JPH09153486A - Plasma processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing method and a device which are capable of forming a thin film of high quality on a substrate of large area and carrying out etching and a surface treatment so as to realize the manufacture of a liquid crystal display panel of large area or multiple chamfers, a liquid crystal display device high in throughput and yield, and a semiconductor integrated circuit device or the like. SOLUTION: A plasma processing device 1 is equipped with a pair of paallel plates 3a and 3b, a microwave waveguide tube 4a (and/or 4b) used for introducing microwaves between the parallel plates 3a and 3b, and a reactive gas introducing path 5 which introduces reactive gas between the parallel plates 3a and 3b in a vacuum chamber 2. By the use of the plasma processing device 1, a stabstrate 10 is placed on the parallel plate 3a, reactive gas introduced between the parallel plates 3a and 3b is turned into plasma by microwaves introduced between them to etch the substrate 10 with plasma.

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 used for manufacturing a liquid crystal display device, a semiconductor integrated circuit device or the like, and a plasma processing apparatus for realizing the method, and more particularly to forming a high quality thin film on a large area substrate. The present invention relates to a plasma processing method and a plasma processing apparatus used in a process such as etching or surface treatment.

[0002]

2. Description of the Related Art Conventionally, plasma processing has been widely used for manufacturing liquid crystal display devices or semiconductor integrated circuit devices represented by ICs and LSIs. For example, in the manufacture of an active matrix driving type liquid crystal display device including a thin film transistor, plasma treatment is used for forming a thin film on a substrate, etching during pattern formation, surface treatment such as surface cleaning, and resist removal after lithography. More specifically, when forming an amorphous (or polycrystalline) silicon thin film, a gate oxide film, a metal film for electrodes, etc. on a glass substrate, chemical vapor deposition using plasma (Plasma Enhanced CVD; , PCVD) or sputter film formation, and reactive ion etching (Reactive Ion Etching;
Hereinafter, plasma etching such as RIE) or reactive ion beam etching (hereinafter referred to as RIBE) is performed. Plasma processing is similarly used in the manufacture of semiconductor integrated circuit devices, and a semiconductor substrate such as silicon or gallium arsenide is used as the substrate.

As typical plasma processing, there are two conventional techniques. In the first conventional technique, the reactive gas is turned into plasma by a high frequency of 13.56 MHz, which is usually introduced between a pair of parallel plate electrodes, and plasma treatment is performed on a substrate placed on one of the electrodes. In the second conventional technique, the plasma generation chamber and the plasma processing chamber in which the substrate is installed are separated, and are usually 2.45 placed in the plasma generation chamber.
The reactive gas is made into plasma by the microwave of GHz,
The active particles in the plasma are guided onto the substrate in the plasma processing chamber by an electric field, a magnetic field or diffusion to perform the plasma processing.

The two conventional techniques will be described below with reference to FIGS. 7 and 8. FIG. 7 is a schematic configuration diagram showing a parallel plate type plasma processing apparatus 51 that realizes the first conventional technique. Parallel plate type plasma processing apparatus 51
Is an electrically grounded vacuum container 52, a pair of parallel plate electrodes 53a and 53b parallel to each other, and a frequency of 13.56M.
A high frequency power supply 54 of Hz, a matching circuit 55, and a reactive gas introducing pipe 56 are provided as main components.

The parallel plate type plasma processing apparatus 51 is
When used as a CVD apparatus, the substrate 57 is placed on the electrode 53a that is electrically grounded, and the high frequency power supply 54 is connected to the electrode 53b side via the matching circuit 55. As a result, the voltage drop due to self-bias during plasma generation is smaller on the electrode 53a side than on the electrode 53b side, and substrate surface damage due to accelerated ions is reduced to some extent. However, the voltage drop is also a function of input high-frequency power, reactive gas species and pressure (in other words, plasma density), etc., and complete independent control thereof is difficult.

The parallel plate type plasma processing apparatus 51 is connected to the PCV
Used as a D device, a silicon dioxide (SiO ₂ ) film is formed as follows, for example. Using a mixed gas of monosilane (SiH ₄ ) and nitrous oxide (N ₂ O) as a reactive gas, the mixing ratio is set to an N ₂ O rich state such as SiH ₄ : N ₂ O = 1: 15, After the inside of the vacuum container 52 is evacuated to a high vacuum (for example, back pressure of 10 ⁻⁴ Pa or less), the reactive gas is introduced through the reactive gas introduction pipe 56. The gas pressure in the vacuum container 52 is kept constant (for example, 100 Pa) by controlling the intake speed and exhaust speed of the gas to be introduced.
And plasma is generated by applying a high frequency between the parallel plate electrodes 53a and 53b, and the active particles of silicon and oxygen from the plasma chemically react with each other on the surface of the substrate 57 or in the vicinity of the surface to form an SiO ₂ film. It is formed. At this time, impedance matching is achieved by adjusting the matching circuit 55.

In the case of using a high frequency represented by a frequency of 13.56 MHz, the lower limit of the gas pressure at which plasma can be generated is usually about ten and several Pa, and the plasma generation state can be maintained up to several Pa. A magnetic field may be used together for the purpose of maintaining the plasma generation state at a lower gas pressure or for increasing the plasma density at the same gas pressure. For example, a pair of concentric ring-shaped magnets 58 or electromagnetic coils are installed on the back surface side of the electrode 53b, and the electrode 53b
The above object can be achieved by forming the magnetic field 59 near the surface. This is due to the presence of the magnetic field 59.
This is because the rotational motion component is added to the electrons in the plasma that traverses the plasma, which increases the probability of collision with neutral atoms and ions.

When the parallel plate type plasma processing apparatus 51 is used as a sputtering film forming apparatus, the electrode 53b is replaced with a target made of a desired material, or the target is placed on the electrode 53b. Then, an inert gas such as argon (Ar) is introduced from the reactive gas introducing tube 56, and the target particles physically sputtered by the ions in the inert gas plasma (hereinafter referred to as sputtering ions) are used to form the substrate. Thin film deposition on 57 can be performed. Acceleration of sputtering ions onto the target is performed by a voltage drop due to self-bias on the electrode 53b side, and the voltage drop is controlled by the applied high frequency power and gas pressure, but a DC bias is applied to the electrode 53b to positively. It may increase the voltage drop. Further, the so-called magnetron sputtering film formation is one in which the magnetic field 59 from the ring-shaped magnet 58 is also used to increase the sputtering efficiency (in other words, the deposition rate).

The parallel plate type plasma processing apparatus 51 is RIE
When used as a device, the substrate 57 is placed on the electrode 53b. Then, a reactive gas for etching (hereinafter referred to as an etching gas) is introduced from the reactive gas introducing pipe 56,
The substrate 57 is etched using both physical sputtering by accelerated ions from etching gas plasma and chemical etching by active particles. The effect of physical sputtering by accelerated ions enables anisotropic etching such as vertical etching as compared with the case of only chemical etching. The acceleration of the ions is controlled in the same manner as in the case of the sputtering film formation. For example, in plasma processing such as surface cleaning and resist removal, the acceleration voltage is suppressed as compared with the case of anisotropic etching. Etc. are controlled. In addition, a magnetic field 59 from the ring-shaped magnet 58 may be used together to increase the etching rate. As an etching gas, chlorine gas is used for semiconductors such as silicon and gallium arsenide, fluorine gas is used for silicon oxide film and nitride film, and oxygen gas is used for carbon polymer resist.

