TW202127498A - Plasma processing system having opening-and-closing faraday assembly, and opening-and-closing faraday assembly thereof - Google Patents

Abstract

A plasma processing system having an opening-and-closing Faraday assembly, and an opening-and-closing Faraday assembly thereof are disclosed. The opening-and-closing Faraday assembly comprises a Faraday layer, and the Faraday layer comprises a knob, a radio frequency access block, a lift mechanism, and a plurality of annular sector pieces. The annular sector pieces are driven by the knob to synchronously rotate around a first positioning element disposed on respective sectors, and are limited in rotation amplitude between a first limit position and a second limit position by guide connection of a second positioning element and a guide chute on the knob. When each annular sector piece is located at the first limit position, the Faraday layer is in a closed state. When each annular sector piece is located at the second limit position, the Faraday layer is in an open state, and in this case, a central area on an inner side of the knob is completely exposed. Therefore, the present invention achieves thorough cleaning of a coupling window by controlling the Faraday layer to open and close in etching and cleaning processes. In addition, the Faraday layer is in the open state during the etching process, and does not affect the etching process.

Description

Plasma processing system with opening legal Raday element and opening legal Raday element

The invention relates to a plasma processing system, in particular to a plasma processing system with a raday cleaning element for opening, and belongs to the technical field of semiconductor integrated circuit manufacturing.

In the semiconductor integrated circuit manufacturing process, etching is one of the most important processes. Plasma etching is one of the commonly used etching methods. The etching usually takes place in a vacuum reaction chamber. Usually, the vacuum reaction chamber includes static electricity. The adsorption chuck is used to carry the functions of adsorbing wafers, RF loads and cooling wafers. At present, in the manufacturing process of semiconductor devices, etc., electrostatic adsorption chucks are usually placed on a susceptor in the middle of a vacuum processing chamber. The wafer is located on the upper surface of the electrostatic adsorption chuck, and a radio frequency is applied to the electrode on the top of the susceptor, so that plasma of the introduced reaction gas is formed in the processing chamber to process the wafer.

At present, in the etching process of some non-volatile metal materials, the plasma is accelerated to the surface of the metal material under the action of the bias voltage, and the metal particles sputtered from the surface of the etching material will adhere to all exposed surfaces in the cavity. Including the inner wall of the cavity and the coupling window on the top of the cavity, causing pollution. In order to solve the pollution, it is necessary to pass the cleaning gas into the cavity, and load the radio frequency power at the top to ionize the cleaning gas, take away these polluting particles, and clean the whole During the process, since the cavity is grounded and the top coupling window is made of insulating material, RF power is applied to the top to excite the plasma during the cleaning process. The active plasma will clean the grounded cavity, but it has almost no cleaning effect on the coupling window. As time goes by, the contaminant stack becomes more serious, and the phenomenon that the deposit falls off and contaminates the wafer.

In order to thoroughly clean the coupling window, a Faraday layer can be used. The use of the Faraday layer in the plasma processing chamber can reduce the erosion of the cavity material by the plasma, but there is still some plasma that can pass through the slits between the Faraday layers to contaminate the coupling window. The Faraday layer is placed between the RF coil and the coupling window to reduce the erosion of the cavity wall by ions induced by the RF electric field. This shield can be grounded or floating. When the Faraday shield is grounded, the intensity of the radio frequency electric field is reduced due to the reduced capacitive coupling, which makes it very difficult to initiate plasma discharge. When the plasma is a floating design, it will not excessively hinder the excitation of the plasma, but it is not very effective in preventing the plasma from eroding the cavity.

In view of the shortcomings of the prior art, the present invention provides an opening method pull element, which is installed outside the coupling window of a plasma processing system. When cleaning, each ring segment constituting the opening method pull element is in a closed state and can cover the coupling The area where the window is in contact with the plasma. At this time, the inner arc surface of each ring segment is on the concentric circle a, and the outer arc surface of each ring segment is on the concentric circle b; The ring segments of the open-ended pull element are in an open state, and the middle coil on the open-ended pull element can be completely exposed. At this time, the first section of each ring segment can be tangent to the maximum open inscribed circle. The diameter of the largest open inscribed circle is larger than the outer diameter of the middle coil. It can be seen from this that the Raday element of the open method of the present invention can effectively avoid adverse effects on wafer etching, and when cleaning the coupling window, the Faraday layer can be used to completely clean the coupling window.

