TWI469213B - Plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to a plasma processing apparatus for plasma-treating a processing gas by high-frequency power, and applying a plasma or the like to the object to be processed.

In the manufacturing process of a flat panel such as a semiconductor device or a liquid crystal display device, in order to apply a process such as an etching process or a film formation process to a substrate to be processed such as a semiconductor wafer or a glass substrate, a plasma etching device or a plasma is used. A plasma processing apparatus such as a CVD film forming apparatus.

The plasma processing apparatus shown in Fig. 8 is an example of a configuration of a plasma etching apparatus that applies an etching treatment to a film formed on a glass substrate for an FPD (Flat Panel Display). This plasma etching apparatus is configured as a parallel plate type plasma processing apparatus, and a gas shower head upper electrode 12 which also serves as a gas supply unit is provided in a processing container 10 which is grounded, for example, made of aluminum or the like. The lower electrode 11 which also serves as a mounting table for the substrate S is provided so as to face the upper electrode 12. The upper electrode 12 is connected to the processing container 10 as an anode electrode, and the lower electrode 11 is fully electrically floated with respect to the processing container 10 by the insulating material 14, and becomes an integrated circuit (matching circuit) (not shown). It is connected to the cathode electrode of the high frequency power source 15. Further, as shown in Fig. 8, the peripheral portion and the side surface of the surface of the lower electrode 11 are shielded by an insulator such as ceramic for uniformly forming a plasma above the lower electrode 11. 18 is covered.

Fig. 9 is a view showing an equivalent circuit of a high-frequency current guiding circuit in the plasma etching apparatus. When the processing gas is supplied into the processing chamber 10, high-frequency power is applied between the upper electrode 12 and the lower electrode 11 by the high-frequency power source 15, and the processing gas is plasma-treated, because the lower electrode 11 and the upper electrode 12 are During the formation of the capacitive coupling C1, the high-frequency current from the high-frequency power source 15 flows through the lower electrode 11 → the plasma → the upper electrode 12 → the wall portion of the processing container 10 → the grounding path, and the plasma processing gas is utilized. Etching is performed on the substrate S placed on the lower electrode 11. Further, in detail, the high-frequency current is returned from the wall portion of the processing container 10 to the ground of the high-frequency power source 15 via the frame (matching box) of the matching circuit (not shown).

However, for example, the substrate S for FPD which is a target of the apparatus tends to be gradually enlarged, and accordingly, the processing container 10 is also increased in size. When the processing container 10 is enlarged, the impedance component of the processing container 10 becomes large, and the impedance of the path of the high-frequency current also increases. Therefore, the wall portion of the processing container 10, which is closer to the cathode than the anode electrode, looks like an anode from the cathode electrode, and the two members are easily capacitively coupled. Then, the current path of the impedance adjusting mechanism between the anode electrode and the processing container is known, and it is known that the impedance is relatively reduced (Patent Document 1). However, when the lower electrode 11 is a cathode electrode as in the above-described plasma etching apparatus, the side surface of the processing container 10 around the lower electrode 11 or the bottom surface and the lower electrode 11 are still in a state of being easily capacitively coupled.

Here, an exhaust passage 16 for exhausting the gas after the processing substrate S is disposed on the bottom surface of the processing container 10, and an exhaust port of the exhaust passage 16 is provided to prevent foreign matter from falling and entering the exhaust passage 16 Inside, and use The mesh member 17 for protection against plasma intrusion or generation in the exhaust passage 16 is suppressed. The mesh member 17 uses a metal material from the viewpoint of workability or strength. Then, in order to form a uniform plasma, it is preferable to have the same potential around it when viewed from the lower electrode 11, and it can be said that the mesh member 17 is in contact with the processing container 10 in accordance with the premise design, and becomes the same potential as the processing container 10. .

Therefore, the mesh member 17 disposed at a position close to the lower electrode 11 at the bottom of the processing container 10 becomes an anode electrode closer to the upper electrode 12 when viewed from the lower electrode 11, and is formed between the lower electrode 11 and the mesh member 17. The capacitance is combined (indicated by C2 in Fig. 9), for example, a glow discharge is easily generated. Then, the inventors of the present invention confirmed that the pressure in the processing vessel 11 is in the range of 0.67 Pa to 27 Pa (5 mtorr to 200 mtorr), and the processing gas is a halogen-based gas such as chlorine gas or CF ₄ gas. A negative gas represented by O ₂ gas or the like, that is, a molecule constituting the gas adheres to electrons to generate a large amount of negative ions, and the negative ions generate a gas having a larger amount of electrons than the electrons. Further, one side of the substrate S exceeds 1 m. A large substrate, and as described above, the mounting table is provided with the lower electrode 11.

