JPH0945495A - Plasma processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intensify a substrate processing capacity per unit time without impairing vacuum sealing performance, and also without increasing the temperature of a charge tube. SOLUTION: A plasma assembling device which is one of plasma processing devices, is equipped with a vacuum processing chamber 10, a wave guide 30 transferring micro waves, and a discharge tube 20 which is penetrated through the wave guide 30, is connected to a gas feed port for generating plasma at its one end, and is inserted into the vacuum processing chamber 10 at the other end. In the vacuum processing chamber 10, a cylindrical wall 41 is mounted while the upper portion of a substrate 11 is closed in such a way that a gas flow can be guided to the top of the aforesaid substrate 11, and the unnecessary dispersion of gas is prevented by letting gas flow in the inside of the wall 41 with respect to the substrate 11. Therefore, let gas effectively act on the substrate 11, and a substrate processing capacity per unit time can thereby be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus having a large substrate processing capacity.

[0002]

2. Description of the Related Art Plasma CVD (Chemical Vapor Deposition) is used in the process of manufacturing LSIs for semiconductor products and other electronic components.
Although devices such as a device, a plasma etching device, and a plasma ashing device are widely used, since the above LSI and the like are mass-produced products, it is desired that the plasma processing device has a large substrate processing capability per unit time. ing.

Next, a plasma ashing device will be described as an example of the plasma processing device. FIG. 5 is a side sectional view of a conventional microwave plasma ashing apparatus.

In the figure, the plasma ashing apparatus 1 is roughly classified into a vacuum processing chamber 10 for accommodating a substrate 11 to be ashed, a discharge tube 20 to which oxygen gas required for ashing is supplied, and which is turned into plasma. Discharge tube 2
0, and a waveguide 30 having a microwave power source 31 for applying a microwave to the start end portion.

Protrusions 12a and 12b are provided on the inner wall of the vacuum processing chamber 10 so as to face each other.
Gas rectifier 1 supported by a and 12b and provided with many holes
3 are installed. A metal support 14 is provided below the gas rectifier 13, the substrate 11 is placed thereon, and a substrate heating heater 15 is provided below the substrate 11. Further, an insert fixing portion 16 for inserting and supporting the end portion of the discharge tube 20 is provided on the side wall of the vacuum processing chamber 10, and a vacuum valve 18 is provided at an exhaust port 17 provided on the bottom wall. A vacuum pump 19 is connected via.

On the other hand, the discharge tube 20 penetrates the waveguide 30 at a right angle with a gap provided, and one end (the right end in the figure) of the discharge tube 20 is fixed to the insertion fixing portion 16 of the vacuum processing chamber 10 as described above. O
Inserted and supported through a ring 21, a vacuum seal is provided between the two by the O-ring 21, and the other end (left end in the figure) of the discharge tube 20 is illustrated for introducing oxygen gas for plasma conversion. It is adapted to be inserted into and supported by a gas supply port portion which does not exist via an O-ring. The discharge tube 20
Is made of an insulating material such as quartz glass, sapphire, or alumina.

A microwave power source 31 is connected to a starting end portion (lower end portion in the figure) of the waveguide 30, and a stub tuner 32 is inserted below the discharge tube 20 by passing through the waveguide 30.
A terminal matching unit 33 is provided at the terminal end (upper end in the figure) of the waveguide 30 for matching the microwaves.

Next, the operation of the above-mentioned conventional plasma ashing apparatus will be described. The plasma ashing apparatus 1 uses plasma to neutralize neutral radicals (oxygen atoms).
Using the oxygen that has become, microfabrication of semiconductor integrated circuits,
For example, it is an apparatus for removing the resist film used for the etching process by ashing.

After the substrate 11 on which the resist film used for fine processing such as an electronic circuit remains, is placed on the support 14 in the vacuum processing chamber 10 of the plasma ashing apparatus 1 of FIG. 5, the vacuum valve 18 is opened. The vacuum pump 19 evacuates the vacuum processing chamber 10 and the discharge tube 20 connected thereto, and the heater 15 heats the substrate 11 to a predetermined temperature.

