JP3566046B2 - Plasma processing device and sputtering device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma processing apparatus using a microwave, such as a plasma CVD apparatus and a plasma dry etching apparatus, and a sputtering apparatus.
[0002]
[Prior art]
For example, there is a plasma processing apparatus using a microwave as one of the conventional plasma processing apparatuses such as a plasma CVD apparatus, a plasma dry etching apparatus, and a plasma ashing apparatus used for a semiconductor manufacturing process. As a plasma processing apparatus of this type, a chamber that stores an object to be processed such as a glass substrate is provided with a gas supply unit that supplies a processing gas, and an object holding unit such as a stage that holds the object to be processed. Generally, a structure in which a microwave generation source for supplying microwaves is provided on a side facing a processing object with a processing space in a chamber interposed therebetween.
[0003]
In this apparatus, a microwave is supplied from a microwave generation source toward a processing object across a processing space, thereby generating plasma in the processing space on the processing object and forming a film on the processing object. And a predetermined process such as etching.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional apparatus, in order to supply the microwave and the processing gas toward the processing surface of the processing target, both the microwave generation source and the gas supply unit are connected to the processing surface of the processing target in the chamber. Since the gas supply unit is provided on the opposite side, there is a problem that there are many restrictions on the design of the apparatus, for example, the gas supply unit needs to be made of a material that easily transmits microwaves.
[0005]
Further, in the conventional apparatus, for example, when processing a large workpiece such as a glass substrate having a high flatness used for a liquid crystal display, in order to uniformly supply a processing gas to the processing surface of the workpiece. It is desirable to supply the processing gas to the processing surface in a shower form using a so-called shower head.
However, in the case of this device, in order to supply microwaves from the showerhead side, the same problem as described above arises in that a showerhead having a slightly complicated structure needs to be made of a material that can transmit microwaves. Further, since the showerhead is directly exposed to plasma, it is necessary to be made of a material having plasma resistance, and since the showerhead is also formed into a film, it is necessary to perform maintenance frequently. There was a problem.
[0006]
Therefore, as an improvement of these apparatuses, there has been proposed a configuration in which microwaves are supplied from the side surface of the chamber and processing gas is supplied in a shower shape from above the processing surface of the processing object using a shower head. ing.
However, in this apparatus, it is necessary to adopt a configuration in which the outer periphery of the chamber is surrounded by a waveguide for microwave guiding, and there is a problem that the entire apparatus becomes very large. For example, in some cases, the inner diameter of the waveguide is about five times as large as the diameter of the object to be processed, and it is very difficult to reduce the size of the device.
[0007]
The present invention has been made in view of the above circumstances, and provides a plasma processing apparatus and a sputtering apparatus using microwaves, which have less restrictions on the apparatus design and can further reduce the size of the apparatus. With the goal.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention proposes the following plasma processing apparatus and sputtering apparatus.
That is, the plasma processing apparatus of the present invention includes a chamber for accommodating an object to be processed made of a material that can transmit microwaves, a gas supply unit that supplies a processing gas into the chamber, and a material that can transmit microwaves. A processing object holding unit provided in the chamber to hold the processing object; and a micro- unit provided on a lower surface of the processing object holding unit outside the chamber to generate plasma in the chamber. A microwave supply unit that supplies a wave through the workpiece holding unit and the workpiece; and a microwave generation source connected to a lower surface of the microwave supply unit . In the present invention, the “object to be processed made of a material that can transmit microwaves” can be, for example, a glass substrate used for a liquid crystal display substrate. In addition, quartz or the like can be used as the “material that can transmit microwaves” that forms the workpiece holder.
[0009]
The plasma processing apparatus includes a microwave supply unit that supplies a microwave for generating plasma in the chamber through the workpiece holding unit and the workpiece, so that the microwave supplied by the microwave supply unit is provided. The waves generate plasma in the processing space in the chamber after passing through the workpiece holding unit and the workpiece, and perform predetermined processing on the workpiece. That is, the microwave supply means and the gas supply means can be arranged on the side facing each other with respect to the chamber for accommodating the object to be processed. With this configuration, the gas supply means needs to be made of a material that easily transmits microwaves. Is eliminated, and the configuration of the gas supply means is not restricted.