FIG. 8 is a schematic configuration diagram showing a microwave excitation type plasma processing apparatus 61 which realizes the second conventional technique. The microwave excited plasma processing apparatus 61 includes a plasma generation chamber 62, a plasma processing chamber 63, a substrate holder 6
4. A microwave waveguide 65 and a reactive gas introducing pipe 66 as means for inputting a microwave having a frequency of 2.45 GHz are provided as main components.

The microwave-excited plasma processing apparatus 6
When 1 is used as a PCVD apparatus and a SiO ₂ film is formed on the substrate 67, a second reactive gas introduction pipe 68 for introducing a reactive gas to the vicinity of the surface of the substrate holder 64 is further provided. Then, after the plasma generation chamber 62 and the plasma processing chamber 63 are evacuated to a high vacuum (for example, a back pressure of 10 ⁻⁴ Pa or less), oxygen (O ₂ ) gas is supplied from the reactive gas introduction pipe 66 to the second reactivity. SiH ₄ is introduced from each gas introduction pipe 68. The O ₂ gas introduced into the plasma generation chamber 62 has a frequency of 2.45 GHz introduced from the waveguide 65.
Is turned into plasma by the microwave.

In the case of using the microwave represented by the frequency of 2.45 GHz, the lower limit of the gas pressure capable of maintaining the plasma generation state can be set lower by at least one digit than in the case of using the high frequency. This is because microwaves can generate high-density plasma as compared with high frequencies. Further, the plasma coil 62 is formed by using the electromagnetic coil 69.
As in the case of the parallel plate type plasma processing apparatus 51, the plasma generation state is maintained at a lower gas pressure or the plasma is generated at the same gas pressure by using the magnetic field 70 formed in the microwave traveling direction in the inside. The density can be increased. Further, when the frequency of the microwave is f and the magnetic flux density of the magnetic field 70 is B, B = 2πmf
/ E (e / m: specific charge, π: circular constant) a combination of a frequency and a magnetic flux density satisfying an electron cyclotron resonance (ECR) condition (for example, when the frequency is 2.45 GHz, the magnetic flux density is 8.75). If x10 ^-2 T) is used, the absorption of microwave energy by the electron system in the plasma is rapidly increased and the electron energy is increased, so that the plasma density can be further increased. Therefore, in the microwave-excited plasma processing apparatus 61, the plasma generation state can be easily maintained even if the O ₂ gas pressure introduced into the plasma generation chamber 62 is lowered to the order of 10 ⁻² Pa.

Oxygen active particles in the plasma reach the surface of the substrate 67 installed on the substrate holder 64 by diffusion, and SiH ₄ introduced from the second reactive gas introduction pipe 68 is introduced onto the surface of the substrate 67 or in the vicinity thereof. A SiO ₂ film is formed by chemically reacting with the gas. Here, when the magnetic field 70 is also used for generating plasma, the oxygen active particles are transported to the surface of the substrate 67 not only by diffusion but also by the effect of the divergent magnetic field in the plasma processing chamber 63. Further, an ion acceleration grid electrode 71 is provided, the plasma generation chamber 62 and the plasma processing chamber 63 are electrically separated, and a DC bias 72 is applied between them to positively transport the ions in the oxygen active particles. It is also possible to control the speed.

In the microwave-excited plasma processing apparatus 61, the plasma generation region and the substrate (sample) installation position are farther from each other than in the parallel plate type plasma processing apparatus 51, so that the activity with more directivity is obtained. A particle beam will inevitably be used. Therefore, in order to weaken the influence of the directional beam and form a film with good step coverage,
A substrate 67 (sample) using a high frequency bias power supply 74 connected to the substrate holder 64 via a matching circuit 73.
In some cases, a high frequency bias is applied to.

When the microwave-excited plasma processing apparatus 61 is used as a RIBE apparatus, a reactive gas introducing pipe 66 is used.
The etching gas is introduced from the above and plasma is generated by the microwave having a frequency of 2.45 GHz input from the waveguide 65. At this time, the magnetic field 70 may be used together as in the case of using the PCVD apparatus. As an etching gas, chlorine gas is used for semiconductors such as silicon and gallium arsenide, fluorine gas is used for silicon oxide film and nitride film, and oxygen gas is used for carbon polymer resist. The gas pressure is set in the range of 1 to 10 ^-2 Pa, for example. The active particles in the plasma reach the surface of the substrate 67 by the same transport mechanism as that used in the PCVD device, and etching is performed. However, when etching is performed using the RIBE device, the plasma generation chamber 62
DC bias 7 applied between the plasma processing chamber 63 and the plasma processing chamber 63
It is customary to use 2 to positively control the ion transport rate.

Since the basic etching mechanism of RIBE uses both physical sputtering by accelerated ions and chemical etching by active particles, the effect of physical sputtering by accelerated ions makes it possible to compare with the case of only chemical etching. It enables anisotropic etching such as vertical etching. In this respect, RIBE is similar to RIE. However, compared with RIE, the direct current bias 72 can control the acceleration of ions independently of other process conditions, and since plasma can be generated at a lower gas pressure, an active particle beam with high directivity can be used. The feature of RIBE is that it can be done.

[0017]

The parallel plate type plasma processing apparatus 51 can easily meet the demand for a larger area of the substrate by increasing the size of the parallel plate electrodes. Substrate (eg 400 × 500
mm ² or higher) are widely used in the manufacture of a liquid crystal display device or a semiconductor integrated circuit device using. Further, since the apparatus having basically the same configuration can be widely used for plasma processing such as PCVD, sputtering film formation, RIE, surface cleaning and resist removal, the apparatus manufacturing cost can be reduced and the vacuum can be obtained. It is easy to build an integrated device production line.

However, in the parallel plate type plasma processing apparatus 51, in forming a thin film such as an amorphous (or polycrystalline) silicon thin film or a gate oxide film, densification of plasma is limited to improve film quality and throughput. Or, there arises a problem that the reduction of the operating gas pressure for utilizing the highly directional active particle beam, which is important in anisotropic etching, is limited. From the viewpoint of gas pressure, the lower limit of the gas pressure at which plasma can be generated is usually about a dozen Pa, and the plasma generation state can be maintained at several Pa.
Up to a table (however, it can be reduced by a fraction of one to one digit when used together with a magnetic field).

Further, in the plasma treatment, the effect of irradiation ions is used while preventing the ion irradiation damage to the surface of the thin film to form a dense and good thin film, or
It is required to perform fine and precise control of the etch surface morphology and etching profile during anisotropic etching. For this reason, it is particularly important to control the transport rate of accelerated ions, but in the parallel plate plasma processing apparatus 51, a voltage drop due to self-bias is inevitably generated on the substrate (sample) installation electrode, and the voltage drop is Since it is also a function of input high-frequency power, reactive gas species and pressure (in other words, plasma density), it is difficult to completely control it independently. Therefore, there is a problem that the transport speed of accelerated ions cannot be controlled sufficiently.