In order to realize the above technical solutions, the present invention will adopt the following technical solutions:

An open-leg pull element, including a Faraday layer, the Faraday layer including a knob, a radio frequency access block, a lifting mechanism that drives the radio frequency access block to move, and a plurality of ring segments that are evenly distributed on the outer side of the O axis and arranged in separate bodies; in:

The knob has an annular shape as a whole, and is rotatably arranged concentrically on the outer side of the O axis, and is equidistantly provided along the annular surface of the knob with a number of guide chutes matching the number of ring segments;

Each ring segment includes an inner circular arc surface, an outer circular arc surface, and a first side profile and a second side profile that connect the same sides of the inner circular arc surface and the outer circular arc surface respectively; at the same time, each ring The fan pieces are each provided with two positioning members on the fan surface close to the outer arc surface; the two positioning members are respectively a first positioning member and a second positioning member;

Driven by the knob, each ring segment can rotate synchronously around the first positioning member provided on the respective fan surface, and the second positioning member is connected to the guide chute on the knob to limit the rotation range to the first limit position Between and the second extreme position;

When each ring segment is in the first limit position, the Faraday layer is in a closed state. At this time, the inner arc surface of each ring segment is on the circumference of the concentric circle a outside the O axis and is arranged equidistantly. The outer arc surface of is on the circumference of the concentric circle b outside the O axis and is arranged equidistantly, and the inner diameter of the concentric circle a is smaller than the inner diameter of the concentric circle b;

When each ring segment is in the second limit position, the Faraday layer is in the open state. At this time, the first side profile of each ring segment can be tangent to the maximum open inscribed circle, and the inner side of the knob corresponds to the maximum open inscribed circle The area is completely exposed;

The radio frequency access block is connected with the power output end of the lifting mechanism;

Driven by the power of the lifting mechanism, the radio frequency access block can move toward the Faraday layer to electrically connect with the inner arc surface of each ring segment of the Faraday layer in the closed state, or move away from the Faraday layer to be in the open state. The Faraday layer is separated.

Further, the guide chute is a strip groove.

Further, the strip-shaped groove is arranged obliquely.

Further, the first side profile and the second side profile are both straight profiles; or the first side profile is a convex arc profile, and the second profile is a concave arc profile. noodle.

Further, the lifting mechanism includes a cylinder, a cylinder adapter plate and a cylinder adapter insulating rod; the power output end of the cylinder is sequentially fixed by the cylinder adapter plate, the cylinder adapter insulating rod and the radio frequency access block.

Further, the first positioning member and the second positioning member are both pins.

Another technical objective of the present invention is to provide a plasma processing system with an opening method Raday element, including a coupling window, and the opening method Raday element as described above is arranged outside the coupling window;

Each ring segment is positioned and connected with the coupling window through the first positioning member provided on the respective segment surface;

The coupling window is provided with a rotating positioning surface at a position corresponding to the outer edge of the knob; the knob can be rotated around the O axis through the positioning of the rotating positioning surface.

Further, a coil structure is provided on the outside of the open-ended Raday element, including a middle coil; the middle coil is orthographically projected on the inner area of the knob, and the outer diameter of the middle coil is not greater than the diameter of the largest open inscribed circle;

When each ring segment is in the first limit position, the inner arc surface of each ring segment in the closed state is connected to the Faraday RF power supply through the radio frequency access block;

When each ring segment is at the second limit position, the middle coil is completely exposed on the surface of the coupling window; both the middle coil and the edge coil are connected to the coil radio frequency power supply.

Further, the coil structure further includes an edge coil that is independently arranged relative to the middle coil; the edge coil can be orthographically projected on the inner area of the knob;

When each ring segment is in the second limit position, the middle coil and the edge coil are completely exposed on the surface of the coupling window; the middle coil and the edge coil are both connected to the coil radio frequency power supply.

Further, the first positioning member is a first pin; the coupling window is provided with a pin hole at a position corresponding to the first pin on each ring segment; each ring segment passes through the first pin provided on the respective fan surface and Each pin hole on the coupling window is connected in a one-to-one correspondence;

A middle fixing hole is arranged at the middle position of the coupling window; the middle fixing hole is equipped with a ceramic air inlet nozzle, and the air outlet part of the ceramic air inlet nozzle is equipped with a nozzle.

