JP3160194B2 - Plasma processing method and plasma processing apparatus - Google Patents

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 or a semiconductor integrated circuit device and a plasma processing apparatus for realizing the method, and more particularly, to the formation of 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 for processes such as etching, surface treatment, and the like.

[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 drive type liquid crystal display device including a thin film transistor, plasma processing is used for forming a thin film on a substrate, etching at the time of 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 an electrode, or the like on a glass substrate, a plasma enhanced chemical vapor deposition (Plasma Enhanced CVD; , PCVD) or sputter film formation. At the time of etching, reactive ion etching (Reactive Ion Etching;
Hereinafter, plasma etching such as RIE or reactive ion beam etching (hereinafter abbreviated as RIBE) is performed. Similarly, plasma processing is used in the manufacture of semiconductor integrated circuit devices, and a semiconductor substrate such as silicon or gallium arsenide is used as a substrate.

[0003] As typical plasma processing, there are two conventional techniques. In the first related art, a reactive gas is converted into plasma by a high frequency of 13.56 MHz, which is generally supplied between a pair of parallel plate electrodes, and plasma processing is performed on a substrate provided on one of the electrodes. According to the second conventional technique, a plasma generation chamber and a plasma processing chamber in which a substrate is installed are separated, and a normal 2.45 charged into the plasma generation chamber is separated.
Reactive gas is turned into plasma by microwave of GHz,
The active particles in the plasma are guided to the substrate in the plasma processing chamber by the electric field, the magnetic field, or the diffusion, and the plasma processing is performed.

[0004] The above two prior arts 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 for realizing the first conventional technique. Parallel plate type plasma processing apparatus 51
Is a vacuum vessel 52 electrically grounded, 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 Hz, a matching circuit 55 and a reactive gas introduction 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 which is electrically grounded, and the high frequency power supply 54 is connected to the electrode 53b via the matching circuit 55. As a result, the voltage drop due to the self-bias during plasma generation is smaller on the electrode 53a side than on the electrode 53b side, and the substrate surface damage due to accelerated ions is reduced to some extent. However, the voltage drop is also a function of the input high frequency power, the type of reactive gas and the pressure (in other words, the plasma density), and it is difficult to completely control the voltage drop.

The parallel plate type plasma processing apparatus 51 is connected to a PCV
A silicon dioxide (SiO ₂ ) film is formed as follows, for example, as a D device. Using a mixed gas of monosilane (SiH ₄ ) and nitrous oxide (N ₂ O) as a reactive gas, the mixture ratio is made rich in N ₂ O such as SiH ₄ : N ₂ O = 1: 15, After the inside of the vacuum vessel 52 is evacuated to a high vacuum (for example, a back pressure of 10 ⁻⁴ Pa or less), the reactive gas is introduced through a reactive gas introduction pipe 56. The gas pressure in the vacuum vessel 52 is kept constant (for example, 100 Pa) by controlling the intake speed and the exhaust speed of the gas to be introduced.
By applying a high frequency between the parallel plate electrodes 53a and 53b to generate plasma, active particles of silicon and oxygen from the plasma chemically react with each other on or near the surface of the substrate 57, thereby forming 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 tens of Pa, and the plasma generation state can be maintained only up to several Pa. A magnetic field may be used in combination 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 side of the electrode 53b,
The above object can be achieved by forming the magnetic field 59 near the surface. This is because the presence of the magnetic field 59
This is because the probability of collision with neutral atoms or ions is increased by adding a rotational motion component to the electrons in the plasma that crosses.

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 introduction pipe 56, and the target particles physically sputtered by the ions (hereinafter referred to as sputtering ions) in the inert gas plasma form the substrate. 57 can be deposited. The acceleration of the sputtering ions onto the target is performed by a voltage drop due to the self-bias on the electrode 53b side, and the voltage drop is controlled by the applied high-frequency power and the gas pressure. The voltage drop may be increased. The so-called magnetron sputter film is formed by using the magnetic field 59 from the ring-shaped magnet 58 and increasing the sputtering efficiency (in other words, the deposition rate).

The parallel plate type plasma processing apparatus 51 is RIE
When used as an apparatus, 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 introduction pipe 56,
The substrate 57 is etched using both physical sputtering using accelerated ions from etching gas plasma and chemical etching using active particles. Due to the effect of physical sputtering by accelerated ions, anisotropic etching such as vertical etching becomes possible as compared with the case of only chemical etching. The acceleration of the ions is controlled in the same manner as in the sputtering film formation. For example, in the case of plasma processing such as surface cleaning or resist removal, the acceleration voltage is suppressed as compared with the case of the anisotropic etching. Are performed. Further, a magnetic field 59 from the ring-shaped magnet 58 may be used in combination to increase the etching rate. As an etching gas, a chlorine-based gas is used for a semiconductor such as silicon or gallium arsenide, a fluorine-based gas is used for a silicon oxide film or a nitride film, and an oxygen-based gas is used for a carbon-based polymer resist.