Further, in the vicinity of the discharge port of the exhaust passage 16 through which the gas in the processing container 10 flows, the process conditions such as gas flow rate or pressure become various pressure environments, but generally the minimum voltage required for generating plasma between the electrodes is required. Since it is a function of the pressure in the space formed between the electrodes, it is combined with the above factors. The glow discharge is easily caused between the lower electrode 11 belonging to the cathode electrode and especially between the mesh member 17.

In this way, when an unnecessary capacitive coupling is formed between the lower electrode 11 and the mesh member 17, and a strong glow discharge is locally generated, there is a portion of the lower electrode 11 and the upper electrode 12 which belong to the original plasma generating space. The inter-plasma becomes unstable, causing an arc-like abnormal discharge on the surface of the member or the substrate S in the processing container 10, for example, causing a so-called arcing action, causing damage or loss to the members or the substrate S, Furthermore, the in-plane uniformity of the substrate S treatment is deteriorated due to the generation of uneven plasma.

[Patent Document 1] Japanese Patent Laid-Open No. 2005-340760; paragraph 0027, first figure

The present invention has been made in view of such circumstances, and an object thereof is to provide a plasma processing apparatus belonging to a parallel flat type, which can suppress plasma of abnormal discharge generated between a cathode electrode and a mesh member covering an exhaust port. Processing device.

In the plasma processing apparatus according to the present invention, high-frequency electric power is applied between the anode electrode and the cathode electrode which are disposed to face each other in the processing container, and the processing gas is plasma-treated to perform plasma treatment on the object to be processed. A plasma processing apparatus comprising: an exhaust port disposed on an outer side of the cathode electrode for discharging The processing gas; the conductive member covering the exhaust port; and an opening for allowing a processing gas discharged to the exhaust port to flow; and a dielectric body interposed between the conductive member and the inner wall of the processing container The impedance of the path of the cathode electrode passing through the conductive member to the processing container is increased.

Further, the conductive member is, for example, a metal, and the dielectric member is preferably a ceramic, and the conductive member preferably has a mesh shape.

Further, even if the first conductive member provided in the peripheral portion of the exhaust port and the upper side space covering the first conductive member and the first conductive member are provided, the first conductive member is provided to cover the exhaust port. The second conductive member provided in a spaced apart manner may be configured to have the conductive member as the second conductive member. Even in this case, the first conductive member and the second conductive member are made of a metal, and the dielectric material is preferably ceramic. When the first conductive member and the second conductive member have a mesh shape, or when the first conductive member has a mesh shape, and the second conductive member has a flat shape, it is preferable. Further, the second dielectric body may be provided between the first conductive member and the conductive wall portion of the processing container.

In the above-described plasma processing apparatus, it is preferable that the cathode electrode and the exhaust port are provided in a lower portion of the processing container, and the plasma processing device is a square substrate having an area of 4.0 m ² or more of the object to be processed, and is processed. The gas is a negative gas, and the pressure environment to be performed by the above plasma treatment is preferably 0.67 Pa or more, and preferably in the range of 27 Pa or less.

According to the present invention, in the parallel plate type plasma processing apparatus, a dielectric body is provided between the mesh member provided to the exhaust port of the processing container and the conductive wall portion of the processing container. As a result, the impedance of the so-called abnormal path from the cathode electrode having the mounting table to the processing container through the mesh member becomes large, and it is difficult for the cathode electrode and the mesh member to be capacitively coupled, and abnormal discharge can be suppressed. Therefore, the generation of the arc can be suppressed, and the damage of the member or the substrate in the processing container can be suppressed.

Hereinafter, an embodiment of the etching processing apparatus 2 to which the plasma processing apparatus of the present invention is applied to an FPD substrate will be described with reference to Figs. 1 to 4 . The etching processing apparatus 2 is provided inside the processing container 20 having a vacuum chamber for applying an etching treatment to the substrate S of the object to be processed, for example, an FPD substrate, and the processing container 20 is formed into a quadrangular shape, for example, in a planar shape, and The processing container 20 is grounded via a frame 64 of a matching case, which will be described later.

