JP2003332314A - Electrode for plasma treatment equipment and plasma treatment equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode for plasma treatment equipment and plasma treatment equipment, capable of reducing the running cost and the manufacturing cost of a semiconductor device or the like, as compared to those of conventional ones. <P>SOLUTION: An upper electrode 20 is configured so that the overall shape is almost disc-shaped and comprises an internal member 200 (first member), provided with a plurality of gas discharge holes 21 and an external member 201 (second member), annularly configured so as to surround the periphery of the internal member 200, so that it is possible to replace only the internal member 200, when it is worn out due to plasma treatment. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for a plasma processing apparatus and a plasma processing apparatus for generating plasma and utilizing the plasma to perform etching processing, film forming processing and the like on a substrate to be processed such as a semiconductor wafer. Regarding

[0002]

2. Description of the Related Art Conventionally, a plasma processing apparatus has been widely used in which plasma is generated and the plasma is applied to an object to be processed to perform a predetermined process.

For example, in the field of manufacturing semiconductor devices, when a fine circuit structure of a semiconductor device is formed, plasma is applied to a substrate to be processed such as a semiconductor wafer to perform an etching process or a film forming process. There is.

Such plasma processing apparatus is divided into several types according to the difference in the means for generating plasma. Among them, in the so-called parallel plate type plasma processing apparatus, they are opposed to each other in the vacuum chamber. The upper electrode and the lower electrode are arranged in such a manner that high frequency power of a predetermined frequency is applied between the upper electrode and the lower electrode so that the predetermined processing gas introduced into the vacuum chamber is turned into plasma. Has become.

In this case, the substrate to be processed such as a semiconductor wafer is often configured to be placed on the lower electrode, and the upper electrode is filled with the above-mentioned predetermined processing gas. In many cases, a so-called shower head structure is provided in which a plurality of gas discharge holes are provided so that the gas can be uniformly supplied toward a semiconductor wafer or the like placed on the.

Further, since the upper electrode is exposed to plasma during the plasma treatment, sputtering or the like due to plasma may occur, and the sputtered particles may adhere to the semiconductor wafer or the like.

For this reason, there is also one in which the upper electrode is made of single crystal silicon, and it is considered that undesired impurities such as metal do not adhere to the semiconductor wafer or the like.

[0008]

However, in the above-mentioned upper electrode (electrode for plasma processing apparatus) of the shower head structure, in order to uniformly supply the processing gas to the entire surface of the semiconductor wafer to be processed, It is necessary to provide the gas discharge hole in a region having substantially the same diameter as the semiconductor wafer to be processed. Further, a region for providing a screw or the like for fixing the upper electrode is required around the upper electrode.

Therefore, the diameter of the entire upper electrode is larger than that of the semiconductor wafer to be processed. For example, the diameter of the upper electrode for processing a semiconductor wafer having a diameter of 8 inches is about 10 inches, that is, 12 inches. The diameter of the upper electrode for processing the semiconductor wafer is about 14 inches.

Further, as described above, when the upper electrode is made of single crystal silicon, single crystal silicon having a diameter of 14 inches is required to make the diameter of the upper electrode 14 inches.

Therefore, there is a problem that the manufacturing cost of the upper electrode becomes high. Furthermore, as described above, the upper electrode is consumed by being exposed to plasma, and, for example, in the case of an etching apparatus, it is 700 to 800 in the application time of high frequency power.
It is necessary to replace the upper electrode in a relatively short cycle such as time. Therefore, there is a problem that the running cost of the plasma processing apparatus increases, and as a result, the manufacturing cost of products such as semiconductor devices increases.

The present invention has been made in response to such a conventional situation, and is for a plasma processing apparatus capable of reducing the running cost and the manufacturing cost of a semiconductor device or the like as compared with the conventional case. It is intended to provide an electrode and a plasma processing apparatus.