[0010]
Further, since the microwave supply means may be provided at a position where the object to be processed is held and the object to be processed in the chamber, the entire plasma processing apparatus can be prevented from being enlarged, and can be further reduced in size. Become.
Note that a radial line slot antenna may be used as the microwave supply unit. For details on this radial line slot antenna, see Masaki Hirayama and Tadahiro Omi, "Microwave-excited high-density plasma apparatus for high-quality film formation, 30th Ultra LSI Ultra Clean Technology Symposium, pp. 49-59, (1997)". Has been stated.
The gas supply means may be configured to supply the processing gas from a direction facing the object to be processed. Specifically, a shower head or the like can be used.
[0011]
The sputtering apparatus of the present invention includes a chamber for accommodating an object to be processed made of a material that can transmit microwaves, a gas supply unit that supplies a processing gas into the chamber, and a material that can transmit microwaves. A processing object holding portion provided in the chamber and holding the processing object, and a microwave for generating plasma in the chamber , provided on a lower surface of the processing object holding portion outside the chamber , Microwave supply means for supplying the object to be processed through the object holding part and the object to be processed, a microwave source connected to the lower surface of the microwave supply means, and a processing surface of the object to be processed in the chamber facing the object. And a target irradiated with the charged particles by the plasma, and an electromagnetic wave having a lower frequency than the microwave is supplied to the target. Those provided with the electromagnetic wave supplying means.
[0012]
In this sputtering apparatus, the microwave supply means for supplying the microwave for generating plasma in the chamber through the workpiece holding unit and the workpiece is provided, so that the microwave supplied by the microwave supply means is provided. The wave generates plasma in the processing space in the chamber after penetrating the workpiece holder and the workpiece, irradiates the target with charged particles by the plasma, and performs sputtering on the workpiece.
[0013]
This eliminates the need for the gas supply unit to be made of a material that easily transmits microwaves, and does not restrict the configuration of the gas supply unit. In addition, since the microwave supply means may be provided at a position where the object to be processed is held in the chamber and at the position where the object to be processed is transmitted, the entire sputtering apparatus can be prevented from increasing in size and can be further reduced in size.
As the microwave supply means, a radial line slot antenna may be used as in the above case.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a plasma processing apparatus and a sputtering apparatus of the present invention will be described with reference to the drawings.
[0015]
[First Embodiment]
FIG. 1 is a configuration diagram illustrating a plasma processing apparatus according to a first embodiment of the present invention. In the drawing, reference numeral 1 denotes a glass substrate (a processing target made of a material that can transmit microwaves); Reference numeral 3 denotes a gas supply pipe (gas supply means) provided on one side wall 2a of the chamber 2 for supplying a processing gas 4 into the chamber 2. Reference numeral 5 denotes an exhaust port provided on the other side wall 2b of the chamber 2 for discharging exhaust gas 6 generated in the chamber 2.
[0016]
Reference numeral 7 denotes a bottom plate (workpiece holding portion) constituting the bottom of the chamber 2, which is made of quartz (a material that can transmit microwaves) and holds the glass substrate 1. Reference numeral 8 denotes a radial line slot antenna (RLSA; microwave supply means) which is provided on the lower surface of the bottom plate 7 and supplies microwaves for generating plasma 9 in the chamber 2 through the bottom plate 7 and the glass substrate 1. FIG. 2 is a plan view of the radial line slot antenna 8. As shown in this figure, a large number of slots 12, 12,... Are concentrically arranged in a radial line slot antenna 8, and circularly polarized microwaves generated from these slots are introduced into the chamber 2, and The plasma 9 is excited by this electric field.
[0017]
Reference numeral 10 denotes a microwave generation source which is connected to the lower surface of the radial line slot antenna 8 and includes a waveguide for supplying a microwave 11 and the like.