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

The microwave-excited plasma processing apparatus 6
When forming a SiO ₂ film on the substrate 67 by using 1 as a PCVD apparatus, a second reactive gas introduction pipe 68 for introducing a reactive gas near the surface of the substrate holder 64 is further provided. 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 SiH ₄ is introduced from the gas introduction pipe 68. The O ₂ gas introduced into the plasma generation chamber 62 has a frequency of 2.45 GHz supplied from the waveguide 65.
Is converted into plasma by the microwave.

In the case of using microwaves represented by a frequency of 2.45 GHz, the lower limit of the gas pressure at which the plasma generation state can be maintained can be set at least one digit lower than in the case of using high frequencies. This is because microwaves can generate high-density plasma compared to high frequencies. Further, the plasma generating chamber 62 is
As in the case of the parallel plate type plasma processing apparatus 51, a plasma generation state is maintained at a lower gas pressure, or the plasma is generated at the same gas pressure, as in the case of the parallel plate type plasma processing apparatus 51. 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: pi) 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) When (10 ⁻² T) is used, the absorption of microwave energy by the electron system in the plasma sharply increases and the electron energy increases, so that the plasma density can be further increased. Therefore, in the microwave excitation type plasma processing apparatus 61, even if the O ₂ gas pressure introduced into the plasma generation chamber 62 is reduced to the order of 10 ⁻² Pa, the plasma generation state can be easily maintained.

The oxygen active particles in the plasma reach the surface of the substrate 67 placed on the substrate holder 64 by diffusion, and the SiH ₄ introduced from the second reactive gas introduction pipe 68 at or near the surface of the substrate 67. A chemical reaction with the gas forms an SiO ₂ film. Here, when the magnetic field 70 is used in combination with the generation of the plasma, the oxygen active particles are transported to the surface of the substrate 67 by the effect of the diverging magnetic field in the plasma processing chamber 63 in addition to the diffusion. In addition, a grid electrode 71 for ion acceleration is provided, the plasma generation chamber 62 and the plasma processing chamber 63 are electrically separated, and a DC bias 72 is applied between the two to positively transport ions in the oxygen active particles. It is also possible to control the speed.

By the way, in the microwave-excited plasma processing apparatus 61, the plasma generation region and the substrate (sample) installation position are farther apart than the parallel plate type plasma processing apparatus 51. A particle beam will inevitably be used. Therefore, in order to weaken the influence of the directional beam and perform film formation with good step coverage,
Using a high frequency bias power supply 74 connected to a substrate holder 64 via a matching circuit 73, a substrate 67 (sample)
May be applied with a high-frequency bias.

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

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 is lower than that of chemical etching alone. And anisotropic etching such as vertical etching. In this regard, RIBE is similar to RIE. However, compared to RIE, the DC bias 72 can control the acceleration of ions independently of other process conditions, and the plasma can be generated at a lower gas pressure, so that a highly directional active particle beam is used. One of the features of RIBE is that it can be used.

[0017]

The parallel plate type plasma processing apparatus 51 can easily cope with a demand for a large substrate by increasing the size of the parallel plate electrodes. Substrate (for example, 400 × 500
mm ² or more) is widely used for manufacturing liquid crystal display devices or semiconductor integrated circuit devices. Further, since the apparatus having basically the same configuration can be widely used for plasma processing such as PCVD, sputter film formation, RIE, surface cleaning and resist removal, the manufacturing cost of the apparatus can be reduced, and vacuum 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, the density of plasma for improving film quality and throughput is limited. In addition, there is a problem that the reduction of the operating gas pressure for use of a highly directional active particle beam which is important during 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 ten and several Pa, and the plasma generation state can be maintained at several Pa.
Up to the order of magnitude (however, the combined use of a magnetic field further reduces the order of magnitude by several orders of magnitude to an order of magnitude).

Further, in the plasma treatment, a dense and good-quality thin film is formed by utilizing the effect of irradiated ions while preventing ion irradiation damage to the thin film surface.
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 speed of the accelerated ions. In the parallel plate type plasma processing apparatus 51, a voltage drop due to a self-bias on the substrate (sample) installation electrode necessarily occurs, and the voltage drop is reduced. It is also a function of the input high-frequency power, the reactive gas type and the pressure (in other words, the plasma density), and so it is difficult to completely independently control the same. Therefore, there arises a problem that the transport speed of the accelerated ions cannot be sufficiently controlled.

On the other hand, in the microwave-excited plasma processing apparatus 61, the lower limit of the gas pressure at which the plasma generation state can be maintained can be set at least one order of magnitude lower than in the parallel-plate plasma processing apparatus 51. Usually, the gas pressure is 10
^The plasma generation state can be easily maintained even at a low level of ^-2 Pa. Further, there is no problem caused by a voltage drop due to the self-bias, and the acceleration of ions can be controlled independently of other process conditions by a DC bias externally applied.