On the other hand, in the microwave-excited plasma processing apparatus 61, the lower limit of the gas pressure capable of maintaining the plasma generation state can be set lower than that of the parallel plate type plasma processing apparatus 51 by at least one digit. Normally, the gas pressure is 10
It is possible to easily maintain the plasma generation state even at a low level of ^-2 Pa. Further, there is no problem caused by a voltage drop due to self-bias, and the acceleration of ions can be controlled independently of other process conditions by a DC bias applied from the outside.

However, in the microwave-excited plasma processing apparatus 61, since the plasma generation region and the substrate (sample) installation position are apart from each other, it is inevitable that a more directional active particle beam is used. . Therefore, in the case of forming a thin film on a fine uneven substrate, it is necessary to apply a high frequency bias to the substrate in order to weaken the influence of the directional beam and form a film with good step coverage. Therefore, the microwave-excited plasma processing apparatus 61
However, there is a problem in that a means for applying a high frequency bias must be newly provided.

An even more important problem is that the microwave excited plasma processing apparatus 61 cannot sufficiently handle a large area substrate. This is because the active particles containing ions in the plasma generation chamber have to be transported to a substrate at a distance, so that the active particles keep a uniform and uniform density distribution in the cross section as the active particle beam cross section increases. Because it will be difficult. In plasma generation under ECR conditions, the generated plasma is agglomerated due to concentration of magnetic field density, and it becomes more difficult to obtain a large-area active particle beam. For example, in this case, the substrate size that can be easily accommodated by the beam diameter is about 100 mm at the maximum,
It is difficult to support a rectangular substrate of 400 × 500 mm ² or more.

In addition, in the microwave excited plasma processing apparatus 61, the apparatus size in the active particle transport direction is
Inevitably, there is a problem that the size becomes larger than that of the parallel plate type plasma processing apparatus 51.

Further, in Japanese Patent Laid-Open No. 64-2321,
A plasma etching apparatus having means for applying a microwave to an etching gas between parallel plate electrodes has been disclosed for the purpose of high-speed etching without damaging the object to be processed. This plasma etching apparatus has the following problems.

In order to generate plasma, it is essential to use not only microwave but also high frequency electric field and confining magnetic field. The magnetic field distribution spreads throughout the vacuum container and becomes non-uniform between the parallel plate electrodes. This is because a magnetic field is applied using a pair of coils arranged outside the vacuum container. Therefore, it becomes difficult to obtain a uniform plasma distribution between the parallel plate electrodes, which is not suitable for etching a large area substrate. Since the microwave is introduced by connecting the waveguide to the side surface of the vacuum container, the microwave diffuses throughout the vacuum container. Therefore, plasma cannot be efficiently generated between the parallel plate electrodes. Furthermore, since the etching gas is introduced into the quartz tube of the vacuum container, the etching gas also diffuses throughout the vacuum container. No consideration is given to the gas exhaust position required to make the plasma distribution more uniform between the parallel plate electrodes.

As described above, this plasma etching apparatus cannot sufficiently cope with a large area substrate. Further, it cannot be widely used for plasma treatment such as PCVD, sputter film formation or surface treatment.

The present invention has been made to solve the above problems, and an object thereof is to enable high quality thin film formation, etching and surface treatment on a large area substrate,
It is an object of the present invention to provide a plasma processing method and a plasma processing apparatus for realizing the manufacture of a large-area or multi-chambered liquid crystal display panel and the manufacture of a high-throughput and high-yield liquid crystal display device, a semiconductor integrated circuit device, and the like.

[0028]

In order to solve the above-mentioned problems, the plasma processing method according to the invention of claim 1 has a substrate or the like on one flat plate surface of a pair of parallel flat plates which are parallel to each other in a vacuum container. In the plasma processing method, in which the object to be processed is installed and the gas is introduced between the parallel plates, the plasma is applied to the gas to be plasma-processed. It is characterized by using waves.

According to the above method, the gas introduced between the pair of parallel plates is made into plasma by using the microwaves directly introduced between the parallel plates. Therefore, a uniform and uniform plasma density distribution can be easily obtained in the area surrounded by the parallel plates. As a result, when the object to be processed is a substrate, uniform plasma processing can be performed over the entire substrate surface installed on one flat plate surface, and by increasing the size of the parallel flat plate, it is easy to request a large area of the substrate. Can correspond to. Further, basically, the plasma can be generated only by the microwave, and when the direct current bias and the high frequency bias are not required, the pair of parallel plates need not be composed of the metal electrodes.

Further, as compared with the case of using the conventional microwave-excited plasma processing apparatus, the apparatus size in the direction of transporting active particles can be reduced, and a high frequency bias is always applied to the substrate when forming a thin film on a fine uneven substrate. No need to apply.

On the other hand, since the microwave is used for plasma generation, the lower limit of the gas pressure at which the plasma generation state can be maintained is set to be lower by at least about one digit as compared with the case of using the conventional parallel plate type plasma processing apparatus. it can. In other words, the generation of high-density plasma or the reduction of the working gas pressure can be achieved as well as or more than when using the conventional microwave-excited plasma processing apparatus.

The self-bias generation mechanism that occurs when using the conventional parallel plate type plasma processing apparatus can be explained as follows. When plasma consisting mainly of positive ions and electrons is generated by a high frequency (for example, 13.56 MHz) injected between parallel plate electrodes, electrons with a small mass follow the change in polarity of the inter-electrode voltage at the frequency. However, positive ions having a large mass cannot follow the above-mentioned change in polarity. As a result, electrons are more likely to be trapped on the surface of the electrode, and a positive ion-excessive sheath region lacking electrons (that is, a non-light emitting region) is formed near the surface.
In the sheath region, a voltage drop from the region to the electrode surface, in other words, a voltage drop due to self-bias occurs. Then, the positive ions are transported to the electrode surface due to the voltage drop.

However, in the plasma processing method of the present invention, by using the microwave in the frequency region much higher than the high frequency, there is a difference in the degree of being able to follow the fluctuation of the voltage polarity generated between the positive ions and the electrons. Since the number is reduced, a voltage drop due to self-bias does not occur, and independent control of the accelerated ion transport rate can be easily performed.

In order to solve the above-mentioned problems, a plasma processing method according to a second aspect of the present invention is, in addition to the method of the first aspect, a microwave introduction region when the gas is made into plasma by the microwave. It is characterized by the combined use of magnetic fields distributed in.

According to the above method, the rotational motion component is added to the electrons in the plasma that cross the magnetic field due to the presence of the magnetic field, so that the probability of collision with neutral atoms or ions increases.

In order to solve the above-mentioned problems, a plasma processing method according to a third aspect of the present invention is, in addition to the method of the second aspect, that the frequency of the microwave is f and the magnetic flux density of the magnetic field is B. , B = 2πmf / e (e / m: specific charge, π: circular constant), electron cyclotron resonance (EC
R) It is characterized by using a combination of a frequency and a magnetic flux density that satisfy the condition.