The height of the top plate 2c of the chamber 2 from the bottom plate 7 is set to a height sufficient to prevent reaction products generated by the plasma 9 from adhering.
[0018]
In this plasma processing apparatus, a predetermined processing gas 4 is supplied into a chamber 2 from a gas supply pipe 3, and a microwave 11 is supplied from a radial line slot antenna 8 to a processing space in the chamber 2 through a bottom plate 7 and a glass substrate 1. The plasma 9 is generated by the supply, and a predetermined process is performed on the glass substrate 1. Since the radial line slot antenna 8 can emit the microwaves 11 toward the processing space in the chamber 2 in parallel, the plasma 9 does not spread more than necessary, and the portions other than the glass substrate 1 are directly contacted with the plasma 9. For example, there is little restriction on the material of the side wall of the chamber 2 such that a material having high plasma resistance must be used, and the degree of freedom in apparatus design can be increased. .
[0019]
In particular, when the glass substrate 1 having a larger area than the area where the plasma 9 spreads is used, only the glass substrate 1 is directly exposed to the plasma 9. Very little removal of the film-forming material adhered to the inner wall is required, and maintenance becomes very simple.
[0020]
In this plasma processing apparatus, various processes such as oxidation, nitridation, dry etching, film formation, and heat treatment can be performed by changing the gas type of the processing gas 4. For example, as the heat treatment, heating by irradiation of charged particles from the plasma 9, heating by absorbing a part of the microwave 11, or the like can be used. In particular, if a material that easily absorbs the microwave 11 is patterned on the surface of the object to be processed such as the glass substrate 1, the patterned portion can be selectively heated. If this heat treatment is used in combination with the film formation process, selective film formation and selective crystallization can be performed.
[0021]
According to the plasma processing apparatus of the present embodiment, the bottom of chamber 2 is constituted by bottom plate 7 made of quartz, and microwave 11 for generating plasma 9 in chamber 2 is formed on the lower surface of bottom plate 7 and bottom plate 7. Since the radial line slot antenna 8 supplied through the glass substrate 1 is provided, it is not necessary to configure the portion other than the bottom of the chamber 2, the gas supply pipe 3, and the exhaust port 5 with a material through which microwaves can easily pass. The parts other than the bottom, the gas supply pipe 3 and the exhaust port 5 can be easily designed, and the restrictions on the design can be eliminated. Further, since the radial line slot antenna 8 is provided on the bottom plate 7 of the chamber 2, the whole apparatus can be further reduced in size.
[0022]
In the plasma processing apparatus of the present embodiment, the bottom of the chamber 2 is a bottom plate 7 made of quartz, and the radial line slot antenna 8 is provided on the lower surface of the bottom plate 7. The plasma 9 is generated in the chamber 2. And the shape of the bottom plate 7, the holding shape of the glass substrate, the shape of the radial line slot antenna 8, and the like are limited to the above-described embodiment. Instead, it can be changed to various shapes.
[0023]
[Second embodiment]
FIG. 3 is a configuration diagram showing a plasma processing apparatus according to a second embodiment of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In FIG. 3, reference numeral 21 denotes a large glass substrate (object to be processed made of a material capable of transmitting microwaves), 22 denotes a large chamber for accommodating the glass substrate 21, and 23 denotes a central part of a top plate 22 c of the chamber 22. A shower head (gas supply means) 24 for supplying the processing gas 4 into the chamber 22 is a substrate loading / unloading port provided on the side wall 22 a of the chamber 22 for loading / unloading the glass substrate 21 into / from the chamber 22.
[0024]
Reference numeral 25 denotes a bottom plate (substrate holding portion) having a substantially U-shaped cross section in which the upper surface constituting the bottom of the chamber 22 has a flat surface, and is made of quartz (a material that can transmit microwaves). The glass substrate 21 is held on the upper surface.