The substrate S is an angular glass substrate having a length of more than 1 m, and the processing container 20 is configured such that the shape of the substrate S is, for example, 3.5 m on one side of the horizontal cross section and 3.0 m or so on the other side. For example, it is composed of a good conductive material having thermal conductivity such as aluminum. On one side wall 21 of the processing container 20, a loading/unloading port 22 for carrying the substrate S into the processing container 20 is formed, and the loading and unloading port 22 is provided by a gate valve 23 forms a switch freely.

Inside the processing container 20, a mounting table 3 for placing the substrate S thereon is disposed. The first high-frequency power supply unit 311 for generating the plasma in the stage 3 and the second high-frequency power supply unit 312 for ion introduction in the plasma are electrically connected to each other via the matching circuits 62 and 63, and the processing container 20 is electrically connected. The plasma is generated to function as a cathode electrode for introducing ions in the plasma to the surface of the substrate S. Further, the matching circuits 62 and 63 are housed in a conductive frame 64 belonging to the matching box, and the frame 64 is connected to the bottom wall of the processing container 20 via the conductive line member 65. Since the frame 64 is connected to the ground side of the first and second high-frequency power supply units 311 and 312, the processing container 20 is grounded via the frame 64.

The mounting table 3 is placed on the bottom surface of the processing container 20 via the dielectric member 32, whereby the mounting table 3 belonging to the lower electrode is electrically floated from the processing container 20. Further, the peripheral region and the side surface of the surface of the mounting table 3 are covered by a shadow ring 33 made of a ceramic material for uniformly forming plasma on the mounting table 3.

Further, the mounting table 3 is provided with a transfer device (not shown) outside the etching processing device 2, and a lift pin 34 for performing transfer of the substrate S between the mounting table 3. The lift pins 34 are configured to be expandable and contractible from the surface of the mounting table 3 by the elevating mechanism 35, to be able to perform the transfer of the substrate S between the external transport means, and to be placed on the surface of the mounting table 3 at the position where the substrate S is placed. The substrate S is raised and lowered.

Further, a flat plate belonging to the anode electrode is provided above the mounting table 3 inside the processing container 20 so as to face the surface of the mounting table 3. The upper electrode 4 is supported by the gusset-shaped upper electrode base 41. The upper electrode 4 and the upper electrode base 41 are made of, for example, aluminum. Furthermore, the upper surface of the upper electrode base 41 is fixed to the patio portion of the processing container 20 via the dielectric body 45, and the upper electrode 4 and the base 41 thereof are electrically connected to the processing via the impedance adjusting mechanism 6 and the conductive cover 61. Container 20.

The impedance adjusting mechanism 6 functions to adjust the impedance from the upper electrode 4 to the processing container 20, and uses a capacitor-containing circuit such as a variable capacitor to make the capacitance of the plasma (C1) by the capacitance component (C) of the impedance adjusting mechanism 6. And the impedance (L) of the path from the upper electrode 4 to the lower portion of the processing container 20 is offset. Accordingly, the impedance adjusting mechanism 6 sets the impedance of the path of the mounting table 3 (lower electrode) → the plasma → the upper electrode 4 → the impedance adjusting mechanism 6 → the processing container 20 → the ground to j (-1/ω c1 + ω L - 1/ω C) plays a role in reducing the impedance of the abnormal path described later.

Further, a space surrounded by the upper electrode base 41 and the upper electrode 4 constitutes a gas diffusion space 42 for etching gas. Hereinafter, the upper electrode 4, the upper electrode base 41, and the like are wound around the gas shower head 40. Further, the processing portion of the processing container 20 is connected to the gas diffusion space 42, and a processing gas supply path 43 is provided. The other end side of the processing gas supply path 43 is connected to be used to etch the gas through the gas diffusion space 42. It is supplied to the processing gas supply unit 44 in the processing container 20.