According to the above method, the absorption of microwave energy by the electron system in the plasma is sharply increased and the electron energy is increased.

In order to solve the above problems, a plasma processing method according to a fourth aspect of the present invention is applied between the parallel plates during the plasma processing in addition to the methods of the first to third aspects. It is characterized by using DC bias together.

According to the above method, the ion transport rate can be controlled independently of other process conditions.

In order to solve the above-mentioned problems, a plasma processing method according to a fifth aspect of the present invention, in addition to the methods of the first to fourth aspects, is applied between the parallel plates during the plasma processing. It is characterized by using a high frequency bias together.

According to the above method, since the high frequency wave uniformly applied to the entire flat plate surface and the microwave which is the main plasma generating means are used together, the plasma is evenly distributed in the plane parallel to the pair of parallel flat plates. You can improve your sex.

In order to solve the above problems, a plasma processing method according to a sixth aspect of the present invention is, in addition to the methods of the first to fifth aspects, wherein a grid plate is provided between the parallel flat plates. Is provided so as to be substantially parallel to the parallel plate surface,
The microwave is directly injected between the grid plate and one or the other of the parallel plates.

According to the above method, the microwaves are efficiently confined between the one or the other flat plate and the grid plate.

In order to solve the above-mentioned problems, a plasma processing method according to a seventh aspect of the present invention is characterized in that a microwave having a frequency of 1 GHz or higher is used in addition to the methods of the first to sixth aspects. .

According to the above method, since microwaves having a high frequency of 1 GHz or more are used for plasma generation, a voltage drop due to self-bias is prevented, and at the same time a high density plasma is generated or the operating gas pressure is reduced. be able to.

In order to solve the above-mentioned problems, a plasma processing apparatus according to an eighth aspect of the present invention includes a vacuum container and a pair of parallel flat plates provided in the vacuum container and parallel to each other.
It is characterized in that a gas introducing means for introducing a gas between the parallel plates and a microwave introducing means for directly introducing a microwave between the parallel plates are provided.

According to the above construction, the gas introduced between the pair of parallel plates is turned into plasma by the microwaves directly introduced between the parallel plates. Therefore, a uniform and uniform plasma density distribution can be easily obtained in the area surrounded by the parallel plates. As a result, when the object to be processed is a substrate, uniform plasma processing can be performed over the entire substrate surface installed on one flat plate surface, and by increasing the size of the parallel flat plate, it is easy to request a large area of the substrate. Can correspond to. Further, basically, the plasma can be generated only by the microwave, and when the direct current bias and the high frequency bias are not required, the pair of parallel plates need not be composed of the metal electrodes.

Further, as compared with the conventional microwave-excited plasma processing apparatus, the apparatus size in the active particle transporting direction can be made smaller, and it is necessary to apply a high frequency bias to the substrate when forming a thin film on a fine uneven substrate. There is no. Further, generation of high-density plasma or reduction of operating gas pressure can be achieved as well as or higher than that of the conventional microwave-excited plasma processing apparatus.

In addition, by using a microwave in a frequency region much higher than that of a high frequency, the difference in the degree of being able to follow the change in the voltage polarity generated between the positive ions and the electrons is reduced, so that the self bias is applied. No voltage drop occurs, and independent control of the transport speed of accelerated ions can be easily performed.

In order to solve the above-mentioned problems, a plasma processing apparatus according to a ninth aspect of the present invention is, in addition to the configuration of the eighth aspect, the parallel plate for distributing a magnetic field in the microwave input region. It is characterized in that a plurality of magnets are arranged in the vicinity of one flat plate surface.

According to the above construction, the rotational motion component is added to the electrons in the plasma that cross the magnetic field due to the presence of the magnetic field, so that the probability of collision with neutral atoms or ions is increased.

In order to solve the above-mentioned problems, a plasma processing apparatus according to a tenth aspect of the present invention, in addition to the configuration of the eighth or ninth aspect, applies a DC bias for applying a DC bias between the parallel plates. It is characterized in that means are provided.

With the above arrangement, the ion transport rate can be controlled independently of other process conditions.

In order to solve the above-mentioned problems, the plasma processing apparatus according to the invention of claim 11 is, in addition to the structure of claims 8-10, a high-frequency bias application for applying a high-frequency bias between the parallel plates. It is characterized in that means are provided.

According to the above structure, since the high frequency wave uniformly applied to the entire flat plate surface and the microwave which is the main plasma generating means are used together, the plasma is evenly distributed in the plane parallel to the pair of parallel flat plates. You can improve your sex.

In order to solve the above-mentioned problems, a plasma processing apparatus according to a twelfth aspect of the present invention, in addition to the constitutions of the eighth to eleventh aspects, has a grid plate between the parallel flat plates. A surface is provided so as to be substantially parallel to the parallel flat plate surface, and the microwave introduction means is provided so as to directly input the microwave between one or the other flat plate of the parallel flat plate and the grid plate. It is characterized by being.

According to the above structure, the microwaves are efficiently confined between the one or the other flat plate and the grid plate.

In order to solve the above-mentioned problems, a plasma processing apparatus according to a thirteenth aspect of the present invention, in addition to the constitutions of the eighth to twelfth aspects, has a frequency of the microwave input by the microwave input means. It is characterized by being 1 GHz or more.

According to the above structure, since microwaves having a high frequency of 1 GHz or higher are used for plasma generation, a voltage drop due to self-bias is prevented from occurring, and high density plasma is generated or operating gas pressure is reduced. be able to.

[0060]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] The following will describe one embodiment of the present invention in reference to Figs.

FIG. 1 shows a plasma processing apparatus 1 according to this embodiment.
FIG. The plasma processing apparatus 1 includes a vacuum container 2, a pair of parallel flat plates 3a and 3b that are parallel to each other, and a pair of microwave waveguides 4a and 4 as microwave input means that directly inputs microwaves between the parallel flat plates 3a and 3b.
b, a reactive gas introducing passage 5 as a gas introducing means for introducing a reactive gas from the inside of the flat plate 3b between the parallel flat plates 3a and 3b, and is arranged on the back surface side of the flat plate 3b (the upper surface side of the flat plate 3b in the figure). A magnet group 6, a DC bias power source 7, a switch 8 and a gas exhaust port 9 arranged immediately below the central portion of the vacuum container 2.

In the plasma processing apparatus 1, it is not necessary to apply a high frequency for generating plasma between the pair of parallel plates 3a and 3b. Therefore, if no DC bias is applied or there is no problem caused by charge-up due to electric charges, the flat plates 3a and 3b do not have to be formed of metal electrodes. In this case, the range of selection of the constituent materials of the flat plates 3a and 3b is widened.

Basically, the microwave may be input from one direction, but in the plasma processing apparatus 1, a more uniform microwave distribution (in other words, uniform plasma distribution) is applied to the flat plate 3.
b a pair of microwave waveguides 4a for obtaining near the surface
・ 4b is provided. Microwave waveguides 4a and 4b
Have rectangular tube openings facing each other and each having a lateral width similar to the length of one side of the flat plate 3b (see, for example, FIG. 2). Further, in the plasma processing apparatus 1, since the reactive gas is introduced from the inside of the flat plate 3b by the reactive gas introduction passage 5, it is preferable that the microwave feeding position be as close to the surface of the flat plate 3b as possible. Thereby, the introduced reactive gas can be efficiently turned into plasma before being diffused in all directions.

