JP2004039658A - Plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing apparatus which can reduce a damage occurrence capability of a cylindrical member as compared with a prior art, which can improve an apparatus operating factor by lowering a maintenance frequency and reduce a running cost, and which can improve productivity. <P>SOLUTION: A cylindrical member 40 is inserted from an inside of a shielding ring 19 into a locking through hole 30, and a locking flange 41 of a rear end is brought into contact with a planar contact surface 31 formed on a periphery of the through hole 30 of the inside of the ring 19. A bolt 50 is screwed from an outside of the ring 19 into the member 40. The ring 19 is supported to an insulator ring 15 by projecting a tip of this bolt 50 from the member 40 and bringing the tip of the bolt 50 into contact with the ring 15. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma processing apparatus that generates a plasma and performs an etching process, a film forming process, and the like on a target substrate such as a semiconductor wafer using the plasma.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a plasma processing apparatus that generates plasma and performs a predetermined process by causing the plasma to act on an object to be processed has been frequently used.
[0003]
For example, in the field of manufacturing semiconductor devices, when forming a fine circuit structure of a semiconductor device, plasma is applied to a substrate to be processed such as a semiconductor wafer to perform an etching process, a film forming process, and the like.
[0004]
Among such plasma processing apparatuses, for example, in a plasma processing apparatus for a semiconductor wafer, since the semiconductor wafer is formed in a substantially disc shape, a member formed in a disc shape or an annular shape is used. Often.
[0005]
For example, in a so-called parallel plate type plasma processing apparatus, an upper electrode and a lower electrode provided in a vacuum chamber so as to face each other are also usually formed in a disk shape in the case of a plasma processing apparatus which processes a semiconductor wafer. An annular member such as a so-called focus ring is provided around the lower electrode, and an annular member such as a so-called shield ring is provided around the upper electrode.
[0006]
In addition, in the case of the above-mentioned shield ring or the like, it is often formed of a material such as quartz in order to prevent undesired discharge from occurring or mixing into semiconductor wafers as undesired impurities.
[0007]
However, when such a shield ring or the like is made of quartz, it is difficult to directly form a screw on the quartz shield ring or the like to support it. Therefore, only a through hole for locking is formed in the shield ring or the like. A cylindrical member (bushing) which is formed in a cylindrical shape with a resin or the like and has a screw formed inside is disposed in the through hole for stopping, and a bolt similarly formed of a resin or the like is screwed into the cylindrical member. Supporting a shield ring or the like on a support member is performed.
[0008]
The above-mentioned cylindrical member is provided with a locking flange on the rear end side, and the locking flange is in contact with a contact surface around the locking through-hole to rotate the cylindrical member. And so on.
[0009]
[Problems to be solved by the invention]
However, the present inventors have conducted a detailed investigation and found that, in the conventional plasma processing apparatus having the above-described configuration, the above-described cylindrical member was damaged, in particular, a boundary portion between the cylindrical portion of the cylindrical member and the locking flange portion. The cylindrical member is likely to be damaged in a short period of time, and the cylindrical member is damaged in a short period of time. Therefore, frequent maintenance is required and the cylindrical member must be replaced. It has been found that costs may increase and productivity may be reduced.
[0010]
The present invention has been made in view of such a conventional situation, and it is possible to reduce the possibility of occurrence of breakage of a cylindrical member as compared with the related art, to reduce the maintenance frequency, to improve the apparatus operation rate, and to reduce the running cost. It is an object of the present invention to provide a plasma processing apparatus capable of reducing the amount of light and improving the productivity.
[0011]
[Means for Solving the Problems]
That is, the plasma processing apparatus according to the first aspect of the present invention includes a vacuum chamber for accommodating a substrate to be processed, generating plasma, and performing plasma processing on the substrate to be processed, and a locking chamber formed along a radial direction. An annular member having a hole, disposed in the vacuum chamber, a support member supporting the annular member, and a cylindrical member having a screw formed therein and inserted into the locking through hole. A cylindrical member having a rear end formed with a locking flange abutting on a contact surface around the locking through hole; and a cylindrical member inside the cylindrical member from a side opposite to the locking flange. And a bolt that locks the annular member to the support member by contacting the distal end portion with the locking member. The contact surface with the flange for use is formed in a flat shape. That.
[0012]
A second aspect of the present invention is the plasma processing apparatus according to the first aspect, wherein the annular member is made of quartz.