The number and position of the gas blowing holes 26, 26,... Of the shower head 23 are set so that the processing gas 4 is blown out uniformly and parallel to the surface of the glass substrate 21. The height of the bottom plate 25 from the upper surface is set to a height sufficient to prevent reaction products generated by the plasma 9 from adhering.
[0025]
In particular, in a plasma CVD apparatus or a dry etching apparatus which needs to supply a large amount of a reaction gas, gas supply by a shower head is effective to cope with a large substrate.
In this plasma processing apparatus, the glass substrate 21 is loaded into the chamber 22 from the substrate loading / unloading port 24, and a predetermined processing gas 4 is directed to the surface of the glass substrate 21 from the gas outlets 26, 26,. Plasma 9 is generated by supplying microwaves 11 from the radial line slot antenna 8 to the processing space in the chamber 22 through the upper surface of the bottom plate 25 and the glass substrate 21, thereby generating plasma 9. 21 is subjected to a predetermined process. The processed glass substrate 21 is unloaded from the chamber 22 through the substrate loading / unloading port 24.
[0026]
According to the plasma processing apparatus of the present embodiment, there is no restriction on the configuration of the apparatus, which is conventionally required, such as forming the shower head 23 from a material that transmits microwaves. In addition, since a space around the glass substrate 21 is sufficient as long as a space for obtaining a sufficient conductance for exhausting gas can be secured, the size of the device can be made much smaller than that of a conventional device.
[0027]
Further, in the conventional apparatus, there have been problems such as the plasma resistance of the shower head is required and high frequency maintenance is required. However, in this apparatus, the bottom plate 25 of the gas blowing holes 26, 26,. The height from the upper surface is set high enough to prevent the reaction products generated by the plasma 9 from adhering, so that these problems can be solved, the degree of freedom in design can be increased, and a more optimal apparatus design can be achieved. Will be possible.
[0028]
[Third Embodiment]
FIG. 4 is a configuration diagram showing a sputtering apparatus according to a third embodiment of the present invention. In FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In FIG. 4, reference numeral 31 denotes a chamber for accommodating the glass substrate 1, 32 denotes a backing plate fitted into a central portion of a top plate 31 c of the chamber 31, and 33 denotes a lower surface of the backing plate 32 so as to face a processing surface of the glass substrate 1. A target 34 made of, for example, aluminum (Al) is installed on the backing plate 32. An RF power source (electromagnetic wave supply means) is connected to the backing plate 32.
[0029]
Although the frequency of the RF power supply 34 is generally easy to handle at 13.56 MHz, it is better to set the frequency for each material constituting the target 33 so as to obtain the energy required for sputtering.
As the microwave 11 on the glass substrate 1 side, one having a frequency of several GHz or more is usually used. However, in order to obtain a higher quality film, atoms to be formed without causing damage can cause migration. Since it is necessary to provide sufficient energy, a higher frequency (for example, 8 GHz or more) is desirable.
[0030]
In this sputtering apparatus, a predetermined processing gas 4 such as argon (Ar) is supplied into a chamber 31 from a gas supply pipe 3, and a processing space in the chamber 31 is passed through a bottom plate 7 and a glass substrate 1 from a radial line slot antenna 8. The plasma 9 is generated by supplying a microwave 11 to the target, and an electromagnetic wave having a frequency lower than that of the microwave 11 is supplied from the RF power source 34 to the target 33 via the backing plate 32 so that the charged particles by the plasma 9 are targeted. The glass substrate 1 is sputtered by Al atoms or the like generated from the target 33.
[0031]
According to the sputtering apparatus of the present embodiment, the microwaves 11 are supplied from the radial line slot antenna 8 to the processing space in the chamber 31 through the bottom plate 7 and the glass substrate 1. The gas supply pipe 3 and the exhaust port 5 do not need to be made of a material through which microwaves can easily pass, so that parts other than the bottom of the chamber 31 and the gas supply pipe 3 and the exhaust port 5 can be easily designed, and the apparatus design can be improved. The restriction can be eliminated.
[0032]
Further, since the radial line slot antenna 8 is provided on the bottom plate 7 of the chamber 31, it is possible to prevent the chamber 31 from being enlarged, and to further reduce the size of the entire apparatus.
