阅读说明：本技术 一种阻挡等离子体反流的进气结构 (Prevent palirrhea air intake structure of plasma ) 是由 刘海洋 刘小波 胡冬冬 张军 程实然 李娜 吴志浩 许开东 于 2020-05-20 设计创作，主要内容包括：本发明涉及一种阻挡等离子体反流的进气结构,将进气结构的进气导向体本体分成三部分,分别为顶部进气导向体、若干分层进气导向组以及底部进气导向体,其中,顶部进气导向体设置在进气法兰与进气喷嘴交接处,底部进气导向体设置在进气喷嘴底部,若干分层进气导向组设置在顶部进气导向体、底部进气导向体之间；在进气喷嘴的封闭端圆周壁上对称开设两个出气口,出气口与进气喷嘴的封闭端之间形成锐角,同时底部进气导向体与出气口贯通；通过将导气通道设计成弓形,可以减小腔体内等离子体回流及阻止回流气体接触高功率射频部件,避免了进气导向体内气体通道与射频件近距离连通,同时避免垂直方向上的气体通道距离足够电子运动点火,损坏进气结构。(The invention relates to a plasma backflow prevention air inlet structure, which is characterized in that an air inlet guide body of the air inlet structure is divided into three parts, namely a top air inlet guide body, a plurality of layered air inlet guide groups and a bottom air inlet guide body, wherein the top air inlet guide body is arranged at the joint of an air inlet flange and an air inlet nozzle, the bottom air inlet guide body is arranged at the bottom of the air inlet nozzle, and the layered air inlet guide groups are arranged between the top air inlet guide body and the bottom air inlet guide body; two air outlets are symmetrically formed in the circumferential wall of the closed end of the air inlet nozzle, an acute angle is formed between each air outlet and the closed end of the air inlet nozzle, and meanwhile, the air inlet guide body at the bottom is communicated with the air outlets; by designing the gas guide channel into a bow shape, plasma backflow in the cavity can be reduced, backflow gas is prevented from contacting the high-power radio frequency part, the gas channel in the gas inlet guide body is prevented from being communicated with the radio frequency part in a short distance, and meanwhile, the gas channel in the vertical direction is prevented from being ignited by enough electronic motion to damage the gas inlet structure.)

1. The utility model provides a block palirrhea air inlet structure of plasma, including reaction chamber, at reaction chamber's top installation coupling window, coupling window central point puts installation air intake nozzle (50), the gas outlet is seted up to the blind end of air intake nozzle (50), the embedded air inlet guide body of establishing in air intake nozzle (50), air inlet flange (52) cover is established at air intake nozzle (50) open end, process gas is behind air inlet flange (52), reach air inlet nozzle (50) inside through air inlet guide body, in the gas outlet entering reaction chamber through air inlet nozzle (50), its characterized in that:

the air inlet guide body comprises a top air inlet guide body (90), a plurality of layered air inlet guide groups and a bottom air inlet guide body (120), wherein the top air inlet guide body (90) is arranged at the joint of the air inlet flange (52) and the air inlet nozzle (50), the bottom air inlet guide body (120) is arranged at the bottom of the air inlet nozzle (50), and the plurality of layered air inlet guide groups are arranged between the top air inlet guide body (90) and the bottom air inlet guide body (120);

two air outlets are symmetrically formed in the circumferential wall of the closed end of the air inlet nozzle (50), an acute angle is formed between each air outlet and the closed end of the air inlet nozzle (50), and meanwhile, the air inlet guide body (120) at the bottom is communicated with the air outlets.

2. A plasma flood resistant gas inlet structure according to claim 1, further comprising:

the layered air inlet guide group comprises a first layered air inlet guide body (100) and a second layered air inlet guide body (110) which are sequentially overlapped from top to bottom;

the first layered air inlet guide body (100) is cylindrical, the center of the first layered air inlet guide body protrudes upwards to form a first air inlet table (102), a plurality of through first air inlet grooves (101) are formed along the circumferential axial direction of the first layered air inlet guide body (100) by taking the center of the first air inlet table (102) as the circle center,

the second layered air inlet guide body (110) is also cylindrical, the center of the second layered air inlet guide body protrudes upwards to form a second air inlet table (112), and a plurality of through second air inlet grooves (111) are formed in the axial direction of the second layered air inlet guide body (110) along the circumference of the second air inlet table (112) by taking the center of the second air inlet table (112) as the center of a circle;

when the first layered air inlet guide body (100) is arranged above the second layered air inlet guide body (110) or the second layered air inlet guide body (110) is arranged above the first layered air inlet guide body (100), a first air inlet channel (131) is formed between the first layered air inlet guide body (100) and the second layered air inlet guide body (110), and the first air inlet channel (131) can be communicated with the adjacent first air inlet groove (101) or the second air inlet groove (111).