Further, it also includes a reaction chamber; the upper end of the reaction chamber is opened; and the open end of the reaction chamber is sealed with a cavity cover; the middle of the cavity cover is provided with a window matching the coupling window;

A susceptor is arranged in the reaction chamber; the top of the susceptor is fixedly connected with the bias electrode, the bias electrode is directly opposite to the nozzle, and the top surface of the bias electrode adsorbs the wafer;

A shielding box is fixed on the top of the reaction chamber, the cross-section of the shielding box is in a U-shaped structure, and the shielding box is in a sealed connection with the cavity cover;

The radio frequency access block and the lifting mechanism are both arranged in the shielding box; one end of the lifting mechanism is fixed to the top of the shielding box, and the other end of the lifting mechanism is fixed to the radio frequency access block.

Another objective of the present invention is to provide a method based on a plasma processing system with a Raday element having an opening method, which includes two processes, namely a coupling window cleaning process and a wafer etching process, wherein,

The specific steps of the wafer etching process are:

1.1) Place the wafer above the bias electrode in the reaction chamber;

1.2) The cylinder goes up to separate the RF access block from the Faraday layer;

1.3) Rotate the knob to open the Faraday layer to the second limit position; at this time, the first side profile of each ring segment constituting the Faraday layer can be tangent to the maximum open inscribed circle, and is in line with the maximum open inscribed circle The middle coil of the pair is directly opposite to the coupling window;

1.4) Pass the process gas into the reaction chamber through the ceramic gas inlet nozzle; pass the RF power supply that meets the demand into the middle coil;

1.5) Plasma etching on the surface of the wafer;

1.6) After the etching process is finished, stop the process gas flow into the reaction chamber and stop the power supply to the middle coil, and vacuumize the reaction chamber;

The specific steps of the coupling window cleaning process are:

2.1) Place the substrate sheet above the bias electrode in the reaction chamber;

2.2) Rotate the knob to make the Faraday layer in the closed state. At this time, the inner arc surface of each ring segment is on the circumference of the concentric circle a outside the O axis, and the outer arc surface of each ring segment is outside the O axis On the circumference of the concentric circle b;

2.3) When the cylinder goes down, press the RF access block to the position where each ring segment of the Faraday layer in the closed state is close to the inner circular arc surface, so that the RF access block is conductively connected to each ring segment;

2.4) Purge the cleaning gas into the reaction chamber through the ceramic gas inlet nozzle;

2.5) Access to the Faraday layer with RF power that meets the requirements through the RF access block;

2.6) After cleaning is completed, stop supplying cleaning gas to the reaction chamber and stop supplying power to the Faraday layer, and vacuumize the reaction chamber.

According to the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

The opening method pull element of the present invention is installed outside the coupling window of the plasma processing system. During cleaning, the ring segments constituting the opening method pull element are in a closed state, which can cover the area where the coupling window is in contact with the plasma , At this time, the inner arc surface of each ring segment is on the concentric circle a, and the outer arc surface of each ring segment is on the concentric circle b; The fan is in the open state, which can completely expose the middle coil located on the open element. At this time, the first section of each ring fan can be tangent to the maximum open inscribed circle, and the diameter of the maximum open inscribed circle is greater than The outer diameter of the middle coil. It can be seen from this that the Raday element of the open method of the present invention can effectively avoid adverse effects on wafer etching, and when cleaning the coupling window, the Faraday layer can be used to completely clean the coupling window. That is, the present invention is beneficial to solve the problem of the reduction of the radio frequency electric field intensity caused by the traditional Faraday shielding unit, is beneficial to cleaning the coupling window, and does not affect the intensity of the radio frequency electric field, and is convenient for operation.

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, and in no way serves as any limitation to the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention. Unless specifically stated otherwise, the relative arrangement, calculation formulas and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The technologies, methods, and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be regarded as part of the authorization specification. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiment may have different values.

For ease of description, spatial relative terms can be used here, such as "above", "above", "above the surface", "above", etc., to describe as shown in the figure Shows the spatial positional relationship between one device or feature and other devices or features. It should be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the drawing is turned upside down, then a device described as "above other devices or structures" or "above other devices or structures" will then be positioned as "below the other devices or structures" or "on Under other devices or structures". Thus, the exemplary term "above" may include both orientations "above" and "below". The device can also be positioned in other different ways (rotated by 90 degrees or in other orientations).