On the other hand, when a microwave having a frequency of 2.45 GHz is applied to the discharge tube 20 by the microwave power supply 31 while supplying oxygen gas into the discharge tube 20 from a cylinder (not shown) through the gas supply port, Discharge occurs in the discharge tube 20 and the oxygen gas is turned into plasma. After the discharge is generated, if necessary, the insertion depth of the stub tuner 32 is adjusted so that the reflected wave of the microwave becomes small.

Thereafter, the supplied oxygen gas is made into plasma by passing through the discharge plasma region 22, becomes a gas containing highly active neutral oxygen radicals, and is introduced into the vacuum processing chamber 10, where it is further introduced. The gas is rectified by the gas rectifier 13 and uniformly transported onto the substrate 11,
It reacts with the upper resist film and removes it. The removed material is discharged to the outside of the system by the vacuum pump 19.

[0012]

The conventional microwave plasma ashing apparatus having the above-mentioned structure is constructed and operates as described above, but it is to improve throughput (processing amount per unit time) of this apparatus. Is required. And to improve throughput, ashing speed,
That is, it is most effective to increase the resist film thickness to be ashed per unit time, but it is not easy to increase the microwave power input for that purpose.

That is, in the conventional plasma ashing apparatus, the ions existing in the generated plasma are generated by the substrate 11.
In order to prevent the characteristics of the electronic circuit or the like on the substrate 11 from being deteriorated by being irradiated on the discharge tube 2, the discharge tube 2 provided separately is not discharged in the vacuum processing chamber 10 where ashing is performed.
The discharge is performed within 0 to separate the plasma generation part and the ashing part. However, in this case, if the power of microwaves input to increase the ashing speed is increased, the temperature of the discharge tube 20 rises, and the vacuum sealability of the insertion fixing portion 16 by the O-ring 21 is impaired. there were.

The present invention solves the above-mentioned problems of the prior art and increases the substrate processing capacity per unit time in the plasma processing apparatus without impairing the vacuum sealability or raising the temperature of the discharge tube. Moreover, it is an object to prevent the substrate from being contaminated with impurities.

[0015]

In order to solve the above problems, the invention of claim 1 provides a vacuum processing chamber for accommodating a substrate to be plasma-processed, and a gas supply port for plasma generation at one end. In the plasma processing apparatus having the discharge tube inserted into the vacuum processing chamber at the other end, unnecessary diffusion of gas is performed on the substrate placed in the vacuum processing chamber while surrounding the substrate. The present invention is characterized in that a blocking wall is provided, and unnecessary diffusion is blocked by flowing the gas through the wall so that the gas is effectively used for the substrate.

The invention according to claim 2 is characterized in that the wall for preventing unnecessary diffusion of the gas is constituted by a cylindrical wall, and the invention according to claim 3 is characterized in that the wall is vacuum. It is characterized in that it is configured with a wall integrated with the wall of the processing chamber.

According to a fourth aspect of the present invention, a substrate is placed on a substrate electrode installed in a vacuum processing chamber, and is electrically connected above the substrate electrode and installed in parallel for gas permeation. It is characterized in that a wall for preventing unnecessary diffusion of gas is provided in a state surrounding the upper side of the counter electrode having the slit.

The inventions of claims 5 to 7 are:
The material of the wall provided above the substrate to prevent unnecessary diffusion of gas with respect to the substrate is a substance that does not cause impurity contamination of the substrate,
The wall is composed of aluminum or aluminum oxide (alumina), and the invention of claim 6 is composed of a metal having a non-metal film adhered to the surface thereof. The above-mentioned wall is made of quartz.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a side sectional view of a microwave plasma ashing apparatus 1A showing a first embodiment (embodiment) of the present invention, which is illustrated for comparison with a conventional example. The same reference numerals as those used above indicate the same or similar parts, and detailed description thereof will be omitted.