[0013]
According to a third aspect of the present invention, in the plasma processing apparatus according to the first or second aspect, the cylindrical member and the bolt are made of resin.
[0014]
According to a fourth aspect of the present invention, in the plasma processing apparatus according to the third aspect, a hexagonal hole for a hexagonal wrench is formed in the head of the bolt so as to be located at each apex of the hexagon. It is characterized in that a hexagonal hole formed by drilling and cutting each of these small holes is provided.
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is applied to an etching apparatus will be described below with reference to the drawings.
[0016]
FIG. 1 schematically shows the overall schematic configuration of an etching apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes a material made of, for example, aluminum or the like so that the inside can be hermetically closed. 3 shows a cylindrical vacuum chamber.
[0017]
In the vacuum chamber 1, there is provided a substrate mounting table 2 which is formed in a substantially disk shape and also serves as a lower electrode. The substrate mounting table 2 is connected to the vacuum chamber 1 via an insulating plate 3 made of ceramic or the like. It is supported from the bottom.
[0018]
An electrostatic chuck (not shown) is provided on the surface of the substrate mounting table 2. In the substrate mounting table 2, for example, a temperature control medium flow for circulating a cooling insulating fluid as a temperature control medium is provided. A gas flow path 5 for supplying a temperature control gas such as helium is formed between the passage 4 and the mounting surface and the back surface of the semiconductor wafer W, and is arranged on the substrate mounting table 2 by these mechanisms. The temperature of the semiconductor wafer W thus adjusted can be adjusted to a predetermined temperature.
[0019]
Further, a focus ring 6 formed of a conductive material or an insulating material in an annular shape is provided so as to surround the periphery of the mounting surface of the substrate mounting table 2 on which the semiconductor wafer W is mounted.
[0020]
A power supply line 7 for supplying high-frequency power is connected to a substantial center of the substrate mounting table 2. A matching box 8 and a high-frequency power supply 9 are connected to the power supply line 7, and a high-frequency power of a predetermined frequency, for example, a range of several MHz to one hundred and several tens MHz is supplied from the high-frequency power supply 9 to the substrate mounting table 2. It has become so.
[0021]
Further, on the outside of the focus ring 6, there is provided an exhaust ring 10 having an annular shape and formed with a large number of exhaust holes, and an exhaust system 12 connected to an exhaust port 11 via the exhaust ring 10. Thereby, the processing space in the vacuum chamber 1 is evacuated.
[0022]
On the other hand, an upper electrode 13 constituting a shower head is provided on the top wall portion of the vacuum chamber 1 above the substrate mounting table 2 so as to face in parallel with the substrate mounting table 2. The mounting table (lower electrode) 2 functions as a pair of electrodes.
[0023]
The upper electrode 13 is provided with a number of gas discharge holes 14 on its lower surface. The periphery of the upper electrode 13 is supported by an insulator ring 15 made of an insulating material, for example, Al ₂ O ₃ or the like, and a gas diffusion space 16 is formed above the upper electrode 13. Have been. A gas supply pipe 17 is connected to the ceiling of the gas diffusion space 16, and a processing gas supply system 18 that supplies a processing gas for etching (etching gas) is connected to the other end of the gas supply pipe 17. Have been. The processing gas supply system 18 includes a mass flow controller (MFC) (not shown) and a processing gas supply source.
[0024]
Outside the insulator ring 15, a shield ring 19 is formed in a ring shape from quartz or the like so as to cover the lower surface of the insulator ring 15 and the lower surface of the peripheral portion of the upper electrode 13. The configuration of the portion where the shield ring 19 is attached to the insulator ring 15 will be described later.
[0025]
On the other hand, an annular magnetic field forming mechanism (ring magnet) 20 is arranged around the outside of the vacuum chamber 1 concentrically with the vacuum chamber 1, and is disposed in a processing space between the substrate mounting table 2 and the upper electrode 13. A magnetic field is formed. The entire magnetic field forming mechanism 20 is rotatable around the vacuum chamber 1 at a predetermined rotation speed by a rotation mechanism 21.
[0026]
Next, the configuration of the above-described shield ring 19 attached to the insulator ring 15 will be described.
[0027]
As shown in FIG. 2, a plurality of (four in the example shown in FIG. 2) locking through holes 30 (indicated by dotted lines in the figure) are formed in the shield ring 19 along the radial direction thereof. They are arranged at intervals (in the example shown in FIG. 2, intervals of 90 degrees).