The present invention discloses a Faraday element 14 including a Faraday layer. As shown in Figures 1 to 5, the Faraday layer includes a knob 10, a radio frequency access block 22, and a lifting mechanism that drives the radio frequency access block 22 to move. , A plurality of ring segments 14-1 evenly distributed on the outside of the O axis and arranged separately; the material of the segments is preferably copper or aluminum, wherein: the knob 10 is in the shape of a ring as a whole, and is rotatably arranged concentrically on the On the outer side of the O axis, and along the annular surface of the knob 10, there are equidistant guide chutes 11 with a number matching the number of the ring segments 14-1; The center is symmetric and evenly distributed, and its center line is tangent to the largest open inscribed circle opened by the Faraday layer. The material of the knob 10 is preferably an insulating material ULTEM-1000, the rotation center of the knob 10 is the central axis o axis of the coupling window 7, and the rotation positioning surface 8 is the rotation positioning surface 8 provided on the edge of the coupling window 7. The power of the knob 10 The source can be manual, or it can be driven by an external electrode or driven by a rotating cylinder 19, which is not described in the present invention.

Each ring segment 14-1 includes an inner circular arc surface 14-1b, an outer circular arc surface 14-1d, and a first connecting the same sides of the inner circular arc surface 14-1b and the outer circular arc surface 14-1d. Side profile 14-1a, second side profile 14-1c; to form Faraday layers of different shapes, ring segments 14-1 of different shapes can be used, namely, the first side profile 14-1a and the second side profile 14-1a of the present invention The side profile 14-1c can be as shown in Figure 5, that is, the first side profile 14-1a is a convex curved profile, and the second side profile 14-1c is a concave curved profile. , It can also be a straight profile. At the same time, each ring segment 14-1 is respectively provided with two positioning members on the fan surface close to the outer arc surface 14-1d; the two positioning members are the first positioning member and the second positioning member respectively; The positioning member and the second positioning member are both pins, and the first positioning member and the second positioning member are corresponding to the first pin 12 and the second pin 13.

Each ring segment 14-1 is driven by the knob 10 to rotate synchronously around the first positioning member provided on the respective fan surface, and the rotation is restricted by the guiding connection between the second positioning member and the guide chute 11 on the knob 10 The amplitude is between the first limit position and the second limit position; in the present invention, the guide chute 11 is a strip groove, and the strip groove is inclined.

When each ring segment 14-1 is at the first limit position, the Faraday layer is in a closed state. At this time, the inner circular arc surface 14-1b of each ring segment 14-1 is on the circumference of the concentric circle a outside the O axis. The outer circular arc surface 14-1d of each ring segment 14-1 is on the circumference of the concentric circle b outside the O axis and is arranged equidistantly, and the inner diameter of the concentric circle a is smaller than the inner diameter of the concentric circle b. path;

When each ring segment 14-1 is in the second limit position, the Faraday layer is in an open state. At this time, the first side profile 14-1a of each ring segment 14-1 can be tangent to the maximum open inscribed circle, and the knob 10 The inner side and the area corresponding to the largest open inscribed circle are completely exposed;

The radio frequency access block 22 is connected to the power output end of the lifting mechanism; in the present invention, the lifting mechanism includes a cylinder 19, a cylinder adapter plate 20, and a cylinder adapter insulating rod 21; the power output end of the cylinder passes through the cylinder adapter plate 20 in turn , The cylinder transfer insulating rod 21 and the radio frequency access block 22 are fixed.

Driven by the power of the lifting mechanism, the radio frequency access block 22 can move toward the Faraday layer to electrically connect with the inner arc surface 14-1b of each ring segment 14-1 of the Faraday layer in the closed state, or away from the Faraday layer Move to separate from the open Faraday layer.