Referring to FIG. 1, a plasma ashing apparatus 1A according to the present invention includes a vacuum processing chamber 10 for accommodating a substrate 11 to be ashed, a discharge tube 20 for supplying oxygen gas used for ashing to generate plasma, Discharge tube 2
And a waveguide 30 having a microwave power source 31 at the start end for applying microwaves to the vacuum processing chamber 1.
0 is a metal support 1 for mounting the substrate 11 below the gas rectifier 13 supported by the protrusions 12a and 12b.
4 and a heater 15 for heating the substrate, and the discharge tube 20 is provided with an O-ring 21 at the end portion for vacuum sealing, which is no different from the conventional example (FIG. 5).

In the plasma ashing apparatus 1A of this embodiment, a wall 41 is installed below the gas rectifier 13 so as to surround the upper side of the substrate 11 so as to guide the gas flow in the vacuum processing chamber 10. This is different from the conventional example (FIG. 5).

In this embodiment, the gas flowing from the discharge tube 20 changes its flow downward by the rectifier 13 as shown by the arrow, and then flows along the space surrounded by the wall 41 up to the vicinity of the substrate 11. Most of the gas is exhausted after reaching the substrate 11. The wall 41 is the substrate 11
It is a cylindrical type that is concentrically formed with and is mounted directly below the rectifier 13. In determining the height of the wall 41, the unnecessary diffusion of gas is prevented and the substrate 11
It is necessary to set the distance from the substrate mounting table 14 so that the air can be sufficiently exhausted. However, if this gap is too large, the effect of introducing gas into the substrate 11 by the wall 41 is reduced.

Next, the operation will be described. Vacuum processing chamber 1
The vacuum valve 1 is mounted on the substrate mounting table 14 in the substrate 0 with the surface of the resist film to be removed facing up.
8 is opened and the vacuum processing chamber 10 is operated by the vacuum pump 19.
And the discharge tube 20 integrated with this is evacuated. Next, the heater 11 heats the substrate 11 to a predetermined temperature. When a microwave having a frequency of 2.45 GHz is applied to the discharge tube 20 by the microwave power supply 31 while supplying oxygen gas from a cylinder (not shown) into the discharge tube 20, discharge is started and the oxygen gas is turned into plasma. . After the discharge is generated, the insertion depth of the stub tuner 32 is adjusted so that the reflected wave of the microwave becomes small if necessary.

Thereafter, the supplied oxygen gas is converted into plasma by passing through the discharge plasma region 22, becomes a gas containing highly active neutral oxygen radicals, and is introduced into the vacuum processing chamber 10 to perform the vacuum processing. In the chamber 10, the gas rectified by the gas rectifier 13 flows along the wall 41 surrounding the upper side of the substrate 11 as shown by the arrow, reaches the substrate 11, and reacts with the resist film on the surface, Remove this.

As described above, the plasma ashing apparatus 1A of this embodiment differs from the conventional example (FIG. 5) in that the wall 41 is provided above the substrate 11 so as to surround the substrate 11. As a result, the ashing speed is improved in the ashing device 1A.

FIG. 4 shows the plasma ashing apparatus 1 according to the conventional example (FIG. 5) and the plasma ashing apparatus 1A according to the present embodiment (FIG. 1), in which a wall 41 is attached to the plasma ashing apparatus 1 so as to surround the substrate. In the present invention A, the resist film thickness to be ashed per unit time, that is, the ashing speed is shown on the horizontal axis under the same conditions except for the structure.
FIG. 6 is a comparative diagram comparing the example with the conventional example B. As shown in FIG. 4, in the apparatus 1A of the embodiment of the present invention, the ashing speed is about 1.4 times that of the apparatus 1 of the conventional example.

The material of the wall 41 is the substrate 11
Is a substance that does not cause impurity contamination, and aluminum or aluminum that has been subjected to a surface oxide film adhesion treatment (treatment for applying a coating by anodic oxidation or thermal spraying of alumina (Al ₂ O ₃ )), or quartz, or It has been confirmed as a result of an experiment that alumina (aluminum oxide) meets the condition and that the same effect of improving the processing speed was obtained in the above examples.

