommodation space <NUM> form the second gas inlet hole <NUM>. Compared with directly arranging the second gas inlet hole <NUM> in the second insulation block <NUM>, an arrangement of the gas inlet groove may be easier to process and form. Meanwhile, in this manner, the second gas inlet hole <NUM> may be caused to be in an edge region of the second insulation block <NUM>. Thus, the orthographic projection of the second gas inlet hole <NUM> on the plane perpendicular to the axial direction of the through-hole <NUM> may be easier to be located outside the orthographic projection of the first gas inlet hole <NUM> on the plane perpendicular to the axial direction of the through-hole <NUM>. Thus, a staggered effect of the second gas inlet hole <NUM> and the first gas inlet hole <NUM> may be better, which is the main advantage of the present disclosure.

As shown in <FIG>, a first groove 522a is arranged on a side of the second insulation block <NUM> facing the inner chamber <NUM>. The first groove 522a and the inner wall of the accommodation space <NUM> form a first gas chamber. The first gas inlet hole <NUM> is communicated with the second gas inlet hole <NUM> through the first gas chamber. When the process is performed, the reaction gas may first enter the first gas chamber via the second gas inlet hole <NUM>. The reaction gas that enters the first gas chamber may flow into the inner chamber <NUM> via the first gas inlet hole <NUM>. In such a manner, the first gas inlet hole <NUM> may be facilitated to be communicated with the second gas inlet hole <NUM>, and other parts on a side of the second insulation block <NUM> facing the inner chamber <NUM> may be better supported in the accommodation space <NUM>, which facilitates the overall assembly. Of course, in practical applications, the communication between the first gas inlet hole <NUM> and the second gas inlet hole <NUM> may be realized by using any other structure.

In embodiments of the present disclosure, in an optional solution, as shown in <FIG>, a plurality of second gas inlet holes <NUM> are included and are distributed along a circumferential direction of the first groove 522a at intervals. The plurality of second gas inlet holes <NUM> may be configured to increase a circulation rate of the reaction gas. Meanwhile, diameters of the plurality of second gas inlet holes <NUM> may be relatively small. Thus, the radio frequency electric field may be difficult to be generated between the flange part <NUM> and the upper cover <NUM> and a powered-on part of the upper cover <NUM>, thereby better preventing generation of accidental discharge.

Moreover, the orthographic projection of an inner peripheral surface of the first groove 522a on the plane perpendicular to the axial direction of the through-hole <NUM> may overlap with orthographic projections of the plurality of second gas inlet holes <NUM> on the plane perpendicular to the axial direction of the through-hole <NUM>. For example, a plurality of gas inlet grooves may be arranged on the outer peripheral surface of the second insulation block <NUM> and distributed along a peripheral direction of the second insulation block <NUM> at intervals. The gas inlet grooves may form a plurality of second gas inlet holes <NUM> with the inner wall of the accommodation space <NUM>. Moreover, as shown in <FIG>, diameter D1 of the first groove 522a is larger than diameter D2 of an inscribed circle formed by inner side edges of the plurality of gas inlet grooves. Thus, the first groove 522a may be communicated with the gas inlet grooves.

In embodiments of the present disclosure, as shown in <FIG>, a side of the second insulation block <NUM> facing away from the inner chamber <NUM> may be provided with a second groove 522b. The second groove 522b may form a second gas chamber with the flange part <NUM>. The gas outlet end of the gas inlet pipe <NUM> may be communicated with the gas inlet end of the second gas inlet hole <NUM> through the second gas chamber. When the process is performed, the reaction gas in the gas inlet pipe <NUM> may first enter the second gas chamber, and then enters the second gas inlet hole <NUM> through the second gas chamber. In such a manner, the gas inlet pipe <NUM> may be facilitated to be communicated with the second gas inlet hole <NUM>. Under this situation, the gas inlet pipe <NUM> may not need to be directly connected to the second gas inlet hole <NUM>. Thus, assembly difficulty may be reduced. At the same time, when a plurality of second gas inlet holes <NUM> are included, the second gas chamber may enable the reaction gas flowing out from the gas inlet pipe <NUM> to flow into the second gas inlet holes <NUM>. Thus, while the circulation rate of the reaction gas is increased, generation of an accidental discharge phenomenon may be prevented.