Here, as shown in Fig. 1 and Fig. 2, a space between the side surface of the mounting table 3 and the side wall portion 21 is provided, for example, of a member made of an aluminum member having a surface treated with an oxygen barium aluminum. A flat plate 25 of the shape. Separate The plate 25 is disposed in a region on the outer side of the four sides of the mounting table 3, and is disposed in the space formed by the plasma between the mounting table 3 and the gas shower head 40. The position before 241. The separator 25 serves to restrict the flow of the etching gas supplied to the surface of the substrate S on the mounting table 3 to the exhaust port 241, thereby suppressing the flow deviation of the gas and uniformly flowing the etching gas on the entire surface of the substrate S. As shown in Fig. 2, at the four corners on the outer side of the partition plate 25, the flow port 251 in which the partition plate 25 is provided is opened, and the etching gas supplied into the processing container 20 flows into the downstream side through the partition plate 25. .

As shown in Figs. 1 to 3, an opening portion constituting the horizontally long exhaust port 241 is formed in the bottom wall of the processing container 20. An exhaust pipe constituting the exhaust passage 24 is connected below the exhaust port, and the flow end of the exhaust pipe is expanded into a shape corresponding to the horizontally long exhaust port 241 by the expansion portion 242, and is The flange portion forming the opening edge of the flared portion 242 is hermetically bonded to the lower surface side of the bottom wall of the processing container 20. The exhaust port 241 is, for example, a bottom wall of the processing container 20 between the mounting table 3 and the side wall portion 21, and is disposed along each of the side wall portions 21 so as to have a total of eight places at two places, and the pressure is constituted by, for example, a butterfly valve or the like. The adjustment mechanism 26 is disposed as an exhaust pipe on the flow side below the respective exhaust ports 241. Then, the exhaust pipe is joined to the vacuum pump 27 at the downstream end after the flow side merges under the pressure regulating mechanism 26.

Each of the exhaust ports 241 is covered by a mesh member 51 made of a metal such as aluminum, which is a conductive member, as shown in Fig. 3 and Fig. 4(a), as described in the prior art. The mesh member 51 functions to suppress the foreign matter from falling, intruding into the exhaust passage 24, and the plasma invades into the exhaust passage. The role of 24. In this example, the mesh of the mesh member 51 corresponds to the opening of the conductive member.

The mesh member 51 is a small-sized dielectric body 52 made of, for example, ceramics such as alumina, as shown in FIG. 3 and FIG. 4(b), and a bolt 511 formed of a dielectric body made of ceramic. And the like, and is connected to the bottom wall surface of the processing container 20, and is fixed from the bottom wall surface by, for example, a gap of 5 mm to 20 mm. The dielectric member 52 is, for example, at eight locations around the exhaust port 241, and partially supports the mesh member 51 in a state in which the dielectric member 52 is present between the metal processing container 20 and the mesh member 51.

As shown in FIG. 1, the etching processing apparatus 2 is connected to the control unit 7. The control unit 7 is constituted by a computer including, for example, a CPU (not shown) and a storage unit, and a program for programming a group of commands (commands) for control or the like is recorded in the storage unit, and the control is related to the etching processing device 2 The operation is carried out by carrying the substrate S into the processing container 20 and applying the etching treatment to the substrate S placed on the mounting table 3 until the loading is performed. The program is stored in a memory medium such as a hard disk, a CD, a magneto-optical disk, a memory card, etc., and is installed on the computer since then.

Hereinafter, the operation of the etching processing apparatus 2 according to the present embodiment will be described. First, when the user of the operation unit (not shown) selects the program processing method of the target etching process for the control unit 7, the control unit 7 outputs a control signal to each unit of the etching processing device 2 according to the process processing method. As a result, a specific etching process is performed on the substrate S.

Specifically, first, the gate valve 23 is opened, and the substrate S on which the A1 film is formed on the surface is carried into the processing container 20 by an external conveying means (not shown). It is conveyed to the delivery position of the upper side of the mounting area of the mounting part 3. Then, the lift pins 34 are raised, and the substrate S is picked up from the transport means by the lift pins 34 at the transfer position, and the lift pins 34 are lowered to mount the substrate S on the mounting area on the mounting table 3. During this period, the transport means for transferring the substrate S is withdrawn to the outside of the processing container 20, and the loading/unloading port 22 is closed by the gate valve 23.