3. A plasma flood resistant gas inlet structure according to claim 2, wherein:

the top air inlet guide body (90) comprises a cylindrical structure, the center of the cylindrical structure is used as the circle center, a plurality of penetrating top air inlet grooves (91) are formed in the axial direction, and the inner diameter of a circular ring formed by the plurality of top air inlet grooves (91) is larger than or equal to the diameter of the first air inlet table (102);

the bottom of the top air inlet guide body (90) expands outwards along the circumference to form an insulating shaft shoulder (92), the cylindrical structure of the top air inlet guide body (90) is embedded in the air inlet flange (52), and the insulating shaft shoulder (92) is embedded in the air inlet nozzle (50);

when the top air inlet guide body (90) is arranged above the first layered air inlet guide body (100), a first air inlet channel (131) is formed between the top air inlet guide body and the first layered air inlet guide body, and the top air inlet groove (91) is communicated with the first air inlet groove (101) through the first air inlet channel (131).

4. A plasma flood resistant gas inlet structure according to claim 3, wherein:

the bottom air inlet guide body (120) is cylindrical, the center of the bottom air inlet guide body protrudes upwards to form a third air inlet table (122), and the part of the bottom air inlet guide body (120) which is not protruded forms an annular shaft shoulder (121);

when the bottom air inlet guide body (120) is positioned below the second layered air inlet guide body (110), a second air inlet channel (132) is formed between the bottom air inlet guide body (120) and the second layered air inlet guide body (110), and the second air inlet channel (132) is communicated with the second air inlet groove (111).

5. A plasma flood resistant gas inlet structure according to claim 1, further comprising: the air inlet guide body is made of an insulating material, and is made of plastic, ceramic or quartz.

Technical Field

The invention relates to a gas inlet structure for preventing plasma from flowing backwards, and belongs to the technical field of semiconductor etching.

Background

In a semiconductor integrated circuit manufacturing process, etching is one of the most important processes, wherein plasma etching is one of the commonly used etching methods, and usually etching occurs in a vacuum reaction chamber, which usually includes an electrostatic chuck for carrying and adsorbing a wafer, an rf load, and cooling the wafer. At present, in the manufacturing process of semiconductor devices and the like, an electrostatic adsorption chuck is usually placed on a base in the middle of a vacuum processing chamber, a wafer is positioned on the upper surface of the electrostatic adsorption chuck, radio frequency is applied in an electrode at the top of the base, so that plasma of introduced reaction gas is formed in the processing chamber to process the wafer, in the etching process of some non-volatile metal materials, the plasma is accelerated to reach the surface of the metal material under the action of bias voltage, metal particles sputtered from the surface of the etched material are attached to all exposed surfaces in the cavity, including the inner wall of the cavity and a coupling window at the top of the cavity, so as to cause pollution, in order to solve the pollution, cleaning gas needs to be introduced into the cavity, radio frequency power is loaded at the top to ionize the cleaning gas and take away the pollution particles, and as the cavity is grounded in the whole cleaning process, and the top coupling window is made of an insulating material, so that the top radio frequency loads radio frequency power to excite plasma in the cleaning process, the grounded cavity can be cleaned by active plasma, the cleaning effect on the dielectric window is almost not achieved, the pollutants are more seriously overlapped along with the time, and the phenomenon that the wafer is polluted by falling deposits occurs.

In order to clean the coupling window thoroughly, an electrostatic shielding piece can be adopted, and the Faraday shielding is used in a plasma processing chamber to reduce the erosion of plasma to cavity materials; however, when the radio frequency power is gradually increased, the cleaning gas enters the cavity through the gas inlet channel, and is ionized in the cavity under the action of the radio frequency power supply to form plasma flow, the plasma flow can return to the gas inlet channel through the gas inlet hole at the same time, and the gas inlet channel is too close to the radio frequency power point, so that ignition is caused in the gas inlet channel, the gas inlet guide body is damaged, and the gas inlet guide body cannot be used.