[0013]

That is, the invention according to claim 1 is arranged in a vacuum chamber for accommodating a substrate to be processed and performing plasma processing, and high-frequency power is applied between the electrode and a counter electrode. An electrode for a plasma processing apparatus, which has at least a plurality of gas discharge holes for supplying a predetermined processing gas toward the substrate to be processed, and which forms a surface facing the substrate to be processed. And a second member disposed around the first member or in contact with the surface of the first member opposite to the facing surface, are detachably integrated to form a plasma treatment. It is characterized in that only the first member can be replaced when it is consumed by carrying out.

According to a second aspect of the invention, in the electrode for the plasma processing apparatus according to the first aspect, the outer diameter of the first member is substantially the same as that of the substrate to be processed, and the second member is It is characterized in that the second member is arranged so as to surround the periphery of the first member in a ring-shaped and integrated state.

According to a third aspect of the present invention, in the electrode for the plasma processing apparatus according to the first aspect, the first member and the second member are provided.
Is configured in a disk shape having substantially the same diameter and is integrated, the second member is disposed on the upper side and the first member is disposed on the lower side. .

According to a fourth aspect of the present invention, in the electrode for the plasma processing apparatus according to the third aspect, the first member and the second member are provided.
A plurality of the gas discharge holes are provided so as to penetrate the member.

According to a fifth aspect of the present invention, in the plasma processing apparatus electrode according to any one of the first to fourth aspects, the first
And the second member are made of silicon.

According to a sixth aspect of the invention, in the plasma processing apparatus electrode according to the fifth aspect, at least the first member is made of a silicon single crystal.

The invention according to claim 7 is the electrode for plasma processing apparatus according to claim 5 or 6, characterized in that the second member is made of polysilicon.

According to an eighth aspect of the present invention, in the plasma processing apparatus electrode according to any one of the first to seventh aspects, the temperature adjusting mechanism is in contact with the surface opposite to the surface facing the substrate to be processed. Is provided with a cooling plate.

According to a ninth aspect of the present invention, there is provided a plasma processing apparatus including an upper electrode composed of the electrode for plasma processing apparatus according to any one of the first to eighth aspects, and a lower electrode arranged so as to face the upper electrode. Is provided.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to an etching apparatus electrode and an etching apparatus will be described below with reference to the drawings.

FIG. 1 schematically shows the overall construction of the etching apparatus according to the present embodiment. In FIG. 1, reference numeral 1 is made of a material such as aluminum,
It shows a cylindrical vacuum chamber configured to be capable of hermetically closing the inside.

A mounting table 2 which also serves as a lower electrode is provided in the vacuum chamber 1, and the mounting table 2 is supported from the bottom of the vacuum chamber 1 via an insulating plate 3 made of ceramic or the like. .

An electrostatic chuck 4 is provided on the upper surface of the mounting table 2, that is, the mounting surface of the semiconductor wafer W. The electrostatic chuck 4 is configured by disposing an electrostatic chuck electrode 4b in an insulating film 4a, and a DC power supply 5 is connected to the electrostatic chuck electrode 4b. A focus ring 6 made of a conductive material or an insulating material is provided on the outer periphery above the mounting table 2.

A feed line 7 for supplying high-frequency power is connected to the mounting table 2 substantially in the center thereof. A matching box 8 and a high-frequency power source 9 are connected to the power supply line 7, and the high-frequency power source 9 supplies high-frequency power having a predetermined frequency, for example, in the range of several hundred KHz to one hundred and several tens MHz to the mounting table 2. It is like this.

Further, on the outside of the focus ring 6,
An exhaust ring 10 having an annular shape and having a large number of exhaust holes is provided, and through this exhaust ring 10,
The exhaust system 12 connected to the exhaust port 11 is configured to perform vacuum exhaust of the processing space in the vacuum chamber 1.

Further, in the mounting table 2, a flow path 13 for circulating a temperature control medium, and a temperature control gas such as helium between the mounting table 2 (electrostatic chuck 4) and the back surface of the semiconductor wafer W are provided. A gas flow path 14 for supplying the
With these mechanisms, the temperature of the semiconductor wafer W placed on the mounting table 2 can be adjusted to a predetermined temperature.