Then, the processing gas supply unit 44 discharges a halogen-based negative gas such as chlorine gas for etching processing toward the substrate S, and adjusts the internal space of the processing container 20 to a specific pressure. Then, the first high-frequency power supply unit 311 for generating plasma, for example, applies 5.5 kW of high-frequency power of 13.56 MHz to the mounting table 3, and the second high-frequency power supply unit 312 for ion introduction from the plasma For example, a high-frequency power of 3.2 MHz is applied to the mounting table 3, and the plasma of the space formed on the upper side of the substrate S is subjected to etching treatment of the substrate S according to the main reaction shown by the following formula (1). .

3Cl ^* +Al→AlCl ₃ ...(1)

When the flow of the etching gas in the processing container 20 at this time is explained, the etching gas supplied from the gas shower head 40 is plasma-formed while being lowered between the upper and lower electrodes 4 and 3, and is reached to After the substrate S, the substrate S flows on the surface of the substrate S and the separator 25, and flows into the flow port 251. Then, the space below the partition 25 is exhausted to the exhaust passage 24 through the respective exhaust ports 241.

Further, by plasma-etching the etching gas, the high-frequency power flows through the mounting table (lower electrode) 3 → the plasma upper electrode 4 (gas shower head 40) → the impedance adjusting mechanism 6 → the processing container 20 → belongs to the matching The box frame 64 → a so-called normal path to which the first and second high-frequency power sources 311 and 312 are grounded. At this time, in the vicinity of the mounting table 3 belonging to the lower electrode, a mesh member 51 covering the exhaust port 241 of the exhaust passage 24 is provided, and the environment around the mesh member 51 is also exhausted as described in the prior art. The gas flows into the exhaust port 241, and various pressure environments are formed in accordance with the process processing method. Therefore, there is a pressure environment in which a glow discharge is likely to occur between the mesh member 51 and the mounting table 3, but the mesh member 51 that supports the electric conductor that can be viewed from the mounting table 3 in accordance with the dielectric member 52 is provided. In a state, a capacitance formed between the mesh member 51 and the processing container 20 via the dielectric body 52 is applied to a so-called abnormal path including the mounting table 3 including the shielding ring 33 → the plasma → the mesh member 51 → the processing capacitor 20 → the ground. The impedance of the abnormal path becomes large. As a result, the mesh member 51 can suppress the display of the anode electrode which is closest to the cathode electrode, and it is difficult to see the anode electrode, and the glow discharge is generated in the mounting table 3 and the mesh member 51, and the degree can be suppressed to a small extent even if a discharge is generated. .

According to the etching processing apparatus 2 according to this embodiment, the following effects are obtained. In the etching processing apparatus 2 of the plasma processing apparatus of the parallel flat type, the dielectric body 52 is provided between the mesh member 51 covering the exhaust port 241 of the processing container 20 and the conductive processing container 20. State. As a result, the impedance of the so-called abnormal path from the cathode electrode having the mounting table 3 through the mesh member 51 to the processing container 20 becomes large. The cathode electrode and the mesh member are difficult to be capacitively coupled, and abnormal discharge can be suppressed. Therefore, generation of arc can be suppressed, and damage or loss of members or substrates in the processing container 20 can be suppressed. Further, it is possible to suppress the plasma shift caused by the instability of the capacitive coupling between the upper electrodes 4, and to perform the substrate S processing with high in-plane uniformity.

Further, when to be described in detail for this effect, the substrate area of 1m ² or more, when a large substrate S 4m ² or more of the particular, since it is easy capacitive coupling between the cathode 20 and the processing vessel, or around the member, so that it is performed The impedance adjustment mechanism 6 is interposed between the anode electrode and the processing container 20. However, the vicinity of the exhaust port 241 of the processing container 20 is subjected to various pressure environments by the process processing method, and in particular, a glow discharge is easily generated in a pressure range of 0.67 Pa to 27 Pa (5 mtorr to 200 mtorr). When a halogen-like gas such as chlorine gas is used as the processing gas, since the degree of dissociation of the gas is large, glow discharge is more likely to occur, and in the etching processing apparatus 2 of such a complete condition, with respect to the processing container 20 The structure in which the mesh member 51 is electrically floated is extremely effective for performing processing in which the in-plane uniformity is high for a large substrate.