Further, since the microwave 11 is applied from the glass substrate 1 side, high-density plasma, low electron temperature, and low ion energy, which are characteristics of microwave plasma, can be used for film formation. On the other hand, since an electromagnetic wave having a lower frequency than the microwave 11 is applied to the target 33, ion energy required for sputtering can be obtained.
[0033]
【The invention's effect】
As described above in detail, according to the plasma processing apparatus of the present invention, the plasma processing apparatus of the present invention includes a microwave supply unit that supplies a microwave for generating plasma in the chamber through the workpiece holding unit and the workpiece. Therefore, the gas supply means does not need to be made of a material through which microwaves can easily pass, and there is no need to restrict the structure of the gas supply means.
In addition, since the microwave supply means may be provided at a position where the object to be processed is held by the object to be processed in the chamber, the entire plasma processing apparatus can be downsized.
[0034]
According to the sputtering apparatus of the present invention, since the microwave supply means for supplying the microwave for generating the plasma in the chamber through the workpiece holding unit and the workpiece is provided, the microwave is transmitted through the gas supply means. There is no need to use a material that is easy to use, and there is no need to restrict the configuration of the gas supply unit. Further, since the microwave supply means may be provided at the position where the object to be processed is held in the chamber and the object to be processed, the entire sputtering apparatus can be downsized.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a plasma processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a plan view showing a radial line slot antenna used in the plasma processing apparatus.
FIG. 3 is a sectional view showing a plasma processing apparatus according to a second embodiment of the present invention.
FIG. 4 is a sectional view showing a sputtering apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
1,21 glass substrate (workpiece made of material that can transmit microwaves)
2,22,31 Chamber 3 Gas supply pipe (gas supply means)
4 Processing gas 5 Exhaust port 6 Exhaust gas 7,25 Bottom plate (workpiece holding part)
8 Radial line slot antenna (microwave supply means)
9 Plasma 10 Microwave generation source 11 Microwave 23 Shower head (gas supply means)
24 Substrate loading / unloading port 33 Target 34 RF power supply (electromagnetic wave supply means)

Claims (7)

A chamber containing an object to be processed made of a material that can transmit microwaves,
Gas supply means for supplying a processing gas into the chamber;
An object-to-be-processed holding part, which is made of a material that can transmit microwaves and is provided in the chamber and holds the object to be processed,
Microwave supply means provided on the lower surface of the processing object holding unit outside the chamber, for supplying a microwave for generating plasma in the chamber through the processing object holding unit and the processing object,
A microwave generation source connected to the lower surface of the microwave supply means,
A plasma processing apparatus comprising: 2. The plasma processing apparatus according to claim 1, wherein the workpiece holding unit forms a bottom of the chamber. 3. The plasma processing apparatus according to claim 1, wherein the microwave supply means is a radial line slot antenna. 2. The plasma processing apparatus according to claim 1, wherein the gas supply unit is configured to supply the processing gas from a direction facing the workpiece. 3. A chamber containing an object to be processed made of a material that can transmit microwaves,
Gas supply means for supplying a processing gas into the chamber;
An object-to-be-processed holding part, which is made of a material that can transmit microwaves and is provided in the chamber and holds the object to be processed,
Microwave supply means provided on the lower surface of the processing object holding unit outside the chamber, for supplying a microwave for generating plasma in the chamber through the processing object holding unit and the processing object,
A microwave generation source connected to the lower surface of the microwave supply means,
A target that is installed in the chamber so as to face a processing surface of the object to be processed, and is irradiated with charged particles by the plasma;
Electromagnetic wave supply means for supplying an electromagnetic wave having a lower frequency than the microwave to the target,
A sputtering apparatus comprising: 6. The sputtering apparatus according to claim 5, wherein the workpiece holding part forms a bottom of the chamber. The sputtering apparatus according to claim 5, wherein the microwave supply means is a radial line slot antenna.

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