JP2002043289A - Method and device for plasma processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for plasma processing capable of reducing contamination and dust generated by metallic parts constituting a gas feeding means and improving the uniformity of processing by evenly feeding the gas. SOLUTION: In the method and device for plasma processing, which processes a substrate on an electrode 5 by generating plasma 9 by introducing an electromagnetic wave into the container 1 through dielectric plates 4 by applying high frequency voltage from a high frequency power source 3 to a coil or antenna 2 while controlling pressure inside a vacuum container 1 to a prescribed value by exhausting while feeding gas into the container 1, gas is uniformly introduced into the container 1 through gas feeding paths 11 formed inside the plurality of plates 4 arranged so as to correspond to a large area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and apparatus for dry etching and the like, and more particularly to a high frequency induction type plasma processing method and apparatus.

[0002]

2. Description of the Related Art In recent years, it has been required to realize high aspect ratio processing in dry etching technology in response to miniaturization of semiconductor elements and liquid crystal driving elements. Therefore, in plasma CVD technology, high aspect ratio processing is required. In order to realize embedding, it is required to perform plasma processing in a higher vacuum.

For example, in the case of dry etching, when high-density plasma is generated in a high vacuum, the probability that ions collide with neutral gas particles and the like in an ion sheath formed on the surface of a substrate to be processed is reduced. Since the directionality of ions is aligned toward the substrate to be processed, and the ionization degree is high, the ratio of the incident particle flux of ions to the neutral radical reaching the substrate to be processed increases. Therefore, the etching anisotropy is enhanced, and processing with a high aspect ratio becomes possible.

As one type of plasma processing apparatus capable of generating high-density plasma in a high vacuum, a high-frequency induction system in which electromagnetic waves are introduced into a vacuum vessel by applying a high-frequency voltage to a coil or an antenna to generate plasma. Plasma processing apparatus. This type of plasma processing apparatus generates a high-frequency magnetic field in a vacuum vessel, generates an induction magnetic field in the vacuum vessel using the high-frequency magnetic field, accelerates electrons, and generates plasma. High-density plasma can be generated even in a high vacuum, and a sufficient processing speed can be obtained.

FIG. 3 shows an example of a high frequency induction type plasma processing apparatus. By evacuating while supplying an appropriate gas into the vacuum container 21 and applying a high-frequency voltage to the coil or the antenna 22 from the high-frequency power source 23 while maintaining the inside of the vacuum container 21 at an appropriate pressure, the dielectric plate 24 Then, an electromagnetic wave is introduced into the vacuum vessel 21 to generate plasma 31 in the vacuum vessel 21 as described above, and the etching, deposition, and surface treatment are performed on the substrate 26 placed on the electrode 25 of the vacuum vessel 21. Plasma treatment such as reforming can be performed. At this time, as shown in FIG. 3, by applying a high-frequency voltage to the electrode 25 from the electrode high-frequency power supply 27,
The ion energy reaching the substrate 26 to be processed can be controlled. Reference numeral 28 denotes a support frame formed of a metal lattice such as aluminum or stainless steel for supporting a plurality of dielectric plates 24, and reference numeral 30 denotes a gas supply passage 2 formed in the support frame 28.
9 and the like.

[0006]

However, in the above-mentioned conventional construction, the support frame 28 in which the gas supply passage 29 constituting the gas supply means 30 is formed is made of a metal such as aluminum or stainless steel. During stacking, problems such as metal contamination and dust generation due to metal corrosion may occur on the substrate 25 to be processed. There is a method of solving the problem by periodically replacing these parts. However, not only does the replacement require time, but the gas supply means 30 is a factor that greatly affects the processing performance. You.

Further, according to the gas supply means 30 composed of metal parts, when the electromagnetic wave generated by the coil or the antenna 22 is introduced into the vacuum vessel 21,
There is a possibility that the energy output from the power supply will be significantly attenuated. Therefore, the gas supply means 3 extends over a wide area.
0 becomes difficult, and as a result, there is a problem that uniformity of processing performance such as etching cannot be improved.