[0028]
These locking through-holes 30 are provided with cylindrical members 40 configured as shown in FIGS. The cylindrical member 40 is formed in a cylindrical shape from a resin, for example, PEA, and has a screw formed on an inner surface thereof, and a rectangular locking flange 41 is provided at a rear end thereof.
[0029]
As shown in FIG. 5, the cylindrical member 40 is inserted into the locking through-hole 30 from the inside of the shield ring 19, and the locking flange 41 at the rear end is used to lock the inside of the shield ring 19. It is configured to be in contact with a planar contact surface 31 formed around the use through hole 30. The contact surface 31 is formed by cutting a rectangular area around the locking through hole 30 from above the shield ring 19 into a flat shape according to the shape of the locking flange 41. is there.
[0030]
By forming the contact surface 31, the locking flange 41 comes into surface contact with the contact surface 31 over substantially the entire surface.
[0031]
For this reason, this planar contact surface 31 is not formed, and the planar locking flange 41 contacts the inner surface of the arcuate shield ring 19 in a line contact state or a point contact state, as compared with the case where the planar engagement flange 41 contacts the inner surface of the arcuate shield ring 19. As a result, the force applied to the locking flange 41 can be dispersed, and the concentration of stress can be prevented from being partially concentrated. For example, the cylindrical portion of the cylindrical member 40 and the locking flange portion can be prevented from being concentrated. It is possible to greatly reduce the possibility of breakage at a boundary portion or the like.
[0032]
As a result, the maintenance cycle relating to replacement of the cylindrical member 40 and the like can be lengthened, so that the operation rate of the apparatus can be improved as compared with the related art, and the running cost can be reduced. Thus, productivity can be improved.
[0033]
As shown in FIG. 5, a bolt 50 is screwed into the cylindrical member 40 from outside the shield ring 19, and the tip of the bolt 50 projects from the cylindrical member 40 and abuts on the insulator ring 15. By doing so, the shield ring 19 is configured to be supported by the insulator ring 15. The bolts 50 are screwed into the four cylindrical members 40 inserted into the four locking through holes 30, respectively. The mounting position of the shield ring 19 with respect to the insulator ring 15 can be adjusted.
[0034]
The bolt 50 is made of resin, for example, Vespel (registered trademark, manufactured by DuPont), and has a hexagonal hole 51 for a hexagonal wrench formed in the head of the bolt 50 as shown in FIGS. Have been. The hexagonal hole 51 is formed by first drilling small holes 52 at the apexes of the hexagonal holes 51 on the head of the bolt 50 with a drill or the like, and using an end mill or the like to form a hexagonal hole between the small holes 52. It is formed by cutting into a shape.
[0035]
In addition, when forming a hexagon hole for a hexagon wrench on a bolt made of a normal metal, the hexagon hole is formed by electric discharge machining, but in the case of a resin bolt like the bolt 50, the hexagon hole is formed by electric discharge machining. Can not. For this reason, conventionally, a bolt having a minus groove formed by cutting has been used. However, when the minus groove is locked by a minus driver and the bolt is rotated, this is one of the causes of slipperiness and lowering the maintainability. . On the other hand, by using the bolt 50 having the hexagonal hole 51 formed by the above-described method, it is possible to greatly improve the maintainability as compared with the related art.
[0036]
Next, an etching procedure using the etching apparatus configured as described above will be described.
[0037]
First, an opening / closing mechanism (not shown) provided in the vacuum chamber 1 is opened, and the semiconductor wafer W is carried into the vacuum chamber 1 by a transfer mechanism (not shown) and placed on the substrate mounting table 2. Then, the semiconductor wafer W is attracted by Coulomb force or the like by an electrostatic chuck (not shown).
[0038]
Thereafter, after the transport mechanism is retracted out of the vacuum chamber 1, the opening / closing mechanism is closed, and the inside of the vacuum chamber 1 is evacuated through the exhaust port 11 by the vacuum pump of the exhaust system 12. After the inside of the vacuum chamber 1 has a predetermined degree of vacuum, a predetermined etching gas is introduced into the vacuum chamber 1 from the processing gas supply system 18 at a predetermined flow rate, and the inside of the vacuum chamber 1 has a predetermined pressure, for example. The pressure is maintained at 1.33 to 133 Pa (10 to 1000 mTorr).
[0039]
Then, in this state, high frequency power of a predetermined frequency (for example, several MHz to one hundred and several tens MHz) is supplied from the high frequency power supply 9 to the substrate mounting table 2.