Applying the above-mentioned opening method Raday element 14 to a plasma processing system, the resulting plasma processing system with opening method Raday element 14 includes the coupling window 7. In the present invention, the material of the coupling window 7 is generally ceramic. Located directly above the reaction chamber 1 and the chamber cover 6, an air inlet nozzle 9 is installed in the middle part through a fixed hole in the middle part, and the gas outlet part of the ceramic air inlet nozzle 16 is equipped with a nozzle to provide a process for the process in the chamber Gas/cleaning gas, the reaction chamber 1 has a bias electrode 4 and a wafer 5 directly above the bias electrode 4; a coil structure is installed above the coupling window 7. The coil is a three-dimensional coil 17, and the three-dimensional coil 17 includes The center coil and the edge coil are two independent parts. Both the center coil and the edge coil are coupled by two single three-dimensional coils. Each single three-dimensional coil has 2 layers, 3 layers or even more layers in height. 2 turns, 3 turns or even more turns. One end of the two single three-dimensional coils is connected together to connect to the external radio frequency device, and the other end is also connected to ground; The middle layer of the coil 17. At this time, each ring segment 14-1 is positioned and connected to the coupling window 7 through the first positioning member provided on the respective fan surface; the coupling window 7 is provided with a rotary positioning surface 8 at a position corresponding to the outer edge of the knob 10; 10 can be rotated around the O axis by the positioning of the rotating positioning surface 8. The three-dimensional coil 17 is orthographically projected on the inner area of the knob 10, and the outer diameter of the three-dimensional coil 17 is not greater than the diameter of the largest open inscribed circle; that is, both the middle coil and the edge coil can be orthographically projected on the outer area of the knob 10, and The outer diameter of the edge coil is not greater than the diameter of the largest open inscribed circle.

When each ring segment 14-1 is in the first limit position, the inner arc surface 14-1b of each ring segment 14-1 in the closed state is connected to the Faraday radio frequency power supply through the radio frequency access block 22;

When each ring segment 14-1 is in the second limit position, the three-dimensional coil 17 is completely exposed on the surface of the coupling window 7; the middle coil and the edge coil are both connected to the coil radio frequency power supply.

The first positioning member is a first pin 12; the coupling window 7 is provided with a pin hole 15 at a position corresponding to the first pin 12 on each ring segment 14-1; each ring segment 14-1 passes through its respective fan surface The first pins 12 provided on the above are connected to each pin hole 15 on the coupling window 7 in a one-to-one correspondence;

Further, it also includes a reaction chamber 1; the upper end of the reaction chamber 1 is opened; and the open end of the reaction chamber 1 is sealed with a cavity cover 6; the middle position of the cavity cover 6 is provided with a matching window 7 Windows;

A susceptor 3 is provided in the reaction chamber 1; the top of the susceptor 3 is fixedly connected to the bias electrode 4, the bias electrode 4 is directly opposite to the nozzle, and the top surface of the bias electrode 4 is adsorbed with a wafer 5;

The opening of the upper part of the coupling window 7 is insulated with an insulator between the pull element 14 and the middle coil. The entire upper radio frequency shield is shielded by the shielding box 18. At the same time, the radio frequency access block 22 for the radio frequency access of the pull element 14 and the lifting mechanism are opened. They are also respectively fixed in the shielding box 18, one end of the lifting mechanism is fixed to the top of the shielding box 18, and the other end is fixed to the radio frequency access block 22. The lifting mechanism includes a cylinder, a cylinder adapter plate 20, and a cylinder adapter insulating rod 21. The material of the cylinder adapter plate 20 is preferably 316L stainless steel. The material of the cylinder adapter insulating rod 21 is preferably ULTEM-1000, which provides the cylinder adapter plate 20 and The radio frequency access blocks 22 are insulated and supported while leaving enough space for the central ceramic air inlet. The material of the radio frequency access blocks 22 is preferably copper or aluminum, and the radio frequency access blocks 22 are connected to the radio frequency.

Another objective of the present invention is to provide a method based on a plasma processing system having a Raday element 14 with an opening method. Etch process, in which,

The specific steps of the wafer 5 etching process are:

1.1) Place the wafer 5 above the bias electrode 4 in the reaction chamber 1;

1.2) The cylinder goes up, and the radio frequency access block 22 is separated from the Faraday layer;

1.3) Rotate the knob 10 to open the Faraday layer to the second limit position; at this time, the first side profile 14-1a of each ring segment 14-1 constituting the Faraday layer can be tangent to the maximum open inscribed circle, The middle coil that is directly opposite to the maximum open inscribed circle is directly opposite to the coupling window 7;

1.4) Pass the process gas into the reaction chamber 1 through the ceramic gas inlet 16; pass the RF power supply that meets the demand into the middle coil;

1.5) Plasma etching is performed on the surface of wafer 5;

1.6) After the etching process is over, stop the process gas flow to the reaction chamber 1 and stop the power supply to the middle coil, and vacuumize the reaction chamber 1;

At the end of the etching process of the wafer 5, the Faraday layer is in an open state.