In addition, since the reaction product directed to the dielectric plate side adheres to the dielectric plate during the processing, when the integrated processing time reaches a predetermined time, the efficiency of introduction of electromagnetic waves into the vacuum vessel 21 deteriorates. It is necessary to remove the dielectric plate 24 and perform maintenance, and there is a problem that the time required for maintenance is long and the operation rate of the apparatus is reduced.

In view of the above problems, the present invention provides a plasma processing method capable of reducing contamination and dust generation by metal parts constituting a gas supply means, and improving uniformity of processing performance by uniform gas supply. It is intended to provide a device.

[0010]

According to the plasma processing method of the present invention, a dielectric plate is applied by applying a high-frequency voltage to a coil or an antenna while controlling the gas to a predetermined pressure while evacuating while supplying a gas into a vacuum vessel. In a plasma processing method for generating a plasma by introducing an electromagnetic wave into a vacuum vessel through a substrate and processing the substrate, a gas is introduced into the vacuum vessel through the inside of the dielectric plate, and the dielectric plate is made of a dielectric material. Since gas is supplied through the interior of the vacuum vessel, dust generation due to metal contamination and corrosion can be prevented, and since the gas supply means is made of a dielectric, the output energy of the high-frequency power supply can be kept The gas flow can be controlled uniformly, and uniform processing can be performed efficiently.

Further, when a gas is introduced into a vacuum vessel through the inside of each of a plurality of dielectric plates arranged to correspond to a large-area substrate, the vacuum is applied from the plurality of dielectric plates to a large-area substrate. The gas can be uniformly supplied into the container, and the uniformity of the processing speed can be greatly improved even in the case of a substrate having a large area.

Further, according to the plasma processing method of the present invention, a second dielectric plate is arranged between the dielectric plate and the substrate separately from the dielectric plate,
The space between the dielectric plate and the second dielectric plate is evacuated through an exhaust passage in the dielectric plate. During the process, the reaction product directed to the dielectric plate side adheres to the second dielectric plate, and is attached to the dielectric plate. Since the second dielectric plate does not adhere, only the second dielectric plate needs to be replaced at the time of maintenance, the maintenance time can be reduced, and the space between the dielectric plate and the second dielectric plate is evacuated when the inside of the vacuum vessel is evacuated. The second dielectric plate can be prevented from being broken by a pressure difference generated between the inside of the vacuum vessel and the space.

Further, the plasma processing apparatus of the present invention provides an electromagnetic wave in a vacuum vessel via a vacuum vessel, gas supply means for supplying a process gas into the vacuum vessel, and a dielectric plate provided on a wall of the vacuum vessel. A coil or antenna to be introduced,
In a plasma processing apparatus provided with a high-frequency power supply for applying a high-frequency voltage to a coil or an antenna and an electrode for mounting a substrate in a vacuum vessel, a gas supply means is disposed inside a dielectric plate, Is one in which a plurality of dielectric plates are arranged to correspond to a large-area substrate, and gas supply means are arranged inside each of the plurality of dielectric plates. it can.

In the plasma processing apparatus according to the present invention, a second dielectric plate is disposed between the dielectric plate and the dielectric plate and the substrate, and an exhaust passage for exhausting a space between the dielectric plate and the second dielectric plate is provided. It is arranged in a dielectric plate, and the effect can be obtained by implementing the above method.

Further, when the material of the dielectric plate or the second dielectric plate is glass, ceramic or polyimide resin, properties such as electrical insulation, plasma resistance, chemical resistance, heat resistance and corrosion resistance can be satisfied. It is suitable. In particular, glass is quartz glass, ceramic is alumina, zirconia,
Vespel (DuPont) is suitable for the polyimide resin.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plasma processing apparatus according to the present invention will be described below with reference to FIGS.