FIG. 2 is a side sectional view of a plasma ashing apparatus 1B showing a second embodiment (embodiment) of the present invention, in which the same reference numerals as those shown in FIG. 1 are the same or similar. It indicates a part.

In this embodiment, the wall 42 provided so as to surround the upper side of the substrate 11 is formed integrally with the wall of the vacuum processing chamber 10 (apparatus wall). In this respect, the first embodiment ( It differs from Figure 1).

Also in this embodiment, as in the first embodiment described above, the ashing speed can be greatly improved as compared with the conventional example (FIG. 5), and the wall and device provided so as to surround the substrate 11 are provided. By the wall 42 that is integrated with the wall,
Protrusions for mounting the gas rectifier 13 at both ends (12 in FIG. 1)
(a, 12b) and the cylindrical wall (same as 41) can also be used, and the structure is simple and easy to assemble.

FIG. 3 is a side sectional view of a plasma ashing apparatus 1C showing a third embodiment (embodiment) of the present invention. In the figure, the same symbols as those shown in FIG. 1 are the same or similar. It indicates a part.

In this embodiment, a substrate electrode 43 and a counter electrode 44 are provided above and parallel to the substrate electrode 43.
4 is electrically connected, and the counter electrode 44 is provided with a slit 44 a through which the gas rectified by the gas rectifier 13 in the vacuum processing chamber 10 passes. In the case of the ashing device having such a structure, the cylindrical wall 45 that blocks the unnecessary diffusion of gas is installed in the range extending from the gas rectifier 13 to the upper surface of the counter electrode 44, and the gas causes the slit 44 a of the counter electrode 44 to pass through. It passes through to reach the substrate 11. In the figure, 46 and 47 are substrate electrodes 4
3 is a matching box and an RF power source connected in series.

In this embodiment, when the surface of the resist film on the substrate 11 is hardened, first, both electrodes 4 are
The resist film cured by using the ions generated by the RF discharge by 3, 44 is removed, and the uncured layer (part) of the resist film is removed by radicals generated in the discharge tube 20. In this case, However, in a state of being surrounded above the counter electrode 44 which is electrically connected above the substrate electrode 43 and has slits for gas permeation that are installed in parallel,
By providing the wall 45 for preventing unnecessary diffusion of gas, the ashing speed can be significantly improved as compared with the conventional example, as in the first embodiment described above.

Although the respective embodiments (embodiments) of the present invention have been described above, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention. For example, with respect to the plasma processing apparatus of the present invention, ashing of a resist mask with oxygen gas turned into plasma has been illustrated in the present embodiment. However, Si, SiO ₂ , Si ₃ N _{4 and the} like obtained by turning CF ₄ into gas plasma are mainly used. It is also effective for removing the film as a component, that is, for etching. In other words, the plasma processing apparatus of the present invention also includes a plasma etching apparatus.

[0035]

As described above, according to the present invention,
In the invention of claim 1, a vacuum processing chamber for accommodating a substrate to be plasma-processed, and a discharge tube having one end serving as a gas supply port for plasma generation and the other end inserted into the vacuum processing chamber. In the plasma processing apparatus including the above, by providing a wall for preventing unnecessary diffusion of gas in a state surrounding the substrate with respect to the substrate placed in the vacuum processing chamber, the gas for the substrate in the vacuum processing chamber is provided. Since unnecessary diffusion of the gas is prevented and the gas effectively acts on the substrate, the substrate processing capacity per unit time can be improved.

According to the second aspect of the present invention, since the cylindrical wall is provided for the substrate placed in the vacuum processing chamber so as to surround the upper side of the substrate, the substrate processing capacity per unit time is increased. In addition, the wall for preventing unnecessary diffusion of gas to the substrate is usually constituted by a simple cylindrical wall having a circular shape, so that the structure is simple and the manufacture is easy.