However, in the microwave-excited plasma processing apparatus 61, since the plasma generation region is far from the substrate (sample) installation position, an active particle beam having more directivity is inevitably 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 arises a problem that 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 cope with a large-area substrate. Since the active particles including ions in the plasma generation chamber must be transported to a substrate at a distance, the active particles are maintained in a uniform and uniform density distribution within the cross section as the cross section of the active particle beam increases. This is because it becomes difficult. In the plasma generation under the ECR condition, the generated plasma aggregates due to the concentration of the 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 handled by the beam diameter is at most about 100 mm in diameter,
It is difficult to correspond to a rectangular substrate of 400 × 500 mm ² or more.

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

In Japanese Patent Application Laid-Open No. Sho 64-23221,
For the purpose of performing high-speed etching without damaging an object to be processed, a plasma etching apparatus provided with a means for applying a microwave to an etching gas between parallel plate electrodes has been disclosed. This plasma etching apparatus has the following problems.

For the generation of plasma, not only microwaves but also high-frequency electric fields and confining magnetic fields are indispensable. The magnetic field distribution spreads throughout the vacuum vessel 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 vessel. 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 vessel, the microwave is diffused throughout the vacuum vessel. Therefore, plasma cannot be efficiently generated between the parallel plate electrodes. Further, since the etching gas is introduced into the quartz tube of the vacuum vessel, the etching gas also diffuses throughout the vacuum vessel. 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. Furthermore, it cannot be widely used for plasma processing such as PCVD, sputter deposition or surface processing.

The present invention has been made to solve the above problems, and an object of the present invention 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 a large-area or multi-panel liquid crystal display panel, a liquid crystal display device with high throughput and a high yield, and a semiconductor integrated circuit device.

[0028]

According to a first aspect of the present invention, there is provided a plasma processing method comprising the steps of: providing a substrate or the like on one of a pair of parallel flat plates in a vacuum vessel; In the plasma processing method in which the object to be processed is installed and the object to be processed is plasma-processed by using a gas introduced between the parallel plates, the input directions between the parallel plates are opposite to each other when the gas is turned into plasma. It is characterized by the use of microwaves directly be turned to.

According to the above method, the gas introduced between the pair of parallel flat plates is opposed to each other between the parallel flat plates.
As shown in the figure, plasma is generated using microwaves directly applied. Therefore, a uniform and uniform plasma density distribution can be easily obtained in a region surrounded by the parallel flat plates. As a result, when the object to be processed is a substrate, uniform plasma processing can be performed over the entire surface of the substrate provided on one of the flat surfaces, and by increasing the size of the parallel flat plate, it is easy to request a large substrate area. Can be handled. In addition, it is basically possible to generate plasma only by microwaves, and when a DC bias and a high-frequency bias are not required, the pair of parallel flat plates need not be formed of metal electrodes.

Further, as compared with the case where a conventional microwave excitation type plasma processing apparatus is used, the apparatus size in the active particle transport direction can be reduced, and a high frequency bias is always applied to the substrate when forming a thin film on a fine uneven substrate. There is no need to apply.

On the other hand, since microwaves are used for plasma generation, the lower limit of the gas pressure at which the plasma generation state can be maintained is set at least one order of magnitude lower than when a conventional parallel plate type plasma processing apparatus is used. it can. In other words, the generation of high-density plasma or the reduction of the operating gas pressure can be achieved as compared with the case of using the conventional microwave excitation type plasma processing apparatus.

The self-bias generation mechanism that occurs when a conventional parallel plate type plasma processing apparatus is used can be explained as follows. When a plasma mainly composed of positive ions and electrons is generated by a high frequency (eg, 13.56 MHz) applied between the parallel plate electrodes, the electrons having a small mass follow the fluctuation of the polarity of the voltage between the electrodes at the frequency. However, the positive ions having a large mass cannot follow the fluctuation of the polarity. As a result, the probability that electrons are trapped on the electrode surface increases, and a sheath region (ie, a non-light-emitting region) in which electrons are lacking and in which positive ions are excessive is formed near the surface.
In the sheath region, a voltage drop from the region toward the electrode surface, in other words, a voltage drop due to self-bias occurs. Then, the positive ions are transported to the electrode surface by the voltage drop.

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

According to a second aspect of the present invention, there is provided a plasma processing method according to the first aspect of the present invention, further comprising: It is characterized by using a magnetic field distributed in the same manner.

According to the above-mentioned method, the probability of collision with neutral atoms or ions is increased by adding a rotational motion component to the electrons in the plasma crossing the magnetic field due to the presence of the magnetic field.

According to a third aspect of the present invention, there is provided a plasma processing method according to the second aspect, wherein the frequency of the microwave is f and the magnetic flux density of the magnetic field is B. When B = 2πmf / e (e / m: specific charge, π: pi), the electron cyclotron resonance (EC
R) It is characterized by using a combination of frequency and magnetic flux density that satisfies the condition.

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

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the first to third aspects, during the plasma processing, a voltage is applied between the parallel flat plates. It is characterized by using a DC bias together.

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

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

According to the above-mentioned method, since the high frequency uniformly applied to the entire flat plate surface and the microwave which is the main means for generating plasma are used together, the uniformity of the plasma within the plane parallel to the pair of parallel flat plates is obtained. Can be enhanced.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the first to fifth aspects, 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 applied between one or other of the parallel flat plates and the grid plate.