Disclosure of Invention

The invention provides a gas inlet structure for preventing plasma from flowing backwards, which can reduce plasma backflow in a cavity and prevent backflow gas from contacting a high-power radio frequency part by designing a gas guide channel into an arc shape, thereby avoiding the gas channel in a gas inlet guide body from being communicated with the radio frequency part at a short distance and avoiding the gas channel in the vertical direction from being enough for electronic motion ignition to damage the gas inlet structure.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a gas inlet structure for preventing plasma from flowing reversely comprises a reaction chamber, a coupling window is arranged at the top of the reaction chamber, a gas inlet nozzle is arranged at the center of the coupling window, a gas outlet is formed in the closed end of the gas inlet nozzle, a gas inlet guide body is embedded in the gas inlet nozzle, a gas inlet flange is sleeved at the open end of the gas inlet nozzle, process gas reaches the interior of the gas inlet nozzle through the gas inlet guide body after passing through the gas inlet flange and enters the reaction chamber through the gas outlet of the gas inlet nozzle,

the air inlet guide body comprises a top air inlet guide body, a plurality of layered air inlet guide groups and a bottom air inlet guide body, wherein the top air inlet guide body is arranged at the joint of the air inlet flange and the air inlet nozzle, the bottom air inlet guide body is arranged at the bottom of the air inlet nozzle, and the layered air inlet guide groups are arranged between the top air inlet guide body and the bottom air inlet guide body;

two air outlets are symmetrically formed in the circumferential wall of the closed end of the air inlet nozzle, an acute angle is formed between each air outlet and the closed end of the air inlet nozzle, and meanwhile, the air inlet guide body at the bottom is communicated with the air outlets;

as a further preferred aspect of the present invention,

the layered air inlet guide group comprises a first layered air inlet guide body and a second layered air inlet guide body which are sequentially overlapped from top to bottom;

the first layered air inlet guide body is cylindrical, the center of the first layered air inlet guide body is upwards protruded to form a first air inlet table, a plurality of through first air inlet grooves are formed along the circumferential axial direction of the first layered air inlet guide body by taking the center of the first air inlet table as the circle center,

the second layered air inlet guide body is also cylindrical, the center of the second layered air inlet guide body protrudes upwards to form a second air inlet table, and a plurality of through second air inlet grooves are formed in the axial direction of the second layered air inlet guide body along the circumference of the second air inlet table by taking the center of the second air inlet table as the center of a circle;

when the first layered air inlet guide body is arranged above the second layered air inlet guide body or the second layered air inlet guide body is arranged above the first layered air inlet guide body, a first air inlet channel is formed between the first layered air inlet guide body and the second layered air inlet guide body, and the first air inlet channel is communicated with the adjacent first air inlet groove or the adjacent second air inlet groove;

as a further preferred aspect of the present invention,

the top air inlet guide body comprises a cylindrical structure, a plurality of penetrating top air inlet grooves are formed in the axial direction by taking the center of the cylindrical structure as the circle center, and the inner diameter of a ring formed by the top air inlet grooves is larger than or equal to the diameter of the first air inlet table;

the bottom of the top air inlet guide body expands outwards along the circumference to form an insulating shaft shoulder, the cylindrical structure of the top air inlet guide body is embedded in the air inlet flange, and the insulating shaft shoulder is embedded in the air inlet nozzle;

when the top air inlet guide body is arranged above the first layered air inlet guide body, a first air inlet channel is formed between the top air inlet guide body and the first layered air inlet guide body, and the top air inlet groove is communicated with the first air inlet channel through the first air inlet channel;

as a further preferred aspect of the present invention,

the bottom air inlet guide body is cylindrical, the center of the bottom air inlet guide body protrudes upwards to form a third air inlet table, and the part of the bottom air inlet guide body which is not protruded forms a circular shaft shoulder;

when the bottom air inlet guide body is positioned below the second layered air inlet guide body, a second air inlet channel is formed between the bottom air inlet guide body and the second layered air inlet guide body and communicated with the second air inlet channel;

as a further preferred aspect of the present invention,

the air inlet guide body is made of an insulating material, and is made of plastic, ceramic or quartz.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