After the wafer 5 etching process, when the coupling window 7 cleaning process needs to be performed, the specific steps of the coupling window 7 cleaning process are as follows:

2.1) Place the substrate sheet above the bias electrode 4 in the reaction chamber 1;

2.2) The knob 10 is positioned by the rotary positioning surface 8 on the coupling window 7, and rotates clockwise around the O axis. The guide chute 11 on the knob 10 drives the second pin 13 of the ring segment 14-1 to rotate, and the second pin 13 The ring segment 14-1 is controlled to rotate around the first pin 12, and the first pin 12 rotates in cooperation with the pin hole 15 on the coupling window 7, and finally the Faraday layer is in a closed state. At this time, the inner portion of each ring segment 14-1 The arc surface 14-1b is located on the circumference of the concentric circle a outside the O axis, and the outer arc surface 14-1d of each ring segment 14-1 is located on the circumference of the concentric circle b outside the O axis;

2.3) The cylinder goes down, the radio frequency access block 22 is driven down by the cylinder adapter plate 20 and the cylinder adapter insulating rod 21, and finally the radio frequency access block 22 is pressed against each ring sector 14-1, and the radio frequency can be The access block 22 presses each ring segment 14-1 of the Faraday layer in the closed state close to the part of the inner circular arc surface 14-1b, so that the radio frequency access block 22 is conductively connected to each ring segment 14-1;

2.4) Purge the cleaning gas into the reaction chamber 1 through the ceramic gas inlet 16;

2.5) The Faraday layer is connected to the Faraday layer through the radio frequency access block 22 to meet the demand of radio frequency power;

2.6) After cleaning for a period of time, when there is a gap between two adjacent ring sectors 14-1, it is necessary to push the Faraday layer to rotate. The slits between the ring segments 14-1, and then maintain this state to continue cleaning for a period of time. Through this step, the coupling window 7 can be cleaned well; on the contrary, when two adjacent ring segments 14- There is no gap between 1 and completely covers the area where the coupling window 7 is in contact with the plasma, so there is no need to push the Faraday layer to rotate.

2.7) After the cleaning is completed, stop supplying cleaning gas to the reaction chamber 1 and stop supplying power to the Faraday layer, and vacuumize the reaction chamber 1.

When the cleaning process is over, the cylinder moves up, and the radio frequency access block 22 is driven up by the cylinder adapter plate 20 and the cylinder adapter insulating rod 21. The radio frequency access block 22 is separated from each ring segment 14-1, and the knob 10 passes through The positioning of the rotary positioning surface 8 on the coupling window 7 rotates counterclockwise around the O axis, the guide chute 11 on the knob 10 drives the second pin 13 of the ring segment 14-1 to rotate, and the second pin 13 controls the ring segment 14 -1 rotates around the first pin 12, the first pin 12 rotates with the pin hole 15 of the coupling window 7, and finally realizes that the Faraday layer is in an open state without any shielding of the middle coil, that is, the middle coil is completely exposed to the coupling window 7, The etching process can be started.

The opening method of the present invention can fully cover the Raday element 14 or partially cover the area where the coupling window 7 is in contact with the plasma, ensuring full coverage of cleaning. By controlling the opening and closing of the Faraday layer to cooperate with the etching and cleaning processes, it is achieved The chamber, especially the coupling window 7, is thoroughly cleaned. At the same time, when the opening and pulling layer is in the open state, there is no shielding of the excitation radio frequency coil, that is, the existence of the opening and pulling layer will not have any influence on the excitation of the coil. It will weaken the electric field strength of the coil coupling, so that it will not have any influence on the etching process. The foregoing descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