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

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

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

According to another aspect of the present invention, there is provided a plasma processing apparatus comprising: a vacuum vessel; a pair of parallel flat plates provided in the vacuum vessel;
And gas introducing means for introducing a gas between the parallel plates, is characterized in that it comprises a direct-on to luma microwave supplying device microwaves from the tube opening which faces between the parallel plates.

According to the above configuration, the gas introduced between the pair of parallel flat plates is turned into plasma by the microwaves directly injected from the tube ports facing each other between the parallel flat plates. Therefore, a uniform and uniform plasma density distribution can be easily obtained in a region surrounded by the parallel flat plates. As a result, when the object to be processed is a substrate, uniform plasma processing can be performed over the entire surface of the substrate provided on one of the flat surfaces, and by increasing the size of the parallel flat plate, it is easy to request a large substrate area. Can be handled. In addition, it is basically possible to generate plasma only by microwaves, and when a DC bias and a high-frequency bias are not required, the pair of parallel flat plates need not be formed of metal electrodes.

Further, as compared with the conventional microwave excitation type plasma processing apparatus, the apparatus size in the active particle transport direction can be reduced, and it is necessary to always apply a high frequency bias to the substrate when forming a thin film on a fine uneven substrate. There is no. In addition, generation of high-density plasma or reduction of operating gas pressure can be achieved to be equal to or higher than the conventional microwave excitation type 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 following the fluctuation of the voltage polarity generated between the positive ions and the electrons is reduced. No voltage drop occurs, and independent control of the transport speed of the accelerated ions can be easily performed.

According to a ninth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of the eighth aspect, the parallel plate is provided for distributing a magnetic field in the microwave input region. A plurality of magnets are arranged near one of the flat surfaces.

According to the above configuration, the probability of collision with neutral atoms or ions is increased by adding a rotational motion component to electrons in the plasma crossing the magnetic field due to the presence of the magnetic field.

According to a tenth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of the eighth or ninth aspect, a DC bias application for applying a DC bias between the parallel plates is provided. Means are provided.

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

According to an eleventh aspect of the present invention, in order to solve the above-mentioned problems, in addition to the constitution of the eighth to tenth aspects, a high-frequency bias application for applying a high-frequency bias between the parallel plates is provided. Means are provided.

According to the above configuration, since the high frequency uniformly applied to the entire flat plate surface and the microwave which is the main generation means of the plasma are used together, the uniformity of the plasma within the plane parallel to the pair of parallel flat plates is obtained. Can be enhanced.

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

According to the above configuration, the microwave is efficiently confined between one or the other flat plate and the grid plate.

According to a thirteenth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the constitutions of the eighth to twelfth aspects, the frequency of the microwave input by the microwave input means is increased. It is characterized by being at least 1 GHz.

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

[0060]

[Embodiment 1] One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a plasma processing apparatus 1 according to this embodiment.
FIG. The plasma processing apparatus 1 includes a vacuum vessel 2, a pair of parallel flat plates 3a and 3b parallel to each other, and a pair of microwave waveguides 4a and 4 as microwave input means for directly inputting microwaves between the parallel flat plates 3a and 3b.
b, a reactive gas introduction path 5 as a gas introduction means for introducing a reactive gas between the parallel flat plates 3a and 3b from inside the flat plate 3b, and disposed on the back side of the flat plate 3b (the upper side of the flat plate 3b in the figure). A magnet group 6, a DC bias power supply 7, a switch 8, and a gas exhaust port 9 disposed immediately below the center of the vacuum vessel 2 are provided.

In the plasma processing apparatus 1, there is no need to supply a high frequency for generating plasma between the pair of parallel flat plates 3a and 3b. Therefore, when no DC bias is applied or when there is no problem caused by charge-up due to charges, the flat plates 3a and 3b do not need to be formed of metal electrodes. In this case, the range of choice of the constituent materials of the flat plates 3a and 3b is expanded.

Although the microwave may be supplied basically from one direction, in the plasma processing apparatus 1, a more uniform microwave distribution (in other words, a uniform plasma distribution) is applied to the flat plate 3.
b, a pair of microwave waveguides 4a
4b is provided. Microwave waveguides 4a and 4b
Have rectangular pipe openings each having the same width as the length of one side of the flat plate 3b (see, for example, FIG. 2). 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 input position is as close as possible to the surface of the flat plate 3b. This makes it possible to efficiently generate plasma before the introduced reactive gas diffuses in all directions.

The gas is exhausted from just below the center of the vacuum vessel 2 through the gas exhaust port 9. With this configuration, the distribution of the reactive gas (in other words, plasma) in the horizontal plane of the vacuum vessel 2 can be made uniform.

It is preferable that the input microwave frequency be as high as possible, such as 1 GHz or more.
This can prevent a voltage drop due to self-bias. Further, it is possible to increase the plasma generation efficiency (in other words, the plasma density) and to lower the operating gas pressure. For example, if microwaves having a frequency of 2.45 GHz, which are widely used in industry, are used, the cost of the microwave power supply can be reduced and the demand for the use of the high frequency can be satisfied.