On the other hand, on the ceiling wall portion of the vacuum chamber 1 above the mounting table 2, the upper electrode 20 constituting the shower head is formed.
Are provided so as to face the mounting table 2 in parallel, and the upper electrode 20 and the mounting table (lower electrode) 2 function as a pair of electrodes.

The upper electrode 20 is provided with a large number of gas discharge holes 21 on its lower surface. In addition, the upper electrode 20
A gas diffusion space 22 is formed on the upper side of the gas diffusion space 22. A gas supply pipe 23 is provided at the ceiling of the gas diffusion space 22.
Are connected. A processing gas supply system 24 that supplies a processing gas for etching (etching gas) is connected to the other end of the gas supply pipe 23. The processing gas supply system 24 is a mass flow controller (MFC) 2
4a and the processing gas supply source 24b.

A matching box 25 and a high frequency power source 26 are connected to the upper electrode 20, and the high frequency power source 2
From 6, a predetermined frequency, for example, several hundred KHz to one hundred tens of M
High frequency power in the range of Hz is supplied.

On the other hand, around the outside of the vacuum chamber 1, an annular magnetic field forming mechanism (ring magnet) 27 is arranged concentrically with the vacuum chamber 1, and the mounting table 2 and the upper electrode 20 are arranged.
A magnetic field is formed in the processing space between and.
The magnetic field forming mechanism 27 is entirely rotatable by a rotating mechanism 28 around the vacuum chamber 1 at a predetermined rotation speed.

Next, an etching procedure by the etching apparatus configured as described above will be described.

First, the opening / closing mechanism (not shown) provided in the vacuum chamber 1 is opened, and the semiconductor wafer W is loaded into the vacuum chamber 1 by a transport mechanism (not shown) and placed on the mounting table 2. Then, a predetermined voltage is applied from the DC power supply 5 to the electrostatic chuck electrode 4b of the electrostatic chuck 4, and the semiconductor wafer W is attracted by the Coulomb force or the like.

After that, the transfer mechanism is evacuated to the outside of the vacuum chamber 1, the opening / closing mechanism is closed, and the inside of the vacuum chamber 1 is exhausted through the exhaust port 11 by the vacuum pump of the exhaust system 12. After the inside of the vacuum chamber 1 reaches a predetermined degree of vacuum, a predetermined etching gas is introduced into the inside of the vacuum chamber 1 from the processing gas supply system 24 at a predetermined flow rate, and the inside of the vacuum chamber 1 reaches a predetermined pressure, for example, 1.33 to 133 Pa (10
˜1000 mTorr).

In this state, the high frequency power supplies 9 and 26 supply high frequency power of a predetermined frequency (for example, several hundred KHz to hundreds of tens of MHz) to the mounting table 2 and the upper electrode 20.

In this case, a high frequency electric field is formed in the processing space between the mounting table 2 which is the lower electrode and the upper electrode 20, and a magnetic field is formed by the magnetic field forming mechanism 27.
In this state, plasma etching is performed.

When the predetermined etching process is performed, the high frequency power from the high frequency power sources 9 and 26 is stopped to stop the etching process, and the semiconductor wafer is reversely processed by the reverse procedure. W is carried out of the vacuum chamber 1.

FIG. 2 shows the structure of the above-mentioned upper electrode 20 in this embodiment in more detail. The upper electrode 20 is configured such that the entire shape thereof is a substantially disc shape, is provided with a large number of gas discharge holes 21, and is configured to serve as a semiconductor wafer W mounted on the mounting table (lower electrode) 2. An inner member 200 (first member) that constitutes the facing surface, and an outer member 2 that is annularly configured to surround the periphery of the inner member 200.
01 (second member).