(First Embodiment) First, a first embodiment will be described with reference to FIG. In FIG. 1, when a high-frequency voltage is applied from a high-frequency power source 3 to a coil or an antenna 2 while evacuating while supplying an appropriate gas into the vacuum container 1 and maintaining the inside of the vacuum container 1 at an appropriate pressure, the dielectric plate 4 An electromagnetic wave is introduced into the vacuum vessel 1 through the, and a plasma 9 is generated in the vacuum vessel 1, and etching, deposition, and deposition are performed on the substrate 6 placed on the electrode 5 of the vacuum vessel 1.
Plasma treatment such as surface modification can be performed. At this time, as shown in FIG.
By applying a high-frequency voltage, the ion energy reaching the substrate 6 to be processed can be controlled. 8
Is a lattice support frame made of metal such as aluminum or stainless steel, which is provided to support a plurality of dielectric plates 4 in order to support the large-area substrate 6 to be processed.

Reference numeral 10 denotes a gas supply passage 11 formed in the dielectric plate 4 and a gas communication passage formed in the support frame 8 so as to communicate the gas supply passage 11 with an external gas supply source (not shown). The gas supply passage 11 is formed in the dielectric plate 4 so as to uniformly supply gas from above to below into the vacuum vessel 1.

In the above configuration, the gas is evacuated while supplying an appropriate gas into the vacuum vessel 1, and a high-frequency voltage is applied to the coil or the antenna 2 from the high-frequency power supply 3 while maintaining the inside of the vacuum vessel 1 at an appropriate pressure. The dielectric plate 4
An electromagnetic wave is introduced into the vacuum vessel 1 through the above, and a plasma 9 is generated in the vacuum vessel 1 as described above, and the processing target substrate 6 placed on the electrode 5 of the vacuum vessel 1 is etched.
Plasma treatment such as deposition and surface modification can be performed.

In the above plasma treatment, gas is supplied through a gas supply passage 11 formed inside a dielectric plate 4 made of a dielectric material of a high-purity material such as glass, ceramic or polyimide resin. Since the gas supply passage 11 is formed in the dielectric plate 4, the output energy of the high-frequency power source 3 is not lost, and the gas supply passage 11 can be freely disposed in the plurality of dielectric plates 4. Therefore, the gas flow in the vacuum vessel 1 can be controlled to greatly improve the uniformity of the processing speed.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. Note that the same components as those of the first embodiment described with reference to FIG. 1 are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

In FIG. 2, a second dielectric plate 13 is disposed with a space 14 opened in the dielectric plate 4 inside the vacuum vessel 1.
Further, in order to exhaust the space 14 between the dielectric plate 4 and the second dielectric plate 13, an exhaust passage 15 and a valve as necessary are provided in the dielectric plate 4, and the exhaust passage 15 is provided with an exhaust means (not shown). An exhaust passage 16 communicating with the support frame 8 is provided in the support frame 8.

According to the above configuration, since the second dielectric plate 13 is disposed between the dielectric plate 4 and the substrate 6 to be processed,
The discharge space in which the plasma 9 is generated is separated from the dielectric plate 4 by the dielectric plate 13, so that reaction products can be prevented from adhering to the dielectric plate 4. Further, before or at the same time as the inside of the vacuum vessel 1 is evacuated from the atmospheric pressure, the exhaust passage 15 is evacuated.
By exhausting the space 14 through the opening, the second dielectric plate 13 can be prevented from being broken.

[0024]

According to the plasma processing method and apparatus of the present invention, gas is supplied through the inside of the dielectric plate made of a dielectric as described above, so that dust generation due to metal contamination and corrosion can be prevented. Further, since the gas supply means is made of a dielectric material, the gas flow in the vacuum vessel can be controlled uniformly without losing the output energy of the high frequency power supply, and the uniform processing can be performed efficiently.

Further, when a gas is introduced into the vacuum vessel through the inside of each of a plurality of dielectric plates arranged to correspond to a large-area substrate, the vacuum is applied from the plurality of dielectric plates to a large-area substrate. The gas can be uniformly supplied into the container, and the uniformity of the processing speed can be greatly improved even in the case of a substrate having a large area.