Further, in the invention of claim 3, the wall for preventing unnecessary diffusion of the gas is constituted by a wall which is integrated with the wall of the vacuum processing chamber, so that the substrate processing capacity per unit time is increased. Not only is this improved, cost is reduced due to the reduced number of components, and assembly is easier.

Further, in the invention of claim 4, the substrate is placed on the substrate electrode installed in the vacuum processing chamber, and the gas transmission is electrically connected above the substrate electrode and set in parallel. In the plasma processing apparatus provided with the substrate electrode and the counter electrode having the gas permeation slit, by providing a wall for preventing unnecessary diffusion of gas in a state surrounding the counter electrode having the slit of As described above, the ashing speed can be significantly improved as compared with the conventional example by preventing unnecessary diffusion of the gas with respect to.

Further, in each of the fifth to seventh aspects of the invention, the wall provided so as to surround the upper side of the substrate is made of a substance that does not cause impurity contamination of the substrate. Therefore, the throughput of the substrate per unit time can be improved without lowering the purity of the substrate.

[Brief description of drawings]

FIG. 1 is a side sectional view of a plasma ashing apparatus showing a first embodiment (embodiment) of the present invention.

FIG. 2 is a side sectional view of a plasma ashing apparatus showing a second embodiment (embodiment) of the present invention.

FIG. 3 is a side sectional view of a plasma ashing apparatus showing a third embodiment (embodiment) of the present invention.

FIG. 4 is a comparison diagram showing ashing speeds of the plasma ashing apparatus according to the first embodiment of the present invention and the conventional example.

FIG. 5 is a side sectional view of a plasma ashing device showing a conventional example.

[Explanation of symbols]

 1A, 1B, 1C Plasma ashing device 10 Vacuum processing chamber 11 Substrate 13 Gas rectifier 14 Metal support 15 Substrate heating heater 16 Insertion fixing part 17 Exhaust port 18 Vacuum valve 19 Vacuum pump 20 Discharge tube 21 O-ring 22 Discharge plasma Region 30 Waveguide 31 Microwave power supply 32 Stub tube 33 Termination matcher 41 Cylindrical wall 42 Wall integrated with device wall 43 Substrate electrode 44 Counter electrode 45 Cylindrical wall 46 Matching box 47 RF power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshinari Takada 3313 Aruba Kyushu Co., Ltd. on Yokogawa Town, Aira District, Kagoshima Prefecture

Claims (7)

[Claims] 1. A vacuum processing chamber for accommodating a substrate to be plasma-processed, one end serving as a gas supply port for plasma generation, and the other end having a discharge tube inserted into the vacuum processing chamber. In the plasma processing apparatus, the substrate placed in the vacuum processing chamber is provided with a wall that surrounds the substrate and prevents unnecessary diffusion of gas. 2. A substrate placed in a vacuum processing chamber,
The plasma processing apparatus according to claim 1, wherein a cylindrical wall is provided so as to surround the upper side of the substrate. 3. A substrate placed in a vacuum processing chamber,
2. The plasma processing apparatus according to claim 1, wherein a wall integrated with a wall of the vacuum processing chamber is provided so as to surround the upper side of the substrate. 4. A substrate is placed on a substrate electrode installed in a vacuum processing chamber, and is electrically connected above the substrate electrode and above a counter electrode having a slit for gas permeation installed in parallel therewith. 2. The plasma processing apparatus according to claim 1, further comprising a wall for preventing unnecessary diffusion of gas in a state of surrounding the gas. 5. The plasma according to claim 1, wherein a wall provided above the substrate so as to surround the substrate is made of aluminum or aluminum oxide. Processing equipment. 6. The substrate according to claim 1, wherein a wall provided so as to surround the upper side of the substrate is made of a metal having a non-metal film adhered to the surface thereof. The plasma processing apparatus according to item 1. 7. The plasma processing apparatus according to claim 1, wherein a wall provided to surround the upper side of the substrate is made of quartz.