The inner member 200 is formed of a silicon single crystal into a substantially disc shape, and its outer diameter is substantially the same as the diameter of the semiconductor wafer W to be processed. That is,
When the diameter of the semiconductor wafer W to be processed is 8 inches, the outer diameter of the inner member 200 is also about 8 inches, and when the diameter of the semiconductor wafer W to be processed is 12 inches, the outer diameter of the inner member 200 is also about 12 inches. It is said to be in inches. Also, the inner member 200
A step portion having a shape in which the upper side projects in the outer peripheral direction is formed on the outer peripheral edge portion of the outer member 20.
1 engages with a step formed on the inner peripheral portion of the inner member 20 and
0 and the outer member 201 are integrally locked.

Further, the outer member 201 is made of silicon single crystal in this embodiment, but the outer member 2
01 is not limited to silicon single crystal, and can be made of other silicon such as polysilicon, and the manufacturing cost can be reduced by being made of polysilicon or the like. The outer diameter of the outer member 201 is equal to that of the inner member 2
The outer diameter is larger than the outer diameter of 00 by about 2 inches. Then, the outer member 201 is locked by a locking member so that it is fixed in the vacuum chamber 1 shown in FIG.

Further, a cooling plate 202 is provided above the inner member 200 and the outer member 201, and these three members are integrally locked by a screw or the like not shown. This cooling plate 202
Is for reinforcing the inner member 200 and the outer member 201 and for cooling them. For this reason,
The material is made of metal, for example, aluminum whose surface is alumite treated, and has a temperature adjusting mechanism (not shown). This temperature adjusting mechanism is composed of, for example, a mechanism for circulating a temperature adjusting medium.

The cooling plate 202 is formed with through holes 21a corresponding to the gas discharge holes 21 formed in the inner member 201, but these through holes 21a are formed.
The diameter of is larger than the diameter of the gas discharge hole 21 in consideration of processing convenience and the like.

In the upper electrode 20 constructed as described above, the portion exposed to the plasma is scraped and consumed by repeating the plasma treatment. Such consumption is
Although it occurs at each part of the upper electrode 20 exposed to plasma, in particular, as shown in FIG. 3, the end portion of the gas discharge hole 21 on the side facing the semiconductor wafer W (indicated by symbol E in the figure).
Is conspicuous in the portion of the gas discharge hole 21, and the diameter of the end portion E of the gas discharge hole 21 is consumed so as to expand.

As shown in FIG. 3, the gas discharge hole 21 has a so-called trumpet shape, and when the diameter of the end portion E of the gas discharge hole 21 gradually increases, the aspect ratio of the gas discharge hole 21 is increased. Since (the ratio of the diameter to the length (depth)) changes, the plasma enters the inside of the gas discharge hole 21, the plasma acts on the cooling plate 202, and the alumite or the like forming the surface of the cooling plate 202 is removed. This causes a problem that particles are generated.

For this reason, for example, it is necessary to use the upper electrode 20 for a certain period of time, such as 700 to 800 hours for applying the high frequency power, and replace the upper electrode 20 when the upper electrode 20 is consumed. In the embodiment, such a case can be dealt with by exchanging only the inner member 200.

Therefore, in this embodiment, the inner member 2
00 and the outer member 201 are integrally configured without being divided, and the running cost can be significantly reduced as compared with the case where the entire integrated component is replaced.
The manufacturing cost of a silicon single crystal varies greatly depending on its diameter. For example, a silicon single crystal with a diameter of 14 inches is twice or more as large as a silicon single crystal with a diameter of 12 inches.

Next, another embodiment will be described with reference to FIG. In the embodiment shown in FIG. 4, the upper electrode 20
a is a lower member 200a (first member) and an upper member 2
01a (second member) and cooling plate 202
It is composed by. The lower member 200a and the upper member 201a are each made of single crystal silicon and have a thickness of 5 mm. When the lower member 200a and the upper member 201a are integrated, the total thickness is 10 mm. Is configured to be.

In the upper electrode 20a having the above-mentioned structure, the plasma treatment is repeatedly performed, so that the portion exposed to the plasma is cut away, and as shown in FIG. 5, the lower member 200a is removed.
The end portion E of the gas discharge hole 21 on the side is consumed so that the diameter thereof gradually increases. Therefore, as shown in FIG. 5, when the wear reaches the upper end of the lower member 200a, only the lower member 200a is replaced.