Gas exhaust is performed from directly below the central portion of the vacuum container 2 through the gas exhaust port 9. With this configuration, the distribution of the reactive gas (in other words, plasma) can be made uniform in the horizontal plane of the vacuum container 2.

The input microwave frequency is preferably as high as 1 GHz or higher.
This can prevent the occurrence of voltage drop due to self-bias. Further, it is possible to increase the plasma generation efficiency (in other words, plasma density) and lower the operating gas pressure. For example, by using a microwave having a frequency of 2.45 GHz widely used in industry, it is possible to reduce the cost of the microwave power supply and meet the above-mentioned request for using a high frequency.

2 and 3 are perspective views showing modified examples of the configuration of the plasma processing apparatus 1. In the plasma processing apparatus 1, the reactive gas is introduced from the inside of the flat plate 3b by the reactive gas introducing passage 5, but as shown in FIGS. 2 and 3, the reaction is performed from the direction parallel to the parallel flat plate surface. A configuration in which a volatile gas is introduced may be used. In this configuration, in order to efficiently turn the reactive gas into plasma, it is preferable that the reactive gas introduction position is aligned with the microwave introduction position in the vertical direction as much as possible. Further, in order to form a uniform flow of the reactive gas, it is preferable that the gas is exhausted horizontally. Further, in this configuration, instead of the flat plate 3b, a flat plate 3c without a reactive gas introducing means may be used as shown in FIGS. The flat plates 3a, 3b, and 3c are formed in a square shape, for example, when viewed in a plan view.

The magnet group 6 used when the plasma treatment is performed in combination with the magnetic field is, for example, a magnet group 6a arranged in a line as shown in FIG. 2 or a dot matrix shape as shown in FIG. It is preferable that the number of magnets is set to be as large as possible by using the magnet group 6b arranged in the. This is to increase the plasma density or reduce the operating gas pressure while maintaining the uniformity of the plasma distribution between the parallel plates 3a and 3b (or 3a and 3c). When the line-shaped magnet group 6a is used, its arraying direction is preferably perpendicular to the microwave input direction as shown in FIG.
This is to increase the magnetic field component that coincides with the microwave input direction, and is particularly important when performing plasma processing under the electron cyclotron resonance (ECR) condition that requires a magnetic field of the microwave input direction component. Also, the magnet group 6a
6b may be a permanent magnet or an electromagnet as long as the desired magnetic field strength and magnetic flux density are obtained. When the frequency of the microwave is f and the magnetic flux density of the magnetic field is B, B = 2
ECR of πmf / e (e / m: specific charge, π: circular constant)
If a combination of the frequency and the magnetic flux density that satisfy the condition is used, the absorption of microwave energy by the electron system in the plasma is rapidly increased and the electron energy is increased.
The plasma density can be further increased. For example, when the input microwave frequency is 2.45 GHz, plasma processing can be performed under the ECR condition if a magnetic field having a magnetic flux density of 8.75 × 10 ^-2 T can be generated.

Referring to FIG. 1, in the plasma processing apparatus 1, when it is desired to further increase the directivity of the active particles irradiated on the substrate 10 placed on the flat plate 3a, the operating gas pressure is reduced and the direct current is reduced. A bias power source 7 is used to apply a DC bias between the flat plate 3a and the flat plate 3b as a cathode and the flat plate 3b as an anode. At this time, the vacuum container 2 is electrically grounded, and the flat plate 3a is grounded or floated by the switch 8. In the modified example shown in FIGS. 2 and 3, a DC bias power source 7 is used to apply a DC bias between the flat plate 3a and the flat plate 3c as the cathode and the flat plate 3c, respectively.

Using the plasma processing apparatus 1 having the above structure, plasma processing such as PCVD, sputtering film formation, etching, surface cleaning and resist removal can be performed. Hereinafter, using the plasma processing apparatus 1, a PC
A plasma processing method when performing VD, sputtering film formation and etching will be described.

First, the substrate 1 is formed by using the plasma processing apparatus 1.
A plasma processing method in the case of forming a SiO ₂ film on O will be described. Using a mixed gas of SiH ₄ and N ₂ O as a reactive gas, the mixing ratio is SiH ₄ : N ₂ O =
The state of the N ₂ O-rich as such 1:15 after evacuating the vacuum vessel 2 to a high vacuum (e.g., a back pressure of 10 ^-4 or less Pa range), introducing said reactive gas through the reactive gas introducing passage 5 To do. The gas pressure in the vacuum container 2 is kept constant (for example, 100% by controlling the intake speed and exhaust speed of the introduced gas).
Pa) and microwaves of the same power (for example, 2.45 GHz) through the pair of microwave waveguides 4a and 4b.
To generate plasma. The same power is used
This is from the viewpoint of making the plasma distribution uniform. Since microwaves with high plasma generation efficiency are used, when the plasma density is the same as when high frequency (for example, 13.56 MHz) with the same input power is used, the gas pressure should be one digit or more ( For example, it may be lowered to 10 Pa or less). On the other hand, when the gas pressure is constant, the plasma density may increase by one digit or more. Active particles such as ions in the generated plasma reach the surface of the substrate 10 by diffusing and riding on the exhaust gas flow, and the active particles of silicon and oxygen chemically react with each other on the surface of the substrate 10 or in the vicinity of the surface to form SiO 2. _Two films are formed.

When the magnetic field from the magnet group 6 is used together, the arrangement of the magnet group 6 and the magnetic field strength are adjusted in order to increase the plasma generation efficiency, so that the horizontal component of the magnetic field is input in the vertical direction. The distribution should be as close as possible to the position. This is especially important during plasma generation under ECR conditions. Further, in the plasma processing apparatus 1, by using the linear array magnet group 6a as shown in FIG. 2 or the dot matrix array magnet group 6b as shown in FIG. 3, a uniform magnetic field distribution can be obtained in the parallel plate in-plane direction. To be Therefore, the problem that occurs during plasma processing under the conventional ECR conditions, that is, the problem that it is difficult to deal with a large-area substrate due to the agglomeration of generated plasma due to concentration of magnetic field density does not occur.

When performing the sputter film formation by the plasma processing apparatus 1, instead of the flat plate 3b, as in the modification shown in FIGS. 2 and 3, the flat plate 3 having no reactive gas introducing means is used.
c, and an inert gas such as Ar is introduced from a direction parallel to the planes of the parallel plates 3a and 3c. In the sputtering film formation, first, the target is placed on the flat plate 3a which is the cathode, and the substrate is placed on the flat plate 3c. Then, the inert gas is introduced. The acceleration of the sputtering ions onto the target is performed by applying a desired bias between the parallel plates 3a and 3c using the DC bias power supply 7. In this embodiment, unlike the conventional parallel plate type plasma processing apparatus, there is no problem caused by a voltage drop due to self-bias, so that the transport rate of sputtering ions can be independently controlled.