[0040]
In this case, a high-frequency electric field is formed in the processing space between the substrate mounting table 2 as the lower electrode and the upper electrode 13, and a magnetic field is formed by the magnetic field forming mechanism 20, and in this state, the semiconductor wafer W Is performed.
[0041]
During this etching process, a cooling insulating fluid is circulated in the temperature control medium flow path 4 of the substrate mounting table 2, and the mounting surface of the substrate mounting table 2 and the semiconductor wafer are passed through the gas flow path 5. The semiconductor wafer W is maintained at a predetermined temperature by supplying a temperature control gas such as helium between the back surface of W and the W.
[0042]
When the predetermined etching process is performed, the supply of the high-frequency power from the high-frequency power supply 9 is stopped to stop the etching process, and the semiconductor wafer W is removed from the vacuum chamber 1 in a procedure reverse to the procedure described above. Take it out.
[0043]
When the etching process of the semiconductor wafer W is performed according to the above-described procedure, the cylindrical member may be damaged before a normal maintenance cycle (the integrated time of the process is about 200 hours). In the embodiment, the cylindrical member 40 was able to be used in a good condition without being damaged before such a maintenance cycle.
[0044]
In the above-described embodiment, an example in which the present invention is applied to the support portion of the shield ring 19 has been described. However, the present invention is not limited to such a case, and the present invention is similarly applied to other annular members. Of course, you can do that. Further, not only the entire shape of the member is not limited to the annular shape, but also a configuration in which a part of the member is annularly formed and locked by the portion of the annularly formed member. Can be applied.
[0045]
Furthermore, in the above-described embodiment, an example in which the present invention is applied to an etching apparatus of a type that supplies high-frequency power to a lower electrode has been described. However, the present invention is not limited to such a case. The present invention can be applied to any plasma processing apparatus such as an etching apparatus of a type that supplies high-frequency power to both the lower electrode and the lower electrode, and a plasma processing apparatus that performs film formation.
[0046]
【The invention's effect】
As described above, according to the plasma processing apparatus of the present invention, it is possible to reduce the possibility of occurrence of breakage of the cylindrical member as compared with the related art, reduce the frequency of maintenance, improve the operation rate of the apparatus, and reduce the running cost. Can be performed, and productivity can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of an entire plasma processing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing an overall schematic configuration of a shield ring of the plasma processing apparatus of FIG. 1;
FIG. 3 is an enlarged view showing a schematic configuration of a cylindrical member of the plasma processing apparatus of FIG. 1;
FIG. 4 is an enlarged view showing a schematic side view of the cylindrical member of FIG. 3;
FIG. 5 is an enlarged view showing a schematic configuration of a main part of the plasma processing apparatus of FIG. 1;
FIG. 6 is an enlarged view showing a schematic configuration of a bolt of the plasma processing apparatus of FIG. 1;
FIG. 7 is an enlarged view showing a schematic cross-sectional configuration of the bolt of FIG. 6;
[Explanation of symbols]
W: Semiconductor wafer, 1: Vacuum chamber, 2: Substrate mounting table, 13: Upper electrode, 15: Insulator ring, 19: Shield ring, 30: Locking through hole, 31 ... Contact surface, 40: cylindrical member, 41: locking flange, 50: bolt.

Claims (4)

A vacuum chamber for accommodating the substrate to be processed and generating plasma, and performing plasma processing on the substrate to be processed;
An annular member having a locking through-hole formed along a radial direction and disposed in the vacuum chamber;
A support member on which the annular member is supported,
A cylindrical member having a screw formed therein and inserted into the locking through hole, and a locking flange formed at the rear end to be in contact with a contact surface around the locking through hole. Cylindrical member,
A bolt that is screwed into the cylindrical member from the side opposite to the locking flange, and that locks the annular member to the support member by abutting a distal end portion on the locking member. Plasma processing apparatus,
A plasma processing apparatus, wherein a contact surface of the annular member with the locking flange is formed in a planar shape. The plasma processing apparatus according to claim 1,
A plasma processing apparatus, wherein the annular member is made of quartz. The plasma processing apparatus according to claim 1 or 2,
The plasma processing apparatus, wherein the cylindrical member and the bolt are made of resin. The plasma processing apparatus according to claim 3,
In the head of the bolt, a hexagonal hole for a hexagonal wrench, a small hole is drilled so as to be located at each apex of the hexagon, and a hexagonal hole formed by cutting each of these small holes is formed. A plasma processing apparatus, which is provided.

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