the gas guide channel is designed into an arc shape, and the communication distance between the gas channel in the gas inlet guide body and the radio frequency part can be prolonged, so that the plasma backflow path in the reaction cavity is prolonged, and the backflow plasma is prevented from contacting the high-power radio frequency part;

the invention changes the traditional vertical gas guide channel, avoids the possibility that the gas channel in the vertical direction can form enough electronic movement ignition distance, thereby avoiding the possibility of damaging the gas inlet structure;

according to the invention, the insulating shaft shoulder is arranged on the contact part of the air inlet nozzle and the air inlet flange through the top air inlet guide body, so that the chance that the air in the air inlet flange and the air inlet nozzle directly faces is avoided, and the possibility of ignition caused by the backflow of plasma between the air inlet flange and the air inlet nozzle along with the improvement of radio frequency power is avoided.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic diagram of the overall structure of the prior art of the present invention;

FIG. 2 is a schematic view of an intake guide provided in the prior art of the present invention;

FIG. 3 is a schematic diagram of the overall structure of the preferred embodiment of the present invention;

FIG. 4 is a schematic structural view of a top intake guide according to a preferred embodiment of the present invention;

FIG. 5 is a schematic view of a first stratified charge director configuration in accordance with a preferred embodiment of the present invention;

FIG. 6 is a schematic structural view of a second stratified charge director in accordance with a preferred embodiment of the present invention;

fig. 7 is a sectional view of an intake passage inside an intake guide body according to a preferred embodiment of the present invention.

In fig. 1-2: 111 is an upper radio frequency matcher, 112 is a cavity cover, 113 is a coupling window, 114 is a coil, 115 is an air inlet flange, 116 is an air inlet nozzle, 117 is an air inlet direction, 51 is a central air inlet guide body, and 511, 512 and 513 are air guide channels;

in fig. 3-7: 50 is the air inlet nozzle, 52 is the air inlet flange, 90 is the top air inlet director, 91 is the top air inlet groove, 92 is insulating shaft shoulder, 100 is the first hierarchical air inlet director, 101 is the first air inlet groove, 102 is the first air inlet platform, 110 is the second hierarchical air inlet director, 111 is the second air inlet groove, 112 is the second air inlet platform, 120 is the bottom air inlet director, 121 is the shaft shoulder, 122 is the third air inlet platform, 131 is the first air inlet passageway, 132 is the second air inlet passageway.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

As shown in fig. 1, in a conventional etching system, an electrostatic chuck is disposed at a center of a reaction chamber, a wafer is disposed on a surface of the electrostatic chuck, a chamber cover 112 is disposed at a top of the reaction chamber, a coupling window 113 is mounted on the chamber cover 112, and a central air inlet device is mounted at a center of the coupling window 113, as can be seen from fig. 1, the system includes an air inlet nozzle 116, a central air inlet guide 51 and an air inlet flange 115, wherein the air inlet flange 115 is made of a metal material and is connected to an upper rf matcher 111; a coil 114 is arranged on the upper surface of the coupling window 113 outside the central air inlet device and is also connected to the upper radio frequency matcher 111;

in the prior art, as shown in fig. 2, a central air inlet guide body 51 is provided with a whole air guide system composed of an air guide channel 511, an air guide channel 512 and an air guide channel 513 on the surface of the central air inlet guide body 51, when a reaction chamber is subjected to a process operation, a circuit of an upper radio frequency matcher 111 connected to a coil 114 is conducted, a process gas enters through an air inlet flange 115, an air inlet direction is shown as 117 in fig. 1, the process gas reaches the inside of an air inlet nozzle 116 through the air guide system on the surface of the central air inlet guide body 51, and then enters the inside of the reaction chamber through an air outlet of the air inlet nozzle 116 to form plasma, so as to etch a wafer;

when the system is cleaned, the upper radio frequency matcher 111 closes the connecting coil 114, opens a passage connected to the gas inlet flange 115, and simultaneously, cleaning gas enters through the gas inlet flange 115, reaches the inside of the gas inlet nozzle 116 through the gas guide system on the surface of the central gas inlet guide body 51, and then enters the inside of the reaction chamber through the gas outlet hole of the gas inlet nozzle 116, and is ionized into cleaning plasma gas flow formed inside the chamber, so as to clean the inside and upper regions of the chamber; however, as is apparent from fig. 1, the gas inlet flange 115 is connected to a high power cleaning rf, and the gas guide 513 on the central gas inlet guide 51 is vertical, the plasma formed inside the chamber returns to the inside of the gas guide 513 through the gas outlet at the bottom of the gas inlet nozzle 116, and the gas inlet flange 115 is closely connected to the upper portion of the gas inlet guide, so that the gas guide 513 is in communication with the gas inlet flange 11552, and the gas is discharged in this region, resulting in high charge formation inside the gas guide 513 and burnout of the gas inlet guide.