When etching is performed by the plasma processing apparatus 1, the substrate 10 is placed on the flat plate 3a. The introduction of the reactive gas may be performed by the reactive gas introduction passage 5 or may be performed as in a modified example. The acceleration of the ions onto the target is performed by using the DC bias power source 7 in the same manner as in the above-mentioned sputtering film formation.
It is performed by applying a desired bias between a and 3c). In the etching according to the present embodiment, the acceleration of ions can be controlled independently of other process conditions as compared with the conventional RIE. Furthermore, since it is possible to generate plasma at a lower gas pressure, a highly directed active particle beam can be used.

As described above, in the plasma processing apparatus 1 of the present embodiment, the gas introduced between the pair of parallel flat plates 3a and 3b is turned into plasma by using the microwave directly injected between the parallel flat plates 3a and 3b. ing. Therefore, the parallel plate 3
A homogeneous and uniform plasma density distribution can be easily obtained in the area surrounded by a and 3b. As a result, it is possible to perform a uniform plasma treatment over the entire surface of the substrate 10 placed on the surface of one flat plate 3a, and it is possible to easily meet the demand for a larger area of the substrate 10 by increasing the size of the parallel flat plates 3a and 3b. can do. Further, as compared with the conventional microwave-excited plasma processing apparatus, the apparatus size in the active particle transport direction can be reduced, and it is not always necessary to apply a high frequency bias to the substrate 10 when forming a thin film on a fine uneven substrate. .

Furthermore, the generation of high-density plasma or the reduction of the operating gas pressure can be achieved as well as or more than the conventional microwave excitation type plasma processing apparatus.

Further, by using the microwave in the frequency region much higher than the high frequency, the difference in the degree of being able to follow the fluctuation of the voltage polarity generated between the positive ions and the electrons is reduced, so that the voltage due to the self-bias is reduced. No drop occurs, and independent control of the transport speed of accelerated ions can be easily performed.

In addition, when introducing the plasma processing apparatus 1 and the plasma processing method using the plasma processing apparatus 1 into a device production line, it is not necessary to newly develop a complicated manufacturing process, and the conventional plasma processing is performed. Replacement with the apparatus and the plasma processing method can be easily performed.

[Second Embodiment] The following will describe another embodiment of the present invention in reference to FIG.
For convenience of explanation, members having the same functions as those of the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the plasma processing apparatus 11 of the present embodiment, as shown in FIG. 4, the vacuum container 2 and the flat plate 3b as the anode are grounded, and a DC bias is applied between the flat plate 3a and the flat plate 3b. It is configured. With this configuration, in the plasma processing apparatus 11, the spread of the ion beam transported toward the flat plate 3a is smaller than that in the plasma processing apparatus 1, and the ion beam is irradiated as though it is focused on the surface of the flat plate 3a. . Therefore, when it is desired to further increase the ion density and directivity in the vicinity of the surface of the flat plate 3a, the configuration of the plasma processing apparatus 11 is suitable.

When the direct current bias circuit configuration of the plasma processing apparatus 11 is used to increase the directivity and the transport speed of the active particles, the magnet group 6 is placed on the back surface side of the flat plate 3a (in the figure,
It is preferable to install it on the lower surface side of the flat plate 3a) and distribute the magnetic field near the surface of the flat plate 3a. This is because the magnetic field distributed near the surface of the flat plate 3a traps electrons,
This is because the potential near the surface a decreases and the acceleration of ions toward the flat plate 3a is promoted.

The plasma processing apparatus 1 having the above structure
A method of performing plasma processing such as PCVD, sputter film formation, etching, surface cleaning, and resist removal using 1 is basically the same as the plasma processing method by the plasma processing apparatus 1.

Further, similar to the plasma processing apparatus 1,
Among the components of the plasma processing apparatus 11, instead of the flat plate 3b, a flat plate 3c having no reactive gas introducing means is provided as in the modification shown in FIGS. 2 and 3, and the parallel flat plates 3a.
The reactive gas may be introduced from a direction parallel to the c-plane.

[Third Embodiment] The following description will explain still another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those of the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the plasma processing apparatus 12 of this embodiment, as shown in FIG. 5, in addition to the DC bias power supply 7 in the configuration of the plasma processing apparatus 11, a high frequency bias power supply 14 is connected to the flat plate 3a via a matching circuit 13. It is configured to. The vacuum container 2 and the flat plate 3b are electrically grounded. With this configuration, in the plasma processing apparatus 12, since the high frequency that is uniformly applied to the entire flat plate surface and the microwave that is the main plasma generating means are used together, the uniformity of the plasma can be improved in the horizontal plane. Further, when the charge-up due to electric charges on the substrate 10 becomes a problem, it is possible to add a voltage drop due to the self-bias of the high frequency bias instead of reducing the ratio of the DC bias application.

When high frequency is used as the main plasma generating means, the voltage drop is, as described above, the input high frequency power,
Since it is also a function of the reactive gas species and pressure (in other words, plasma density), it is difficult to completely control it. However, in the plasma processing apparatus 12, since microwave excitation is the main plasma generating means and this is used in combination with the high frequency bias and the direct current bias, the degree of freedom in setting process parameters is high. Therefore, it is possible to sufficiently control the voltage drop.

A method of performing plasma processing such as PCVD, sputtering film formation, etching, surface cleaning and resist removal using the plasma processing apparatus 12 having the above-described structure is basically the same as the plasma processing method by the plasma processing apparatus 1. It is the same.

The plasma processing apparatus 12 has the high-frequency bias power source 14 in addition to the direct-current bias power source 7, but the present invention is not limited to this, and the high-frequency bias power source 14 may replace the direct-current bias power source 7. Good. In this case as well, the microwave, which is the main means for generating plasma, and the high-frequency bias power source 14 are used together, so that the degree of freedom in setting process parameters is high, so that the voltage drop can be sufficiently controlled.

Further, similar to the plasma processing apparatus 1,
Of the components of the plasma processing apparatus 12, instead of the flat plate 3b, a flat plate 3c having no reactive gas introducing means is provided as in the modification shown in FIGS. 2 and 3, and the parallel flat plates 3a.
The reactive gas may be introduced from a direction parallel to the c-plane.

Further, the plasma processing apparatus 12 is the DC bias power source 7 in the configuration of the plasma processing apparatus 11.
In addition to the configuration in which the high frequency bias power supply 14 and the matching circuit 13 are provided, the present invention is not limited to this. The DC bias power supply 7 in the configuration of the plasma processing apparatus 1
In addition, the high frequency bias power source 14 and the matching circuit 13 may be provided, or the direct current bias power source 7 in the configuration of the plasma processing apparatus 1 may be replaced with the high frequency bias power source 14.