In addition, in the above-described embodiment, the plasma processing apparatus 2 of the type including the impedance adjusting mechanism 6 is exemplified, but the present invention is applicable to a plasma processing apparatus of a type having such an impedance adjusting mechanism 6 According to this, the impedance of the abnormal path previously described can be increased to suppress the occurrence of abnormal discharge. However, by providing the impedance adjusting mechanism 6, the impedance of the normal path can be easily reduced with respect to the impedance of the abnormal path, and the present invention can be obtained by disposing the dielectric 2 between the mesh member 51 and the processing container 20. The effectiveness of the effect.

Here, the configuration of the mesh member or the dielectric body is not limited to those illustrated in FIGS. 4(a) and 4(b). For example, as shown in FIGS. 5(a) and 5(b), a dielectric body 52a surrounding the entire periphery of the exhaust port 241 of the exhaust passage 24 is provided, even if the support has, for example, a suitable dielectric body. The mesh member 51a of the flange portion 512 having the shape of 52a may also be used. Since the gap between the bottom wall surface of the processing container 20 and the mesh member 51a is buried by the dielectric body 52a, foreign matter is prevented from falling through the gap and entering the exhaust path 24.

Further, as shown in Fig. 6, in a state where the metal mesh member 53 is brought into contact with the peripheral portion of the exhaust port 241, it is fixed by, for example, a metal screw, and covers the upper portion of the mesh member 53. The space is formed in a convex shape, and the second mesh member 51b provided to be spaced apart from the mesh member 53 is provided in a state in which the second mesh member 51b is fixed to the dielectric member 52. In this example, the second mesh member 51b corresponds to the second conductive member of the patent application, and the mesh member 53 corresponds to the first conductive member of the patent application. In this case, in the processing container 20 including the existing mesh member 53 that is provided in contact with the peripheral portion of the exhaust port 241, since the second mesh member 51b can be added, it is easy to be modified. The advantages of the device. Further, in this example, it is of course possible to make the second dielectric body interposed between the mesh member 53 and the processing container 20.

In addition, in the other example in which the first conductive member and the second conductive member are provided, for example, the separator 25 is used as the second conductive member, and the dielectric material is fixed on the side wall surface of the processing container 20. The composition of the board 25 can also . In this case, for example, the flow port 251 provided at the four corners around the mounting table 3 corresponds to the opening of the conductive member. However, even if the flow port 251 is not provided, the opening portion of the partition plate 25 may be provided, and even if In addition to the flow port 251, an opening may be provided in the main body of the partition plate 25.

Further, the cathode electrode of the present invention is not limited to the case where the plasma processing apparatus 2 as described above is provided on the mounting table. For example, even if the upper electrode 4 is connected to the high-frequency power supply unit for plasma generation, and a position where capacitive coupling can occur between the upper electrodes, for example, the side wall portion of the processing container is provided with the upper and lower frequency types of the exhaust port 241, The present invention can also be applied to a side vent type plasma processing apparatus.

Then, the cathode electrode to which the present invention can be applied is not limited to the mounting table 3 exemplified in the embodiment. For example, even if a sheet-like electrode embedded in a ceramic mounting table is used as a cathode, a high frequency plasma processing device is applied to only the upper electrode or a high frequency is applied to both the upper electrode and the lower electrode. In the plasma processing apparatus of the type, even the upper electrode can be used as the cathode electrode. In addition, the material for conductivity is not limited to a metal, and may be, for example, a conductive resin or a conductive ceramic.

Further, the plasma processing apparatus of the present invention is applied not only to the etching treatment of the aluminum film but also to the etching of the metal film or the insulating film of the aluminum alloy, titanium, titanium alloy or the like, the semiconductor film or the laminated film. Further, it is also applicable to plasma treatment or the like in which processing is performed on the object to be processed using other processing gases, such as ashing or CVD (Chemical Vapor Deposition) other than the etching treatment. Moreover, the object to be processed is not limited to a square substrate, even if the FPD base A semiconductor wafer or the like other than the board may be used.

[Examples]

[Example 1]

A model machine for producing the etching processing apparatus 2 shown in the embodiment is configured to apply high-frequency power to the mounting table 3 when the dielectric body 52 is disposed between the processing container 20 and the mesh member and when it is not disposed. At the time of the stage 3 - the state between the mesh components. The second mesh member 51b (made of aluminum, hereinafter simply referred to as "mesh member 51b") having a convex shape as shown in Fig. 6 is provided in the exhaust port 241 of the exhaust passage 24, and oxygen as a processing gas is supplied at 6000 sccm. . The pressure in the processing container 20 is set to 13 Pa (100 mtorr), 10 kW is applied from the first high-frequency power supply unit 311 at 13.56 MHz, and 10 kW is applied from the second high-frequency power supply unit 312 at 3.2 MHz.