Optionally, as shown in <FIG>, a third groove <NUM> is arranged on a side of the flange part <NUM> facing the second insulation block <NUM>. The third groove <NUM> may be butted with the second groove 522b to form the second gas chamber to realize the communication between the gas inlet pipe <NUM> and the second gas inlet hole <NUM>. Of course, in practical applications, only the second groove 522b may be provided, or only the third groove <NUM> may be provided.

Similarly, a plurality of first gas inlet holes <NUM> may be provided and arranged at the first insulation block <NUM> at intervals. The plurality of first gas inlet holes <NUM> may enable the gas flowing out of the second gas inlet hole <NUM> to flow quickly into the inner chamber <NUM>. Similarly, diameters of the plurality of first gas inlet holes <NUM> may be relatively small. Thus, the radio frequency electric field may be difficult to be formed between the flange part <NUM> and the upper cover <NUM> and the powered-on part of the upper cover <NUM>, and generation of accidental discharge may be better prevented. Optionally, under such a situation, the plurality of second gas inlet holes <NUM> may be provided at the second insulation block <NUM> at intervals. The plurality of second gas inlet holes <NUM> may be communicated with the plurality of first gas inlet holes <NUM> to increase the circulation rate of the reaction gas.

In embodiments of the present disclosure, the gas inlet mechanism may further include a position limiting structure. The position limiting structure may be arranged between the outer peripheral surface of the second insulation block <NUM> and the inner wall of the accommodation space <NUM> to limit rotation of the second insulation block <NUM> in the accommodation space <NUM>. For example, as shown in <FIG>, the position limiting structure includes a convex member <NUM> arranged on the outer peripheral surface of the second insulation block <NUM> and a concave member arranged on the inner wall of the accommodation space <NUM>. The convex member <NUM> may cooperate with the concave member to prevent the second insulation block <NUM> from rotating in the accommodation space <NUM>. Optionally, the convex member <NUM> may be an integral structure with the second insulation block <NUM>. In this case, the inner wall of the accommodation space <NUM> may be provided with a mounting groove, and at least a part of the convex member <NUM> may be located in the mounting groove.

In embodiments of the present disclosure, the first insulation block <NUM> may include a body member <NUM> and a position limiting member <NUM>. The body member <NUM> may be connected to the position limiting member <NUM>. The body member <NUM> may be arranged in the through-hole <NUM>. The position limiting member <NUM> may be position-limited and cooperate with a side of the through-hole <NUM> facing away from the inner chamber <NUM>. With such a manner, the connection between the first insulation block <NUM> and the through-hole <NUM> may be facilitated. At the same time, the position limiting member <NUM> may not only have a position-limiting and cooperation function with the side of the through-hole <NUM> facing away from the inner chamber <NUM>, but the position limiting member <NUM> may also have a relatively large outer surface. Thus, the accommodation space <NUM> may be facilitated to be arranged.

A difference of a reaction chamber provided by the second embodiment of the present disclosure, when the reaction chamber is compared to the reaction chamber of the first embodiment only includes that the structure of the insulation body is different. Specifically, referring to <FIG>, in embodiments of the present disclosure, a gas inlet channel is arranged in the insulation body <NUM>'. The insulation body <NUM>' includes three insulation blocks sequentially arranged in a vertical direction (i.e., the same direction as the axial direction of the through-hole <NUM> in <FIG>), which are a first insulation block 503a, a second insulation block 503b, and a third insulation block 503c arranged sequentially along a direction close to the inner chamber <NUM>. The three insulation blocks may be sequentially stacked in the axial direction of the through-hole <NUM>. A third gas inlet hole 501c may be arranged in the third insulation block 503c, a second gas inlet hole 501b may be arranged in the second insulation block 503b, and a first gas inlet hole 501a may be arranged in the first insulation block 503a. The first gas inlet hole 501a, the second gas inlet hole 501b, and the third gas inlet hole 501c may constitute three channel segments of the gas inlet channel, respectively.