FIGS. 2 and 3 are perspective views showing modified examples of the configuration of the plasma processing apparatus 1. FIG. The plasma processing apparatus 1 has a configuration in which the reactive gas is introduced from the inside of the flat plate 3b by the reactive gas introduction passage 5, but as shown in FIGS. 2 and 3, the reactive gas is reacted from a direction parallel to the plane of the parallel flat plate. A configuration in which a reactive gas is introduced may be adopted. In this configuration, in order to efficiently convert the reactive gas into plasma, it is preferable that the reactive gas introduction position coincides 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 in a horizontal direction. Further, in this configuration, as shown in FIGS. 2 and 3, a flat plate 3c having no reactive gas introducing means may be used instead of the flat plate 3b. The flat plates 3a, 3b, 3c are formed, for example, in a square shape when viewed from a plane.

The magnet group 6 used when performing the plasma processing in combination with the magnetic field may be, for example, a magnet group 6a arranged in a line as shown in FIG. 2 or a dot matrix as shown in FIG. And the number of magnets is preferably as large as possible. This is for increasing the plasma density or reducing 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, the arrangement direction is preferably perpendicular to the microwave input direction as shown in FIG.
This is to increase the magnetic field component corresponding to the microwave input direction, and is particularly important when performing plasma processing under electron cyclotron resonance (ECR) conditions that require a magnetic field of the microwave input direction component. 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 can be obtained. When the frequency of the microwave is f and the magnetic flux density of the magnetic field is B, B = 2
ECR which is πmf / e (e / m: specific charge, π: pi)
If a combination of the frequency and the magnetic flux density that satisfies the condition is used, the absorption of microwave energy by the electron system in the plasma sharply increases, and the electron energy increases.
The plasma density can be further increased. For example, when the input microwave frequency is 2.45 GHz, if a magnetic field having a magnetic flux density of 8.75 × 10 ⁻² T can be generated, plasma processing can be performed under ECR conditions.

Referring to FIG. 1, in plasma processing apparatus 1, when it is desired to further increase the directivity of active particles irradiated on substrate 10 placed on flat plate 3a, in addition to reducing the operating gas pressure, DC Using the bias power source 7, a DC bias is applied between the plate 3a and the plate 3b using the plate 3a as a cathode and the plate 3b as an anode. At this time, the vacuum vessel 2 is electrically grounded, and the flat plate 3a is grounded or floated by the switch 8. In the modification shown in FIGS. 2 and 3, the DC bias power source 7 is used to apply a DC bias between the plates 3a and 3c using the plate 3a as a cathode and the plate 3c as an anode.

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

First, using the plasma processing apparatus 1, the substrate 1
A description will be given of a plasma processing method for forming an SiO ₂ film on the substrate 0. Using a mixed gas of SiH ₄ and N ₂ O as a reactive gas, the mixing ratio was set to 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 I do. The gas pressure in the vacuum vessel 2 is kept constant (for example, 100 V) by controlling the intake speed and the exhaust speed of the gas to be introduced.
Pa) and microwaves of the same power (for example, 2.45 GHz) through a 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 having high plasma conversion efficiency are used, when the plasma density is the same as when using the same high frequency (for example, 13.56 MHz) using the same input power, the gas pressure is increased by one digit or more ( For example, it may be reduced 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. The 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. _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 strength of the magnetic field are adjusted so as to increase the horizontal component of the magnetic field in the vertical direction. The distribution should be as coincident as possible with the position. This is especially important during plasma generation under ECR conditions. Further, in the plasma processing apparatus 1, a uniform magnetic field distribution is obtained in the in-plane direction of the parallel plate by using the linearly arranged magnet group 6a as shown in FIG. 2 or the dot matrix-like arranged magnet group 6b as shown in FIG. Can be Therefore, there is no problem that occurs in the conventional plasma processing under the ECR condition, that is, a problem that it is difficult to cope with a large-area substrate due to aggregation of generated plasma due to magnetic field density concentration.

When the sputter film is formed by the plasma processing apparatus 1, instead of the flat plate 3b, a flat plate 3 having no reactive gas introducing means as in the modification shown in FIGS. 2 and 3 is used.
c, and an inert gas such as Ar is introduced from a direction parallel to the plane of the parallel plates 3a and 3c. In the sputter deposition, first, a target is set on the flat plate 3a serving as a cathode, and a substrate is set 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, since there is no problem caused by the voltage drop due to the self-bias unlike the conventional parallel plate type plasma processing apparatus, the transport speed of the 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 path 5 or may be performed as in a modified example. The acceleration of the ions on the target is performed by using the DC bias power source 7 and the parallel plates 3a and 3b (or 3
This 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 plasma can be generated at a lower gas pressure, an active particle beam having high directivity 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 converted into plasma using the microwave directly injected between the parallel flat plates 3a and 3b. ing. Therefore, the parallel plate 3
A uniform and uniform plasma density distribution can be easily obtained in the region surrounded by a and 3b. As a result, uniform plasma processing can be performed on the entire surface of the substrate 10 placed on one flat plate 3a, and the size of the parallel flat plates 3a and 3b can be increased to easily respond to a request for a large area of the substrate 10. can do. Further, as compared with a conventional microwave excitation type plasma processing apparatus, the apparatus size in the active particle transport direction can be reduced, and it is not necessary to apply a high frequency bias to the substrate 10 when forming a thin film on a fine uneven substrate. .