A. Experimental conditions

(Example 1)

A dielectric body 52 made of aluminum is disposed between the mesh member 51b and the bottom wall surface of the processing container 20.

Comparative example 1

The mesh member 51b is directly fixed to the bottom wall surface of the processing container 20, and is electrically connected to the two members.

B. Experimental results

Fig. 7(a) shows the state between the mounting table 3 and the mesh member 51b in (Example 1), and the result of (Comparative Example 1) is shown in Fig. 7(b). According to Fig. 7(a), no significant light emission was observed in the vicinity of the mesh member 51b. In the experiment of (Example 1), it was found that the discharge of the mounting table 3 - mesh member 51b was suppressed. Further, when it is shown in Fig. 7(b), it is understood that the light having a high luminance is detected on the upper surface of the mesh member 51b, and in the experiment of (Comparative Example 1), a relatively strong glow is generated between the mounting table 3 and the mesh member 51b. Discharge. From the above experimental results, it was confirmed that when the dielectric member 52 is provided between the mesh member 51b and the processing container 20, the discharge between the mounting table 3 and the mesh member 51b can be suppressed as compared with the case where the dielectric member 52 is not provided.

(Example 2)

Under the same conditions as in (Experiment 1), a small piece of silicon wafer was placed on the mesh member 51b, high frequency power was applied to the mounting table 3 for 7 minutes, and when the dielectric body 52 was placed and the dielectric body 52 was not provided. The amount of digging in the small period of the period.

A. Experimental conditions

(Example 2)

A dielectric body 52 is disposed between the mesh member 51b and the processing container 20.

(Comparative Example 2)

The mesh member 51b is directly fixed to the bottom wall surface of the processing container 20, and is electrically connected to the two members.

B. Experimental results

According to the result of (Example 2) (Comparative Example), the amount of digging (741 Å) of the small piece in the dielectric body 52 (Example 2) was set, compared to the case where the dielectric body 52 (Comparative Example 2) was not provided. The amount of digging (1186 Å) is about 40% less. This is because the dielectric body 52 suppresses the occurrence of discharge between the mounting table 3 and the mesh member 51b, and it can be said that the damage and loss of the surrounding members can be reduced. Here, in the short time during which the experiments of (Example 2) and (Comparative Example 2) were performed, the arc in the etching processing apparatus 2 was not confirmed. However, as in the prior art, in the etching process of the actual substrate S, since the etching processing apparatus 2 is continuously operated for a long period of time, when the dielectric body 52 is not provided, during the period, the mounting stage 3 - the upper portion The capacitive coupling between the electrodes 4 is unstable, and the arc rate becomes high. When the arc is generated, it is expected that the damage and the loss of the generated portion are extraordinarily larger than the amount of the excavation shown in the above (Comparative Example 2), and even if no arc is generated, the image shown in Fig. 7(b) is generated. In the state of light emission, since the surface of the mesh member is consumed, the effect of providing the dielectric body 52 is large even for these points.

S‧‧‧FPD substrate (substrate)

2‧‧‧ etching treatment device

3‧‧‧ mounting table

4‧‧‧Upper electrode

7‧‧‧Control Department

20‧‧‧Processing container

21‧‧‧ Sidewall

22‧‧‧ Move in and out

23‧‧‧ gate valve

24‧‧‧Exhaust road

25‧‧‧Baffle

32‧‧‧Dielectric

34‧‧‧lifting pin

35‧‧‧ Lifting mechanism

40‧‧‧Sprinkler

41‧‧‧Upper electrode base

42‧‧‧ gas diffusion space

43‧‧‧Processing Gas Supply Department

44‧‧‧Process Gas Supply Department

51, 51a, 51b‧‧‧ mesh components

52, 52a‧‧‧ dielectric

53‧‧‧2nd mesh component

241‧‧‧Exhaust port

242‧‧‧Exhaust Road Connections

251‧‧‧ circulation

311‧‧‧1st high frequency power supply unit

312‧‧‧2nd high frequency power supply unit

511‧‧‧ screw

512‧‧‧Flange

Fig. 1 is a longitudinal sectional view showing the configuration of an etching treatment apparatus according to an embodiment of the present invention.