1: Reaction chamber 2: Support arm 3: Pedestal 4: Bias electrode 5: Wafer 6: Cavity cover 7: Coupling window 7-1: The central fixing hole of the coupling window 8: Rotate positioning surface 9: intake nozzle 10: Knob 11: Guide chute 12: The first pin 13: second pin 14: Open the legal Raday element 14-1: Ring fan 14-1a: The first side profile of the ring sector 14-1b: Inner arc surface of ring segment 14-1c: The second side profile of the ring sector 14-1d: The outer arc surface of the ring segment 15: pin hole 16: ceramic air inlet 17: Three-dimensional coil 18: shielding box 19: Cylinder 20: Cylinder adapter plate 21: Cylinder transfer insulating rod 22: RF access block 23: switch box 24: Power distribution box

Figure 1 shows a plasma processing system with a Raday element opening method. Figure 2 is a schematic diagram of the structure of the coupling window in Figure 1. Fig. 3 is a schematic diagram of a structure when the opening and closing of the Raday element in Fig. 1 is in a closed state. Fig. 4 is a schematic diagram of the structure of the opening of the Raday element in Fig. 3 when it is in an open state. Figure 5 is a schematic diagram of the structure of the fan-shaped piece in Figure 3. Fig. 6 is a flow chart of the method of the present invention based on the plasma processing system with the open-ended Raday element.

1: Reaction chamber

2: Support arm

3: Pedestal

4: Bias electrode

5: Wafer

6: Cavity cover

7: Coupling window

8: Rotate positioning surface

9: intake nozzle

10: Knob

13: second pin

14: Open the legal Raday element

16: ceramic air inlet

17: Three-dimensional coil

18: shielding box

19: Cylinder

20: Cylinder adapter plate

21: Cylinder transfer insulating rod

22: RF access block

23: switch box

24: Power distribution box

Claims (12)