[Fourth Embodiment] The following description will explain still another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those of the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 6, the plasma processing apparatus 15 of this embodiment has a structure in which, in addition to the structure of the plasma processing apparatus 1, a metal grid plate 16 is provided between a pair of parallel flat plates 3a and 3b.
Is provided. The grid plate 16 is installed so that its flat plate surface is parallel to the parallel flat plates 3a and 3b.
The introduction of the microwave and the introduction of the reactive gas are performed between the grid plate 16 and the flat plate 3b. As a result, the microwaves are efficiently confined between the grid plate 16 and the flat plate 3b, so that it is possible to generate more dense and uniform plasma between the flat plates 16 and 3b. The efficiency of confining the microwaves between the flat plates 16 and 3b is enhanced by reducing the distance between the flat plates 16 and 3b. Therefore, the grid plate 16 is preferably provided as close to the flat plate 3b as possible. Further, since the optimum distance between the flat plates 16 and 3b changes depending on the gas species, the gas pressure, etc., it is preferable that the grid plate 16 be provided so that its position in the vertical direction can be changed.

When a DC bias is also used in the plasma processing apparatus 15, the flat plate 3a is used as the cathode and the grid plate 1 is used.
Using 6 as an anode, a DC bias is applied between the both 16.3a. At this time, the flat plate 3b has the same potential as the grid plate 16, the vacuum container 2 is electrically grounded, and the flat plate 3a is grounded or floated by the switch 8.

A method of performing plasma processing such as PCVD, sputtering film formation, etching, surface cleaning and resist removal using the plasma processing apparatus 15 having the above-described structure is basically the same as the plasma processing method by the plasma processing apparatus 1. It is the same. However, in the case of sputtering film formation, the acceleration of sputtering ions onto the target is performed by applying a desired bias between the grid plate 16 and the flat plate 3a using the DC bias power supply 7. Also in the case of etching, the acceleration of the ions onto the target is performed by applying a desired bias between the grid plate 16 and the flat plate 3a using the DC bias power supply 7.

As in the case of the plasma processing apparatus 1, a reactive gas introducing means is provided instead of the flat plate 3b among the constituent elements of the plasma processing apparatus 15 as in the modified examples shown in FIGS. No flat plate 3c, parallel flat plates 3a and 3c
The reactive gas may be introduced from a direction parallel to the surface. In this case, the microwave introduction and the reactive gas introduction may be performed between the grid plate 16 and the flat plate 3c, or may be performed between the grid plate 16 and the flat plate 3a.

The plasma processing apparatus 15 may be configured to further include a high frequency bias power source 14 as shown in FIG. 5 in addition to the DC bias power source 7, or
The DC bias power source 7 may be replaced with the high frequency bias power source 14.

Further, the plasma processing apparatus 15 has a structure further including the grid plate 16 in addition to the structure of the plasma processing apparatus 1, but the present invention is not limited to this, and in addition to the structure of the plasma processing apparatuses 11 and 12, The grid plate 16 may be provided.

[0097]

As described above, the plasma processing method according to the first aspect of the present invention is a method of using the microwave directly injected between the parallel flat plates for plasmaizing the gas.

As a result, it is possible to easily cope with a large area substrate. In addition, basically, it is possible to generate plasma only by microwaves, and when the direct current bias and the high frequency bias are not required, the pair of parallel plates need not be composed of metal electrodes. The range of choice of constituent materials can be expanded.

Further, as compared with the case of using the conventional microwave-excited plasma processing apparatus, the apparatus size in the direction of transporting active particles should be reduced, and a high-frequency bias should be applied to the substrate when forming a thin film on a fine uneven substrate. It is possible to achieve the elimination of the need, and the generation of high-density plasma or the reduction of the working gas pressure to the same degree or more. In addition, a voltage drop due to self-bias does not occur, and independent control of the transport speed of accelerated ions can be easily performed.

Therefore, a high-quality thin film can be formed on a large-area substrate, etching and surface treatment can be performed, a large-area or multi-fabricated liquid crystal display panel can be manufactured, and a high-throughput and high-yield liquid crystal display device and a semiconductor integrated circuit can be manufactured. It is possible to provide a plasma processing method for realizing the manufacture of devices and the like.

As described above, in the plasma treatment method according to the invention of claim 2, in addition to the method of claim 1, when the gas is made into plasma by the microwaves, it is distributed in the microwave input region. This is a method that uses a magnetic field together.

As a result, due to the presence of the magnetic field, a rotational motion component is added to the electrons in the plasma that cross the magnetic field, increasing the probability of collision with neutral atoms or ions.

Therefore, in addition to the effect of the method of claim 1, the plasma density can be increased or the operating gas pressure can be reduced while maintaining the uniformity of the plasma distribution between the pair of parallel flat plates.

As described above, in the plasma processing method according to the invention of claim 3, in addition to the method of claim 2, when the frequency of the microwave is f and the magnetic flux density of the magnetic field is B, = 2πmf / e (e / m: specific charge, π: circular constant) is a method of using a combination of a frequency and a magnetic flux density satisfying an electron cyclotron resonance (ECR) condition.

As a result, the absorption of microwave energy by the electron system in the plasma sharply increases and the electron energy increases.

Therefore, in addition to the effect of the method according to the second aspect, it is possible to further increase the plasma density.

As described above, in the plasma processing method according to the invention of claim 4, in addition to the methods of claims 1 to 3, a DC bias applied between the parallel plates is used in combination during the plasma processing. Is the way to do it.

This allows the ion transport rate to be controlled independently of other process conditions.

Therefore, in addition to the effects of the methods according to claims 1 to 3, it is possible to easily enhance the directivity of the active particles with which the substrate is irradiated.

As described above, the plasma processing method according to the invention of claim 5 uses, in addition to the methods of claims 1 to 4, a high frequency bias applied between the parallel plates during the plasma processing. Is the way to do it.

As a result, the high frequency wave uniformly applied to the entire flat plate surface and the microwave as the main plasma generating means are used together.

Therefore, in addition to the effects of the methods of the first to fourth aspects, the uniformity of plasma can be enhanced in the plane parallel to the pair of parallel flat plates.

As described above, in the plasma processing method according to the invention of claim 6, in addition to the method of claims 1 to 5, a grid plate is provided between the parallel plates, and the plate surface of the grid plate is the parallel plate. In this method, the microwaves are provided so as to be substantially parallel to the plane, and the microwave is directly injected between one or the other of the parallel flat plates and the grid plate.

Thus, the microwaves are efficiently confined between the one or the other flat plate and the grid plate.

Therefore, in addition to the effects of the methods according to the first to fifth aspects, it is possible to generate more dense and uniform plasma between one or the other flat plate and the grid plate.

As described above, the plasma processing method according to the invention of claim 7 is a method of using microwaves having a frequency of 1 GHz or more, in addition to the methods of claims 1 to 6.

As a result, microwaves having a high frequency of 1 GHz or higher are used for plasma generation.

Therefore, in addition to the effects of the methods of claims 1 to 6, it is possible to further prevent generation of a voltage drop due to self-bias, and to generate high-density plasma or reduce operating gas pressure.

As described above, the plasma processing apparatus according to the eighth aspect of the present invention introduces the gas between the vacuum container, the pair of parallel flat plates provided in the vacuum container and parallel to each other. The gas introduction means and the microwave introduction means for directly introducing the microwave between the parallel plates.