Based on the mentioned defects, the application provides a gas inlet structure for preventing plasma from reflowing, which comprises a reaction chamber, a coupling window is installed at the top of the reaction chamber, the central position of the coupling window is provided with a gas inlet nozzle 50, the closed end of the gas inlet nozzle 50 is provided with a gas outlet, a gas inlet guide body is embedded in the gas inlet nozzle 50, the gas inlet flange 52 is sleeved at the open end of the gas inlet nozzle 50, process gas reaches the inside of the gas inlet nozzle 50 through the gas inlet guide body after passing through the gas inlet flange 52 and enters the reaction chamber through the gas outlet of the gas inlet nozzle 50, the gas inlet guide body comprises a top gas inlet guide body 90, a plurality of layered gas inlet guide groups and a bottom gas inlet guide body 120, wherein the top gas inlet guide body 90 is arranged at the joint of the gas inlet flange 52 and the gas inlet nozzle 50, the bottom gas inlet guide body 120 is arranged at the bottom of the gas inlet nozzle 50, and the plurality of layered gas inlet guide groups are arranged at the top gas inlet guide body 90, Between the bottom intake guides 120; two air outlets are symmetrically arranged on the circumferential wall of the closed end of the air inlet nozzle 50, an acute angle is formed between the air outlets and the closed end of the air inlet nozzle 50, and meanwhile, the bottom air inlet guide body 120 is communicated with the air outlets.

Decomposing the structure of the air inlet guide body into a top air inlet guide body 90, a plurality of layered air inlet guide groups and a bottom air inlet guide body 120, so that the communication distance between the gas flow channel in the air inlet guide body and the upper radio frequency matcher is prolonged, and the reflux path of the plasma in the reaction chamber is correspondingly prolonged when the plasma reflows; meanwhile, because the channel in the decomposed air inlet guide body is not a vertical gas channel, the possibility that the gas channel in the vertical direction can form enough electronic motion ignition distance is avoided, and the possibility of damaging an air inlet structure is avoided.

Example (b):

one of the preferred embodiments of the gas inlet structure provided herein with respect to the barrier to plasma flashback is shown in figure 3,

wherein, as shown in fig. 5, the first layered air inlet guide body 100 is cylindrical, the center thereof protrudes upwards to form a first air inlet table 102, a plurality of first air inlet grooves 101 are arranged along the circumference of the first layered air inlet guide body 100 by taking the center of the first air inlet table 102 as the center of a circle,

as shown in fig. 6, the second layered air inlet guide body 110 is also cylindrical, the center of the second layered air inlet guide body protrudes upwards to form a second air inlet table 112, and a plurality of second air inlet grooves 111 are formed in the second layered air inlet guide body 110 along the circumference of the second air inlet table 112 with the center of the second air inlet table 112 as the center of a circle;

as shown in fig. 4, the top air inlet guide body 90 includes a cylindrical structure, and a plurality of top air inlet slots 91 are formed through the center of the cylindrical structure, and the inner diameter of a ring formed by the plurality of top air inlet slots 91 is greater than or equal to the diameter of the first air inlet table 102; the bottom air inlet guide body 120 is cylindrical, the center of the bottom air inlet guide body protrudes upwards to form a third air inlet table 122, and the part of the bottom air inlet guide body 120 which is not protruded forms a circular shaft shoulder 121;

when the first layered air intake guiding body 100 is installed above the second layered air intake guiding body 110 or the second layered air intake guiding body 110 is installed above the first layered air intake guiding body 100, a first air intake channel 131 is formed between the first layered air intake guiding body 100 and the second layered air intake guiding body 110, and the first air intake channel 131 is respectively communicated with the adjacent first air intake groove 101 or the second air intake groove 111; when the top intake guide 90 is installed above the first layered intake guide 100, a first intake passage 131 is also formed therebetween, and the top intake groove 91 and the first intake groove 101 are communicated through the first intake passage 131; when the bottom intake guide 120 is located below the second stratified intake guide 110, a second intake passage 132 is formed between the bottom intake guide 120 and the second stratified intake guide 110, and the second intake passage 132 is communicated with the second intake groove 111.