An open-leg pull element, including a Faraday layer, the Faraday layer includes a knob, a radio frequency access block, a lifting mechanism that drives the radio frequency access block to move, and a plurality of ring segments that are evenly distributed on the outer side of the O axis and arranged in separate bodies ;in: The knob is in an annular shape as a whole, and is rotatably arranged concentrically on the outer side of the O axis, and is equidistantly provided along the annular surface of the knob with a number of guide chutes matching the number of ring segments; Each ring segment includes an inner circular arc surface, an outer circular arc surface, and a first side profile and a second side profile that connect the same sides of the inner circular arc surface and the outer circular arc surface respectively; at the same time, each ring The fan pieces are each provided with two positioning members on the fan surface close to the outer arc surface; the two positioning members are respectively a first positioning member and a second positioning member; Each ring segment is driven by the knob to rotate synchronously around the first positioning member provided on the respective fan surface, and the rotation range is limited by the guiding connection between the second positioning member and the guide chute on the knob Between the first extreme position and the second extreme position; When each of the ring segments is in the first limit position, the Faraday layer is in a closed state, the inner arc surface of each ring segment is on the circumference of the concentric circle a outside the O axis and is arranged equidistantly, and each of the The outer arc surfaces of the ring segments are located on the circumference of the concentric circle b outside the O axis and are arranged equidistantly, and the inner diameter of the concentric circle a is smaller than the inner diameter of the concentric circle b; When each ring segment is in the second limit position, the Faraday layer is in an open state, the first side profile of each ring segment can be tangent to the maximum opening inscribed circle, and the inner side of the knob is inscribed with the maximum opening The area corresponding to the circle is completely exposed; The radio frequency access block is connected to the power output end of the lifting mechanism; and Driven by the power of the lifting mechanism, the radio frequency access block can move toward the Faraday layer to electrically connect with the inner arc surface of each ring segment of the Faraday layer in the closed state, or move away from the Faraday layer , To separate from the Faraday layer in the open state. According to the opening method of claim 1, wherein the guide chute is a strip-shaped groove. According to claim 2, the opening method of the Raday element, wherein the strip-shaped groove is inclined. The opening method of the Raday element according to claim 1, wherein the first side profile and the second side profile are both straight profiles; or the first profile surface is a convex arc profile, and The second side profile is a concave arc profile. The opening and pulling element of claim 1, wherein the lifting mechanism includes a cylinder, a cylinder adapter plate, and a cylinder adapter insulating rod; the power output end of the cylinder is sequentially insulated through the cylinder adapter plate and the cylinder The rod is fixed with the radio frequency access block. According to the opening method of claim 1, wherein the first positioning member and the second positioning member are both pins. A plasma processing system with an opening method pull element, including a coupling window, the coupling window is provided with the opening method pull element as described in claim 1; A positioning member is positioned and connected with the coupling window; the coupling window is provided with a rotating positioning surface at a position corresponding to the outer edge of the knob; the knob can be rotated around the O axis through the positioning of the rotating positioning surface. According to claim 7, the plasma processing system with the opening method Raday element, wherein the opening method Raday element is provided with a coil structure, including a middle coil; the middle coil is orthographically projected on the inner area of the knob, and the The outer diameter of the middle coil is not greater than the diameter of the largest open inscribed circle; when each ring segment is in the first limit position, the inner arc surface of each ring segment in the closed state passes through the radio frequency access block and The Faraday radio frequency power supply is connected; when each of the ring segments is at the second limit position, the middle coil is completely exposed on the surface of the coupling window; the middle coil and the edge coil are both connected with the coil radio frequency power supply. According to claim 8, the plasma processing system with the open-leg Raday element, wherein the coil structure further includes an edge coil independently provided with respect to the middle coil; the edge coil can be orthographically projected on the inner area of the knob; When each ring segment is at the second limit position, the middle coil and the edge coil are completely exposed on the surface of the coupling window; the middle coil and the edge coil are both connected to the coil's radio frequency power supply. According to claim 7, the plasma processing system having the opening method and the pull element, wherein the first positioning member is a first pin; the coupling window is uniformly located at a position corresponding to the first pin on each ring segment A pin hole is provided; each ring segment is connected in a one-to-one correspondence with each of the pin holes on the coupling window through the first pin provided on the respective fan surface; the middle portion of the coupling window is provided with a middle fixing hole; the middle portion The fixed hole is equipped with a ceramic air inlet nozzle, and the air outlet part of the ceramic air inlet nozzle is equipped with a nozzle. According to claim 7, the plasma processing system with the open Raday element further includes a reaction chamber; the upper end of the reaction chamber is opened; and the open end of the reaction chamber is sealed with a cavity cover; A window matching the coupling window is arranged in the middle of the cavity cover; a base is arranged in the reaction chamber; Wafers are adsorbed on the surface; a shielding box is fixed on the top of the reaction chamber, the cross-section of the shielding box is U-shaped, and the shielding box and the cavity cover are hermetically connected; the radio frequency access block and the lifting mechanism are both set in the In the shielding box; one end of the lifting mechanism is fixed with the top of the shielding box, and the other end of the lifting mechanism is fixed with the radio frequency access block. A method based on a plasma processing system with a Raday element having an opening method includes two processes, namely a coupling window cleaning process and a wafer etching process, in which: The specific steps of the wafer etching process are: 1.1) Put the wafer above the bias electrode in the reaction chamber; 1.2) The cylinder goes up, and the radio frequency access block is separated from the Faraday layer; 1.3) Rotate the knob to open the Faraday layer to the second limit position; The first side profile of each ring segment constituting the Faraday layer can be tangent to the maximum open inscribed circle, and the middle coil directly opposite to the maximum open inscribed circle directly faces the coupling window; 1.4) Pass the process gas into the reaction chamber through the ceramic gas inlet nozzle; Connect the central coil with a radio frequency power supply that meets the demand; 1.5) Plasma etching on the surface of the wafer; 1.6) When the etching process is finished, stop the process gas flow into the reaction chamber and stop the power supply to the middle coil, and vacuumize the reaction chamber; The specific steps of the coupling window cleaning process are: 2.1) Place the substrate sheet above the bias electrode in the reaction chamber; 2.2) Turn the knob to make the Faraday layer in the closed state. At this time, the inner arc surface of each ring segment is on the circumference of the concentric circle a outside the O axis, and the outer arc surface of each ring segment is outside the O axis On the circumference of the concentric circle b; 2.3) When the cylinder goes down, press the RF access block to the position where each ring segment of the Faraday layer in the closed state is close to the inner arc surface, so that the RF access block is conductively connected to each ring segment; 2.4) Pour cleaning gas into the reaction chamber through the ceramic gas inlet nozzle; 2.5) Access to the Faraday layer with RF power that meets the requirements through the RF access block; 2.6) After the cleaning is completed, stop supplying cleaning gas to the reaction chamber and stop supplying power to the Faraday layer, and vacuumize the reaction chamber.

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