As a result, it is possible to easily cope with a large area substrate. In addition, basically, it is possible to generate plasma only by microwaves, and when the direct current bias and the high frequency bias are not required, the pair of parallel plates need not be composed of metal electrodes. The range of choice of constituent materials can be expanded.

Further, as compared with the conventional microwave-excited plasma processing apparatus, the apparatus size in the active particle transport direction is reduced, and it is not always necessary to apply a high frequency bias to the substrate when forming a thin film on a fine uneven substrate. The generation of high-density plasma or reduction of operating gas pressure to the same or higher level,
Can be achieved. In addition, a voltage drop due to self-bias does not occur, and independent control of the transport speed of accelerated ions can be easily performed.

Therefore, it is possible to form a high quality thin film on a large-area substrate, to perform etching and surface treatment, to manufacture a large-area or multi-chambered liquid crystal display panel, and a high-throughput and high-yield liquid crystal display device and a semiconductor integrated circuit. It is possible to provide a plasma processing apparatus that realizes the manufacture of devices and the like.

As described above, in the plasma processing apparatus according to the invention of claim 9, in addition to the structure of claim 8, in order to distribute a magnetic field in the microwave input region, one of the parallel plates is In this structure, a plurality of magnets are arranged near the surface.

As a result, due to the presence of the magnetic field, a rotational motion component is added to the electrons in the plasma that cross the magnetic field, increasing the probability of collision with neutral atoms or ions.

Therefore, in addition to the effect of the structure of claim 8, the plasma density can be increased or the working gas pressure can be reduced while maintaining the uniformity of the plasma distribution between the pair of parallel flat plates.

As described above, in the plasma processing apparatus according to the invention of claim 10, in addition to the configuration of claim 8 or 9,
In this configuration, a DC bias applying means for applying a DC bias is provided between the parallel plates.

This allows the ion transport rate to be controlled independently of other process conditions.

Therefore, in addition to the effect of the structure of claim 8 or 9, it is possible to easily enhance the directivity of the active particles irradiated on the substrate.

As described above, the plasma processing apparatus according to the invention of claim 11 is provided with a high-frequency bias applying means for applying a high-frequency bias between the parallel plates in addition to the structure of claims 8-10. It has a structure.

As a result, the high frequency wave uniformly applied to the entire flat plate surface and the microwave as the main plasma generating means are used together.

Therefore, in addition to the effects of the eighth to tenth aspects, the uniformity of plasma can be enhanced in the plane parallel to the pair of parallel plates.

As described above, in the plasma processing apparatus according to the twelfth aspect of the present invention, in addition to the configurations of the eighth to eleventh aspects, the grid plates are arranged between the parallel flat plates, and the plate surfaces of the grid plates are parallel to each other. A configuration that is provided so as to be substantially parallel to a flat plate surface, and the microwave injection means is provided so as to directly input the microwave between one or the other of the parallel flat plates and the grid plate. Is.

Thereby, the microwave is efficiently confined between the one or the other flat plate and the grid plate.

Therefore, in addition to the effects of the eighth to eleventh aspects, it is possible to generate more dense and uniform plasma between one or the other flat plate and the grid plate.

As described above, in the plasma processing apparatus according to the thirteenth aspect of the present invention, in addition to the configurations of the eighth to twelfth aspects, the frequency of the microwave input by the microwave inputting means is 1 GHz or higher. It is a composition.

As a result, microwaves having a high frequency of 1 GHz or higher are used for plasma generation.

Therefore, in addition to the effects according to the eighth to twelfth aspects, it is possible to further prevent generation of a voltage drop due to self-bias and to generate high-density plasma or reduce operating gas pressure.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a modified example of the plasma processing apparatus.

FIG. 3 is a perspective view showing a modified example of the plasma processing apparatus.

FIG. 4 is a schematic configuration diagram showing a plasma processing apparatus according to another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a plasma processing apparatus according to still another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing a plasma processing apparatus according to still another embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing a conventional parallel plate type plasma processing apparatus.

FIG. 8 is a schematic configuration diagram showing a conventional microwave-excited plasma processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 2 Vacuum container 3a Flat plate 3b Flat plate 3c Flat plate 4a Microwave waveguide (microwave input means) 4b Microwave waveguide (microwave input means) 5 Reactive gas introduction path (gas introduction means) 6 Magnet group 7 DC bias power source (DC bias applying means) 8 switch 9 gas exhaust port 10 substrate 13 matching circuit 14 high frequency bias power source (high frequency bias applying means) 16 grid plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H05H 1/46 H05H 1/46 MH01L 21/302 C

Claims (13)

[Claims] 1. An object to be treated such as a substrate is placed on one flat plate surface of a pair of parallel flat plates which are parallel to each other in a vacuum container, and the object to be treated is introduced by using a gas introduced between the parallel flat plates. In the plasma processing method of performing plasma processing, a microwave directly injected between the parallel plates is used for plasma conversion of the gas. 2. The plasma processing method according to claim 1, wherein a magnetic field distributed in a microwave input region is used together when the gas is turned into plasma by the microwave. 3. When the frequency of the microwave is f and the magnetic flux density of the magnetic field is B, B = 2πmf / e (e /
The plasma processing method according to claim 2, wherein a combination of a frequency and a magnetic flux density that satisfy an electron cyclotron resonance (ECR) condition of m: specific charge and π: circular constant is used. 4. The plasma processing method according to claim 1, wherein a direct current bias applied between the parallel plates is also used during the plasma processing. 5. The plasma processing method according to claim 1, wherein a high frequency bias applied between the parallel flat plates is used together during the plasma processing. 6. A grid plate is provided between the parallel flat plates such that a plate surface of the grid plate is substantially parallel to the parallel flat plate surface, and between one or the other flat plate of the parallel flat plate and the grid plate. The plasma processing method according to any one of claims 1 to 5, wherein the microwave is directly injected into the substrate. 7. The plasma processing method according to claim 1, wherein a microwave having a frequency of 1 GHz or higher is used. 8. A vacuum vessel, a pair of parallel flat plates provided in the vacuum vessel, which are parallel to each other, a gas introducing means for introducing a gas between the parallel flat plates, and a microwave directly between the parallel flat plates. A plasma processing apparatus comprising: a microwave charging unit for charging. 9. The plasma processing according to claim 8, wherein a plurality of magnets are arranged in the vicinity of one flat plate surface of the parallel flat plate in order to distribute a magnetic field in the microwave input region. apparatus. 10. The plasma processing apparatus according to claim 8, further comprising a DC bias applying means for applying a DC bias between the parallel plates. 11. The plasma processing apparatus according to claim 8, further comprising high frequency bias applying means for applying a high frequency bias between the parallel plates. 12. A grid plate is provided between the parallel flat plates such that a plate surface of the grid plate is substantially parallel to the parallel flat plate surface, and the microwave feeding means is one or the other of the parallel flat plates. The plasma processing apparatus according to any one of claims 8 to 11, wherein the microwave is directly provided between the flat plate and the grid plate. 13. The plasma processing apparatus according to claim 8, wherein the microwave input by the microwave inputting device has a frequency of 1 GHz or higher.