In this embodiment, three sets of layered inlet guide groups are provided, each of which includes a first layered inlet guide body 100 and a second layered inlet guide body 110 that are sequentially stacked from top to bottom; that is, the inlet guide body in the embodiment sequentially arranges the top inlet guide body 90, the first layered inlet guide body 100, the second layered inlet guide body 110, and the bottom inlet guide body 120 from top to bottom, fig. 7 shows the inlet channel trend schematic diagram of the preferred embodiment, after passing through the inlet flange 52, the gas enters the first inlet channel 131 through the top inlet channel 91, and then sequentially passes through the first inlet channel 101, the first inlet channel 131, the second inlet channel 111, the first inlet channel 131, the first inlet channel 101, the first inlet channel 131, the second inlet channel 111, and the second inlet channel 132, the second gas inlet channel 132 is communicated with the gas outlet of the gas inlet nozzle 50, and the gas is finally discharged through the gas outlet;

when plasma airflow in the reaction chamber flows back through an air outlet at the bottom of the air inlet nozzle 50 and enters an arched air inlet channel in the air inlet guide body, the area and the probability of the plasma airflow impacting on a solid wall in the air inlet guide body in the arched air inlet channel are greatly increased, electrons gradually disappear along with collision energy, and a path communicated with a high-power component cannot be formed because an area near the air inlet flange 52 with radio-frequency power is insulated and uncharged, so that the air inlet guide body is protected from being damaged by high heat and high radio frequency;

as can be seen from fig. 7, the air inlet channel inside the air inlet guide body provided in this embodiment is arcuately arranged in the cross-sectional view, because of the structural design of the air inlet channel in the air inlet structure, and the positions of the air outlets of the air inlet nozzle 50 are combined at the same time, two air outlets are symmetrically arranged on the circumferential wall of the closed end of the air inlet nozzle 50, an acute angle is formed between the air outlets and the closed end of the air inlet nozzle 50, and the bottom air inlet guide body 120 is communicated with the air outlets, so that the second air inlet channel 132 is far away from the air outlets of the air inlet nozzle 50, and the process and cleaning gases uniformly flow in the second air inlet channel 132 through the tortuous air inlet path before entering the reaction chamber from the air outlets at the bottom of the air inlet nozzle 50, thereby greatly reducing the influence of the complex air inlet path on the process and cleaning process results;

since the top inlet guide body 90, the layered inlet guide group and the bottom inlet guide body 120 are embedded in the inlet nozzle 50 and are in clearance fit with the inlet nozzle 50, a gap is formed on the matching surface, the existence of the gap means that a gas passage between the inlet flange 52 and the inlet nozzle 50 has a space facing directly, so that the radio frequency power loaded on the inlet flange 52 is limited, and as the radio frequency power is increased, ignition is easily caused between the inlet flange 52 and the inlet nozzle 50 due to the reverse flow of plasma, so that as shown in fig. 4, the bottom of the top inlet guide body 90 expands outwards along the circumference to form an insulating shoulder 92, the cylindrical structure of the top inlet guide body 90 is embedded in the inlet flange 52, and the insulating shoulder 92 is embedded in the inlet nozzle 50; the presence of the insulating shoulder 92 eliminates the opportunity for the gas in the inlet flange 52 to directly face the gas in the inlet nozzle 50, thereby eliminating the possibility of sparking between the inlet flange 52 and the inlet nozzle 50 due to plasma backflow as the rf power is increased.

Therefore, the gas guide channel is designed into an arc-shaped or other non-vertical channel taking the preferred embodiment as an example, plasma backflow in the reaction cavity can be reduced, backflow gas can be prevented from contacting the high-power radio frequency part, the gas channel in the gas inlet guide body is prevented from being communicated with the radio frequency part in a short distance, and meanwhile, the gas channel in the vertical direction is prevented from being far enough from the electron motion to ignite and damage the gas inlet structure.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "and/or" as used herein is intended to include both the individual components or both.

The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.