Furthermore, high-density plasma can be generated or the operating gas pressure can be reduced to a level equal to or higher than that of a conventional microwave-excited plasma processing apparatus.

Further, by using a microwave in a frequency region much higher than that of a high frequency, the difference in the degree of following the fluctuation of the voltage polarity generated between the positive ions and the electrons is reduced. No descent occurs, and independent control of the transport speed of the accelerated ions can be easily performed.

In addition, in introducing the plasma processing apparatus 1 and the plasma processing method using the plasma processing apparatus 1 into a device production line, there is no need to develop a new complicated manufacturing process, and the conventional plasma processing apparatus can be used. The replacement with the apparatus and the plasma processing method can be easily performed.

[Embodiment 2] The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the plasma processing apparatus 11 of this embodiment, as shown in FIG. 4, the vacuum vessel 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 has a configuration. With this configuration, in the plasma processing apparatus 11, the spread of the ion beam transported toward the flat plate 3a is smaller than in the plasma processing apparatus 1, and the ion beam is irradiated as if it were focused on the flat plate 3a surface. . Therefore, when it is desired to increase the ion density and the directivity near the surface of the flat plate 3a, the configuration of the plasma processing apparatus 11 is suitable.

When the DC bias circuit configuration of the plasma processing apparatus 11 is used to increase the directivity and transport speed of the active particles, the magnet group 6 is moved to the back side of the flat plate 3a (in FIG.
It is preferable to dispose 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, and
This is because the potential near the surface a decreases and the acceleration of ions toward the flat plate 3a is accelerated.

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

Further, similarly 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 introduction means as in the modification shown in FIGS.
A configuration in which the reactive gas is introduced from a direction parallel to the c-plane may be employed.

Third Embodiment Still another embodiment of the present invention is described below with reference to FIG. For convenience of explanation, members having the same functions as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 5, in the plasma processing apparatus 12 of this embodiment, 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. Configuration. The vacuum vessel 2 and the flat plate 3b are electrically grounded. According to this configuration, in the plasma processing apparatus 12, since the high frequency uniformly applied to the entire flat surface and the microwave which is the main generation means of the plasma are used together, the uniformity of the plasma in the horizontal plane can be improved. Further, when charge-up due to electric charges on the substrate 10 becomes a problem, it is possible to add a voltage drop due to a self-bias of a high-frequency bias instead of reducing the rate of DC bias application.

When the high frequency is used as the main plasma generating means, the voltage drop is determined by the applied high frequency power,
Since it is also a function of the reactive gas species and the pressure (in other words, the plasma density), it is difficult to completely control them independently. However, the plasma processing apparatus 12 has a high degree of freedom in setting process parameters because microwave excitation is used as a main plasma generating means and is used in combination with a high frequency bias and a DC bias. Therefore, it is possible to sufficiently control the voltage drop.

The method of performing plasma processing such as PCVD, sputter deposition, etching, surface cleaning, and resist removal using the plasma processing apparatus 12 having the above configuration is basically the same as the plasma processing method using the plasma processing apparatus 1. The same is true.

Although the plasma processing apparatus 12 has the high frequency bias power supply 14 in addition to the DC bias power supply 7, the present invention is not limited to this. Good. Also in this case, since the microwave which is the main means for generating plasma and the high frequency bias power supply 14 are used in combination, the degree of freedom in setting the process parameters is high, so that the voltage drop can be sufficiently controlled.

Further, similarly to the plasma processing apparatus 1,
Among the components of the plasma processing apparatus 12, instead of the flat plate 3b, a flat plate 3c having no reactive gas introduction means as in the modification shown in FIGS.
A configuration in which the reactive gas is introduced from a direction parallel to the c-plane may be employed.

Further, the plasma processing apparatus 12 includes the DC bias power source 7 in the configuration of the plasma processing apparatus 11.
In addition to the configuration, the high-frequency bias power supply 14 and the matching circuit 13 are provided, but the configuration is not limited thereto.
In addition, a configuration in which a high-frequency bias power supply 14 and a matching circuit 13 are provided may be used, or a configuration in which the DC bias power supply 7 in the configuration of the plasma processing apparatus 1 is replaced with the high-frequency bias power supply 14 may be used.

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

As shown in FIG. 6, the plasma processing apparatus 15 of this embodiment has a configuration in which a metal grid plate 16 is provided between a pair of parallel flat plates 3a and 3b in addition to the configuration of the plasma processing apparatus 1.
Is provided. The grid plate 16 is installed such that its flat 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 microwave is efficiently confined between the grid plate 16 and the flat plate 3b, so that a higher density and uniform plasma can be generated between the flat plates 16 and 3b. The efficiency of confining microwaves between the flat plates 16 and 3b can be increased 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. Since the optimum distance between the flat plates 16 and 3b changes depending on the gas type, gas pressure, and the like, the grid plate 16 is preferably provided so that the position in the vertical direction can be changed.