According to the plasma processing method and apparatus of the present invention, since the second dielectric plate is disposed between the dielectric plate and the substrate separately from the dielectric plate, the second dielectric plate faces the dielectric plate during processing. Since the reaction product adheres to the second dielectric plate, only the second dielectric plate needs to be replaced at the time of maintenance, the maintenance time can be shortened, and the above-described dielectric plate and the second dielectric plate are evacuated when the inside of the vacuum vessel is evacuated. Is exhausted through the exhaust passage in the dielectric plate, it is possible to prevent the second dielectric plate from being broken by a pressure difference generated between the inside of the vacuum vessel and the above-mentioned space.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a plasma processing apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of a second embodiment of the plasma processing apparatus of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Coil or antenna 3 High frequency power supply 4 Dielectric plate 5 Electrode 6 Substrate to be processed 10 Gas supply means 11 Gas supply passage 13 Second dielectric plate 14 Space 15 Exhaust passage

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/205 H05H 1/46 L H05H 1/46 H01L 21/302 B F-term (Reference) 4K030 EA06 EA11 FA04 KA20 KA46 4K057 DA01 DD01 DM05 DM10 DM19 DM37 5F004 AA01 AA16 BA20 BB13 BB28 BC03 5F045 AA08 BB10 BB14 EF20 EH02 EH03 EH04 EH08 EH11

Claims (8)

[Claims] 1. An electromagnetic wave is introduced into a vacuum vessel through a dielectric plate by applying a high-frequency voltage to a coil or an antenna while controlling a predetermined pressure while exhausting the gas while supplying the gas into the vacuum vessel. A plasma processing method for generating plasma by means of a plasma processing and processing a substrate, wherein a gas is introduced into a vacuum vessel through the inside of a dielectric plate. 2. The plasma processing method according to claim 1, wherein a gas is introduced into the vacuum vessel through the inside of each of a plurality of dielectric plates disposed so as to correspond to a substrate having a large area. 3. An electromagnetic wave is introduced into a vacuum vessel via a dielectric plate by applying a high-frequency voltage to a coil or an antenna while controlling the pressure to a predetermined pressure while supplying and exhausting gas into the vacuum vessel. In the plasma processing method of generating a plasma by means of a substrate and processing the substrate, a second dielectric plate is disposed between the dielectric plate and the substrate separately from the dielectric plate, and a space between the dielectric plate and the second dielectric plate is insulated. A plasma processing method characterized by exhausting air through an exhaust passage in a plate. 4. A vacuum vessel, gas supply means for supplying a process gas into the vacuum vessel, a coil or an antenna for introducing electromagnetic waves into the vacuum vessel via a dielectric plate provided on a wall surface of the vacuum vessel, and a coil. Alternatively, in a plasma processing apparatus provided with a high-frequency power supply for applying a high-frequency voltage to an antenna and an electrode for mounting a substrate in a vacuum vessel, a gas supply means is provided inside a dielectric plate. apparatus. 5. The plasma processing according to claim 4, wherein a plurality of dielectric plates are arranged so as to correspond to a substrate having a large area, and gas supply means is provided inside each of the plurality of dielectric plates. apparatus. 6. A vacuum vessel, gas supply means for supplying a process gas into the vacuum vessel, a coil or an antenna for introducing electromagnetic waves into the vacuum vessel via a dielectric plate provided on a wall of the vacuum vessel, and a coil. Alternatively, in a plasma processing apparatus provided with a high-frequency power supply for applying a high-frequency voltage to an antenna and an electrode for mounting a substrate in a vacuum vessel, a second dielectric plate is provided between the dielectric plate and the dielectric plate separately from the dielectric plate. Place,
An exhaust passage for exhausting a space between a dielectric plate and a second dielectric plate is provided in the dielectric plate. 7. The material of the dielectric plate is glass, ceramic or polyimide resin.
7. The plasma processing apparatus according to any one of claims 1 to 6. 8. The plasma processing apparatus according to claim 6, wherein the material of the second dielectric plate is glass, ceramic, or polyimide resin.