Fig. 2 is a plan view showing the structure inside the processing container of the etching processing apparatus.

Fig. 3 is an enlarged longitudinal sectional view showing the structure in the vicinity of the exhaust portion of the processing container.

Fig. 4 is a plan view of the mesh member and its supporting member provided in the processing container.

Fig. 5 is a plan view showing a modification of the mesh member and its supporting member.

Fig. 6 is an enlarged longitudinal sectional view showing a second modification of the mesh member.

Fig. 7 is an explanatory view showing the results of experiments conducted in the first embodiment.

Fig. 8 is a longitudinal sectional view showing the configuration of a conventional etching processing apparatus.

Fig. 9 is a circuit diagram showing an equivalent circuit of a conventional etching processing apparatus.

S‧‧‧FPD substrate (substrate)

2‧‧‧ etching treatment device

3‧‧‧ mounting table

4‧‧‧Upper electrode

6‧‧‧Impedance adjustment mechanism

7‧‧‧Control Department

20‧‧‧Processing container

21‧‧‧ Sidewall

22‧‧‧ Move in and out

23‧‧‧ gate valve

24‧‧‧Exhaust road

25‧‧‧Baffle

26‧‧‧ Pressure regulating mechanism

27‧‧‧Vacuum pump

32‧‧‧Dielectric

33‧‧‧ shadow ring

34‧‧‧lifting pin

35‧‧‧ Lifting mechanism

40‧‧‧Sprinkler

41‧‧‧Upper electrode base

42‧‧‧ gas diffusion space

43‧‧‧Processing Gas Supply Department

44‧‧‧Process Gas Supply Department

45‧‧‧Dielectric

51‧‧‧Net components

52‧‧‧ dielectric

61‧‧‧ Cover

62‧‧‧Matching circuit

63‧‧‧Matching circuit

64‧‧‧ frame

241‧‧‧Exhaust port

311‧‧‧1st high frequency power supply unit

312‧‧‧2nd high frequency power supply unit

Claims (12)

A plasma processing apparatus which applies high-frequency electric power between an anode electrode and a cathode electrode which are disposed to face each other in a processing container, plasma-processes a processing gas, and performs plasma processing on the object to be processed, and is characterized in that: a discharge port disposed on an outer side of the cathode electrode for discharging the processing gas; and a conductive member covering the exhaust port and having an opening for allowing a processing gas discharged to the exhaust port to flow; And a dielectric body is provided between the conductive member and the inner wall of the processing container, so that the impedance of the path of the cathode electrode to the processing container through the conductive member increases. The plasma processing apparatus according to claim 1, wherein the conductive member is a metal, and the dielectric body is a ceramic. The plasma processing apparatus according to claim 1, wherein the conductive member has a mesh shape. The plasma processing apparatus according to the first aspect of the invention, comprising: a first conductive member that covers the exhaust port, is provided at a peripheral portion of the exhaust port, and covers the first conductive member In the second conductive member provided in the upper side space and spaced apart from the first conductive member, the conductive member is a second conductive member. The plasma processing apparatus according to the fourth aspect of the invention, wherein the first conductive member and the second conductive member are metal, and the dielectric body is ceramic. The plasma processing apparatus according to the fourth aspect of the invention, wherein the first conductive member and the second conductive member have a mesh shape. The plasma processing apparatus according to the fourth aspect of the invention, wherein the first conductive member has a mesh shape, and the second conductive member has a flat shape. The plasma processing apparatus according to claim 4, further comprising a second dielectric provided between the first conductive member and the conductive wall portion of the processing container body. The plasma processing apparatus according to any one of claims 1 to 4, wherein the cathode electrode and the exhaust port are provided in a lower portion of the processing container. The plasma processing apparatus according to any one of claims 1 to 4, wherein the processed system has a square substrate having an area of 4.0 m ² or more. As described in any one of claims 1 to 4 of the patent application A plasma processing apparatus, wherein the gas is a negative gas. The plasma processing apparatus according to any one of claims 1 to 4, wherein the plasma treatment is formed in a pressure environment in a range of 0.67 Pa or more and 27 Pa or less.