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

The method of performing plasma processing such as PCVD, sputter deposition, etching, surface cleaning and resist removal using the plasma processing apparatus 15 having the above configuration is basically the same as the plasma processing method using the plasma processing apparatus 1. The same is true. However, in the case of performing the sputter deposition, the acceleration of the 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 performing etching, acceleration of 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 in the components of the plasma processing apparatus 15 as in the modified example shown in FIGS. No flat plate 3c, and parallel flat plates 3a and 3c
A configuration in which the reactive gas is introduced from a direction parallel to the plane may be employed. In this case, the introduction of the microwave and the introduction of the reactive gas may be performed between the grid plate 16 and the flat plate 3c, or 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 supply 14 as shown in FIG. 5 in addition to the DC bias power supply 7, or
The DC bias power supply 7 may be replaced with a high frequency bias power supply 14.

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

[0097]

As described above, the plasma processing method according to the first aspect of the present invention uses microwaves directly injected into the parallel plates so that the injection directions are opposed to each other, for the gasification of the gas. Is the way.

Thus, it is possible to easily cope with a large area substrate. Also, it is basically possible to generate plasma only by microwaves, and when a DC bias and a high frequency bias are not required, a pair of parallel plates need not be formed of metal electrodes. The range of choice of the constituent materials can be expanded.

Further, as compared with the case where a conventional microwave excitation type plasma processing apparatus is used, the apparatus size in the active particle transport direction is reduced, and a high frequency bias is always applied to the substrate when forming a thin film on a fine uneven substrate. This eliminates the necessity and achieves the generation of high-density plasma or the reduction of the operating 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, etched and surface-treated on a large-area substrate, and a large-area or multi-panel 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. A plasma processing method for realizing the manufacture of a device or the like can be provided.

According to the plasma processing method of the second aspect of the present invention, as described above, in addition to the method of the first aspect, when the gas is turned into plasma by the microwave, the gas is distributed in a microwave input region. In this method, a magnetic field is used.

Thus, the presence of the magnetic field causes a rotational motion component to be added to the electrons in the plasma crossing the magnetic field, thereby increasing the probability of collision with neutral atoms and ions.

Therefore, in addition to the effect of the method of the first aspect, 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 third aspect of the present invention, 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: pi) This method uses a combination of frequency and magnetic flux density that satisfies the 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 of the second aspect, it is possible to further increase the plasma density.

According to the plasma processing method of the present invention, the DC bias applied between the parallel plates during the plasma processing is used in addition to the methods of the first to third embodiments. How to

Thus, the transport speed of ions can be controlled independently of other process conditions.

Therefore, in addition to the effects of the first to third methods, the directivity of the active particles irradiated on the substrate can be easily increased.

The plasma processing method according to the fifth aspect of the present invention, as described above, uses the high-frequency bias applied between the parallel flat plates during the plasma processing in addition to the methods of the first to fourth aspects. How to

Thus, the high frequency uniformly applied to the entire flat plate surface and the microwave which is the main means for generating plasma are used together.

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

According to a sixth aspect of the present invention, as described above, in addition to the first to fifth aspects, a grid plate is provided between the parallel flat plates so that the surface of the grid plate is the parallel flat plate. This is a method in which the microwave is provided so as to be substantially parallel to the surface, and the microwave is directly applied between one or the other of the parallel flat plates and the grid plate.

As a result, microwaves are efficiently confined between one or the other flat plate and the grid plate.

Therefore, in addition to the effects of the first to fifth aspects, a higher-density and uniform plasma can be generated between one or the other flat plate and the grid plate.

The plasma processing method according to the invention of claim 7 is, as described above, a method of using a microwave 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 more are used for plasma.

Therefore, in addition to the effects of the first to sixth aspects, a voltage drop due to self-bias can be prevented, and high-density plasma can be generated or the operating gas pressure can be reduced.

According to the plasma processing apparatus of the present invention, as described above, a vacuum vessel, a pair of parallel flat plates provided in the vacuum vessel, and a gas introduced between the parallel flat plates. a gas introduction means, is configured to include a direct-on to luma Lee <br/> black wave supplying device microwaves from the tube opening which faces between the parallel plates.

Thus, it is possible to easily cope with a large area substrate. Also, it is basically possible to generate plasma only by microwaves, and when a DC bias and a high frequency bias are not required, a pair of parallel plates need not be formed of metal electrodes. The range of choice of the constituent materials can be expanded.

Further, as compared with a conventional microwave excitation type plasma processing apparatus, the apparatus size in the active particle transport direction can be reduced, and it is not necessary to apply a high frequency bias to the substrate when forming a thin film on a fine uneven substrate. That, to the same extent or more, to generate high-density plasma or reduce the operating gas pressure;
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 multiple-panel liquid crystal display panel, and to provide 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.