A gas outlet end of the third gas inlet hole 501c may be communicated with the inner chamber <NUM>, and a gas inlet end of the third gas inlet hole 501c may be communicated with a gas outlet end of the second gas inlet hole 501b, for example, through a second connection channel 502b arranged in the insulation body <NUM>'. A gas inlet end of the second gas inlet hole 501b may be communicated with a gas outlet end of the first gas inlet hole 501a, for example, through a first connection channel 502a arranged in the insulation body <NUM>'. A gas inlet end of the first gas inlet hole 501a may be communicated with a gas outlet end of the gas inlet pipe configured to transfer the reaction gas through the flange part. The flange part and the gas inlet pipe may adopt the same structure as the flange part <NUM> and the gas inlet pipe <NUM> shown in <FIG>. In this way, the reaction gas in the gas inlet pipe <NUM> may sequentially pass through the first gas inlet hole 501a, the second gas inlet hole 501b, and the third gas inlet hole 501c to flow into the inner chamber <NUM>.

In embodiments of the present disclosure, as shown in <FIG>, orthographic projections of the first gas inlet hole 501a, the second gas inlet hole 501b, and the third gas inlet hole 501c are staggered from each other on a plane perpendicular to the vertical direction. That is, any two axes of an axis of the first gas inlet hole 501a, an axis of the second gas inlet hole 501b, and an axis of the third gas inlet hole 501c are not in a straight line. For example, an orthographic projection of the second gas inlet hole 501b is outside an orthographic projection of the third gas inlet hole 501c. An orthographic projection of the first gas inlet hole 501a is located outside the orthographic projection of the second gas inlet hole 501b. In this way, when the upper cover is powered-on through the electrode, a radio frequency electric field may be difficult to be formed between the grounded flange part and the upper cover and the powered-on part of the upper cover. Thus, occurrence of accidental discharge phenomenon may be reduced, a risk of generating the sparking phenomenon may be reduced, and finally, the uniformity and stability of the surface material of the substrate may be improved.

In embodiments of the present disclosure, as shown in <FIG>, grooves are arranged on two opposite surfaces of the second insulation block 503b and the third insulation block 503c, respectively. The two grooves may be butted to form the first connection channel 502a. Similarly, grooves are arranged on two opposite surfaces of the second insulation block 503b and the first insulation block 503a, respectively. The two grooves may be butted to form the second connection channel 502b. Of course, in practical applications, a groove may also be provided on one of the two opposite surfaces of the second insulation block 503b and the third insulation block 503c, and the first connection channel 502a may also be formed. Moreover, a groove may be provided on one of the two opposite surfaces of the second insulation block 503b and the first insulation block 503a, and the second connection channel 502b may be also formed. In addition, in practical applications, the communication between the first gas inlet hole 501a and the second gas inlet hole 501b and the communication between the second gas inlet hole 501b and the third gas inlet hole 501c may be realized in any other manners, which is not particularly limited in embodiments of the present disclosure.

In embodiments of the present disclosure, as shown in <FIG>, optionally, a plurality of the first gas inlet holes 501a are provided and arranged along a peripheral direction of the insulation body <NUM>' at intervals. Similarly, a plurality of second gas inlet holes 501b are provided and arranged along the peripheral direction of the insulation body <NUM>' at intervals. The plurality of second gas inlet holes 501b are located on an inner side of the plurality of first gas inlet holes 501a. A plurality of third gas inlet holes 501c are provided and arranged on an inner side of the plurality of second gas inlet holes 501b. Thus, the circulation rate of the reaction gas may be increased.