Therefore, in this embodiment, the lower member 2
00a and the upper member 201a are integrally formed without dividing them, and the running cost can be significantly reduced as compared with the case where the entire integrated component is replaced.

In the above embodiment, the lower member 200
a and the upper member 201a each have a thickness of 5 mm, and the total thickness is 10 mm, because the conventional electrode has a thickness of 10 mm and the end portion E of the gas discharge hole 21 is consumed. This is because the electrodes were exchanged when was about half (5 mm). Therefore, the thickness of each of the lower member 200a and the upper member 201a, and the total thickness thereof are not limited to the above, but can be changed as appropriate.

In the above embodiment, the present invention is
The example applied to the etching device of the type that supplies high frequency power to both the upper electrode and the lower electrode has been described.
The present invention is not limited to such a case, and can be applied to any plasma processing apparatus such as an etching apparatus of a type that supplies high-frequency power only to a lower electrode or a plasma processing apparatus that performs film formation.

[0053]

As described above, according to the electrode for the plasma processing apparatus and the plasma processing apparatus of the present invention, the running cost can be reduced as compared with the conventional one, and the manufacturing cost of the semiconductor device or the like can be reduced. You can

[Brief description of drawings]

FIG. 1 is a diagram showing an overall schematic configuration of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an upper electrode according to an embodiment of the present invention.

FIG. 3 is an enlarged view showing a main part of the upper electrode of FIG.

FIG. 4 is a diagram showing a schematic configuration of an upper electrode according to another embodiment of the present invention.

5 is an enlarged view showing a main part of the upper electrode of FIG.

[Explanation of symbols]

W: semiconductor wafer, 2: mounting table (lower electrode), 20
... upper electrode, 21 ... gas discharge hole, 200 ... inner member (first member), 201 ... outer member (second member), 202 ... cooling plate.

Claims (9)

[Claims] 1. An electrode for a plasma processing apparatus, which is disposed in a vacuum chamber for accommodating a substrate to be processed and performing plasma processing, and to which high-frequency power is applied between the electrode and a counter electrode, the electrode being at least the plasma processing device. A first member having a plurality of gas discharge holes for supplying a predetermined processing gas toward the processing substrate and forming a surface facing the substrate to be processed; and a periphery of the first member or the first member. A second member disposed in contact with the surface opposite to the facing surface of the member, is detachably integrated with the second member, and only the first member when consumed by performing plasma processing An electrode for a plasma processing apparatus, wherein the electrodes can be replaced. 2. The electrode for a plasma processing apparatus according to claim 1, wherein the first member has an outer diameter substantially equal to that of the substrate to be processed, and the second member has an annular shape. The electrode for a plasma processing apparatus, wherein in the integrated state, the second member is arranged so as to surround the periphery of the first member. 3. The electrode for a plasma processing apparatus according to claim 1, wherein the first member and the second member are formed in a disk shape having substantially the same diameter, and in the integrated state, An electrode for a plasma processing apparatus, wherein a second member is arranged on the upper side and the first member is arranged on the lower side. 4. The plasma processing apparatus electrode according to claim 3, wherein a plurality of the gas discharge holes are provided so as to penetrate the first member and the second member. Electrodes for processing equipment. 5. The plasma processing apparatus electrode according to claim 1, wherein the first member and the second member are made of silicon. Electrodes. 6. The electrode for plasma processing apparatus according to claim 5, wherein at least the first member is made of silicon single crystal. 7. The electrode for a plasma processing apparatus according to claim 5, wherein the second member is made of polysilicon. 8. The electrode for a plasma processing apparatus according to claim 1, wherein a cooling plate having a temperature adjusting mechanism is in contact with a surface opposite to a surface facing the substrate to be processed. An electrode for a plasma processing apparatus, which is provided. 9. A plasma comprising: an upper electrode composed of the electrode for a plasma processing apparatus according to claim 1, and a lower electrode arranged so as to face the upper electrode. Processing equipment.