According to a ninth aspect of the present invention, as described above, in addition to the configuration of the eighth aspect, in order to distribute a magnetic field in the microwave input region, one of the parallel flat plates is used. In this configuration, a plurality of magnets are arranged near the surface.

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

Therefore, in addition to the effect of the configuration of claim 8, it is possible to increase the plasma density or reduce the operating gas pressure while maintaining the uniformity of the plasma distribution between the pair of parallel flat plates.

According to the tenth aspect of the present invention, as described above, in addition to the structure of the eighth or ninth aspect,
In this configuration, DC bias applying means for applying a DC bias between the parallel plates is provided.

Thus, the transport speed of ions can be controlled independently of other process conditions.

Therefore, in addition to the effect of the configuration of claim 8 or 9, the directivity of the active particles irradiated on the substrate can be easily enhanced.

In the plasma processing apparatus according to the eleventh aspect of the present invention, as described above, in addition to the constitutions of the eighth to tenth aspects, a high-frequency bias applying means for applying a high-frequency bias between the parallel plates is provided. Configuration.

Thus, the high frequency uniformly applied to the entire flat surface and the microwave which is the main means for generating plasma are used together.

Therefore, in addition to the effects of the constitutions of claims 8 to 10, the uniformity of plasma can be enhanced in a plane parallel to the pair of parallel flat plates.

As described above, in the plasma processing apparatus according to the twelfth aspect, in addition to the constitutions of the eighth to eleventh aspects, a grid plate is provided between the parallel flat plates, and A configuration in which the microwave input means is provided so as to be substantially parallel to a flat plate surface, and the microwave input 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.

Thus, the microwave is efficiently confined between 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 a higher-density and uniform plasma between one or the other flat plate and the grid plate.

According to a thirteenth aspect of the present invention, as described above, in addition to the configuration of the eighth to twelfth aspects, the frequency of the microwave input by the microwave input means is 1 GHz or more. Configuration.

As a result, a microwave having a high frequency of 1 GHz or more is used for plasma.

Therefore, in addition to the effects of the constitutions of claims 8 to 12, it is possible to prevent a voltage drop due to a 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 illustrating 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 excitation type 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 supply (DC bias applying means) 8 Switch 9 Gas exhaust port 10 Substrate 13 Matching circuit 14 High frequency bias power supply (High frequency bias applying means) 16 Grid plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI H05H 1/46 H05H 1/46 M H01L 21/302 C (56) References JP-A-2-83924 (JP, A) JP JP-A-7-211695 (JP, A) JP-A-2-13827 (JP, A) JP-A-5-93277 (JP, A) JP-A-5-182785 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H01L 21/31 C23C 16/50 C30B 35/00 H01L 21/205 H01L 21/3065 H05H 1/46

Claims (13)

(57) [Claims] An object to be processed such as a substrate is placed on one of a pair of parallel flat plates in a vacuum vessel, and the object is processed using a gas introduced between the parallel flat plates. In the plasma processing method of performing plasma processing, the direction of injection between the parallel plates is
A plasma processing method using microwaves directly applied so as to face each other . 2. The plasma processing method according to claim 1, wherein, when the gas is converted into plasma by the microwave, a magnetic field distributed in a microwave input region is used together. 3. When the frequency of the microwave is f and the magnetic flux density of the magnetic field is B, B = 2πmf / e (e /
3. The plasma processing method according to claim 2, wherein a combination of a frequency and a magnetic flux density that satisfies an electron cyclotron resonance (ECR) condition of m: specific charge, π: pi is used. 4. The plasma processing method according to claim 1, wherein a DC bias applied between said parallel plates is used in said plasma processing. 5. The plasma processing method according to claim 1, wherein a high-frequency bias applied between said parallel plates is used in said plasma processing. 6. A grid plate is provided between said parallel flat plates so that a plate surface of said grid plate is substantially parallel to said parallel flat plate surface, and a grid plate is provided between one or other flat plate of said parallel flat plates and said grid plate. The plasma processing method according to any one of claims 1 to 5, wherein the microwave is directly applied to the substrate. 7. The plasma processing method according to claim 1, wherein a microwave having a frequency of 1 GHz or more is used. 8. A vacuum vessel, and mutually parallel pair of parallel plates provided in the vacuum chamber, a gas introducing means for introducing a gas between the parallel plates, microwaves between the parallel plates relative the plasma processing apparatus characterized in that it comprises a luma microwave supplying device to directly input from the tube inlet to direction. 9. The plasma processing according to claim 8, wherein a plurality of magnets are arranged in the vicinity of one of the parallel flat plates 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 said parallel plates. 11. The plasma processing apparatus according to claim 8, further comprising a high-frequency bias applying means for applying a high-frequency bias between said parallel plates. 12. A grid plate is provided between said parallel flat plates so that a plate surface of said grid plate is substantially parallel to said parallel flat plate surface, and said microwave input means is provided for one or other of said parallel flat plates. The plasma processing apparatus according to any one of claims 8 to 11, wherein the microwave is directly supplied between the flat plate and the grid plate. 13. The plasma processing apparatus according to claim 8, wherein the frequency of the microwave input by the microwave input means is 1 GHz or more.