It should be noted that, in embodiments of the present disclosure, the insulation body <NUM>' includes the three insulation blocks stacked in sequence in the vertical direction (i.e., the same direction as the axial direction of the through-hole <NUM> in <FIG>). Thus, the gas inlet holes and corresponding grooves may be machined conveniently for the three insulation blocks, and eventually, the continuous gas inlet channel may be formed. Moreover, orthographic projections of any two adjacent channel segments of the gas inlet channel may be staggered from each other in the vertical direction. However, embodiments of the present disclosure are not limited to this. In practical applications, the insulation body may be divided into a plurality of partitions in any manner, as long as the gas inlet channel having the structure described above may be machined and obtained. Alternatively, the insulation body may also adopt an integrated structure. The gas inlet channel having the structure described above may be formed in the integrated insulation body by using an existing processing manner. For example, holes may be formed in different directions of the insulation body. The channel segments staggered with each other may be further machined through the opening holes, and the connection channel communicating the adjacent channel segments may be machined. Then, the opening holes may be blocked to obtain a closed gas inlet channel.

Other structures and functions not mentioned in the reaction chamber provided by the second embodiment of the present disclosure are not repeated here, since the other structures and functions are the same as the structures and functions in the first embodiment.

It should be noted that, in practical applications, a number of insulation blocks included in the insulation body may also be four or more according to specific requirements. In addition, an arrangement manner between any two adjacent insulation blocks is not limited to the nesting manner in the above embodiments (that is, the upper insulation block is arranged in the accommodation space of the lower insulation block) and the stacking manner. In practical applications, the insulation blocks may be arranged in any other manners, for example, in a concentrically surrounding manner.

In embodiments of the present disclosure, the differences between the embodiments are emphasized to be described. Different optimization features between the embodiments may be combined to form a better embodiment as long as there is no contradiction, which is not repeated here to keep the brevity of the text.

Claim 1:
A reaction chamber for Metal-Organic Chemical Vapor Deposition, MOCVD, comprising:
a chamber body (<NUM>), the chamber body (<NUM>) being grounded;
an upper cover (<NUM>), the upper cover (<NUM>) being provided with an electrode (<NUM>), the chamber body (<NUM>) being connected to the upper cover (<NUM>) through an insulation member (<NUM>), the chamber body (<NUM>) and the upper cover (<NUM>) forming an inner chamber (<NUM>), and a through-hole (<NUM>) communicating with the inner chamber (<NUM>) being arranged at the upper cover (<NUM>);
a gas inlet mechanism, the gas inlet mechanism including a first insulation block (<NUM>), a second insulation block (<NUM>), a gas inlet pipe (<NUM>) and a flange part (<NUM>), one end of the gas inlet pipe (<NUM>) being connected to the flange part (<NUM>), at least a part of the first insulation block (<NUM>) being located in the through-hole (<NUM>), the second insulation block (<NUM>) being provided with a second gas inlet hole (<NUM>), the gas inlet pipe (<NUM>) being communicated with the second gas inlet hole (<NUM>), the first insulation block (<NUM>) being provided with a first gas inlet hole (<NUM>), one end of the first gas inlet hole (<NUM>) being communicated with the second gas inlet hole (<NUM>) and another end of the first gas inlet hole (<NUM>) being communicated with the inner chamber (<NUM>), a projection of the first gas inlet hole (<NUM>) being located outside a projection of the second gas inlet hole (<NUM>) in an axis direction of the through-hole (<NUM>);
characterized in that
a side of the first insulation block (<NUM>) facing away from the inner chamber (<NUM>) being provided with an accommodation space (<NUM>), the second insulation block (<NUM>) being arranged in the accommodation space (<NUM>), the flange part (<NUM>) being arranged at an opening of the accommodation space (<NUM>) and being located above the second insulation block (<NUM>),
an outer surface of the second insulation block (<NUM>) being provided with a gas inlet groove, the gas inlet groove and an inner wall of the accommodation space (<NUM>) forming the second gas inlet hole (<NUM>);
a side of the second insulation block (<NUM>) facing the inner chamber (<NUM>) being provided with a first groove (522a), the first groove (522a) and the inner wall of the accommodation space (<NUM>) forming a first gas chamber, and both of the first gas inlet hole (<NUM>) and the second gas inlet hole (<NUM>) being communicated with the first gas chamber.