JPH10162992A - Plasma processing equipment - Google Patents

Abstract

[PROBLEMS] To provide a high-frequency inductively coupled plasma processing apparatus capable of uniformly introducing a processing gas into a processing chamber and forming a uniform electric field. SOLUTION: A processing chamber 102a of an etching apparatus 100 is provided.
High frequency antenna layer 118 of dielectric 118 disposed on top
c, the inner peripheral portion 120b, the outer peripheral portion 120c, and the intermediate portion 12
A high-frequency antenna 120 made of Od is formed. A first gas supply path 152 and a second gas supply path 150 are arranged in a processing gas supply layer 118d below an intermediate portion 120d where a high-frequency antenna 120 is roughly arranged and is in a high electric field region.
The processing gas is supplied to the gas supply holes 15 of the second gas supply path 150.
0a is uniformly discharged into the processing chamber 102a. The plasma is excited in the gas supply path 151, the electric field transmitted into the processing chamber 102a is attenuated, a uniform electric field is formed in the processing chamber 102a, and a plasma having a uniform density is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly, to an inductively coupled plasma processing apparatus that applies an RF power to a RF antenna to excite an induced plasma in a processing chamber via a dielectric.

[0002]

2. Description of the Related Art In recent years, with the ultra-high integration of semiconductor devices and LCDs, it has become necessary to perform ultra-fine processing in sub-micron units and further in sub-half micron units. In order to perform such a process using a plasma processing apparatus, a high vacuum atmosphere (for example, 1 to 70 mTorr) is required.
Therefore, it is important to control high-density plasma with high accuracy, and the plasma can be applied to large-diameter semiconductor wafers and large-size LCD glass substrates.
It is necessary to have a large area and high uniformity.

Many approaches have been taken to establish a new plasma source in response to such technical requirements. For example, European Patent Publication No. 379828 discloses a high-frequency inductively coupled plasma processing apparatus using a high-frequency antenna. As shown in FIG. 8, the high-frequency induction plasma processing apparatus 10 has one surface (a ceiling surface) of a processing chamber 16 facing a mounting table 14 on which the object 12 is mounted.
Is composed of a dielectric material 18 such as quartz glass, and a high-frequency antenna 20 composed of, for example, a spiral coil is installed on the outer wall surface thereof. As a result, an electric field by a high frequency is formed in the processing chamber 16, and electrons flowing in the electric field collide with neutral particles of the processing gas to ionize the gas to generate plasma. A high-frequency power supply 26 is provided on the mounting table 14 so as to promote the incidence of the plasma flow on the processing surface of the processing target 12.
Higher bias power can be applied. At the bottom of the processing chamber 16, an exhaust port 28 communicating with an exhaust unit (not shown) is provided so that the inside of the processing chamber 16 has a predetermined pressure atmosphere, and a dielectric 18 forming a ceiling surface of the processing chamber 16 is provided. A processing gas inlet 30 for introducing a predetermined processing gas into the processing chamber 16 is provided at a central portion of the processing chamber 16.

[0004]

However, in the conventional high frequency inductively coupled plasma processing apparatus as described above,
The high frequency excited by the high frequency antenna is introduced into the processing chamber through the dielectric to form an electric field, and the electric field accelerates electrons and ions in the processing gas introduced into the processing chamber, and the electrons and ions are accelerated. The plasma is excited by colliding with each other.
Therefore, in order to generate high-density and uniform plasma, the processing gas must be uniformly introduced into the processing chamber and the electric field must be uniform.

As described above, in order to uniformly introduce the processing gas into the processing chamber, a processing gas supply means, for example, a so-called shower head is provided at a position opposed to the processing surface of the processing object mounted on the mounting table. It is preferable that a gas is blown uniformly to the surface of the object to be processed. In a general shower head, a hollow diffusion chamber constituting a buffer portion is formed in the shower head, and after temporarily storing a processing gas introduced from a gas inlet in the diffusion chamber, the processing gas is diffused. It is configured to discharge in the direction of the processing surface of the object to be processed through a number of small holes (gas discharge holes) in a substantially shower shape that communicates with the processing chamber.

However, when the above-described showerhead structure is employed in the inductively coupled plasma processing apparatus, a diffusion chamber is interposed between the high-frequency antenna and the processing chamber. As a result, the processing gas in the diffusion chamber is turned into plasma by a part of the high-frequency energy (electric field) oscillated from the high-frequency antenna, and the high-frequency energy introduced into the processing chamber decreases. Even when the plasma is excited in the diffusion chamber, if the plasma is supplied into the processing chamber, the plasma density in the processing chamber does not decrease. However, since the gas discharge holes are very small in diameter, the gas discharge holes are very small. The excited plasma cannot pass through the gas discharge hole. As a result, when a showerhead structure is applied to the apparatus, the plasma density decreases with a decrease in high-frequency energy transmitted into the processing chamber.

The present invention has been made in view of the above-mentioned problems of the conventional high-frequency inductively coupled plasma processing apparatus, and a first object of the present invention is to transmit a signal transmitted from a high-frequency antenna into a processing chamber. It is an object of the present invention to provide a new and improved high-frequency inductively coupled plasma processing apparatus capable of homogenizing high-frequency energy and exciting a plasma having a uniform density in a processing chamber.

Further, in the above-mentioned conventional apparatus, since the high-frequency antenna is installed outside the processing chamber via the dielectric wall, it resists the pressure difference between the reduced pressure atmosphere inside the processing chamber and the atmospheric pressure atmosphere outside the processing chamber. Therefore, the thickness of the dielectric wall had to be increased. Such a configuration in which the processing gas supply means is provided on the lower surface side of the thick dielectric wall is adopted in that the electric field excited by the high frequency antenna is further weakened, and the efficiency of using high frequency energy is deteriorated. Was difficult. Such a problem is particularly remarkable in a large-sized plasma processing apparatus for processing a large-diameter semiconductor wafer or a large-area LCD glass substrate.

The present invention has been made in view of the above problems of the conventional high frequency inductively coupled plasma processing apparatus, and a second object of the present invention is to reduce the influence of the electric field generated in the processing chamber. It is an object of the present invention to provide a new and improved high-frequency inductively coupled plasma processing apparatus capable of generating a high-density and uniform plasma by introducing a uniform processing gas into a processing chamber without giving it.

[0010]

In order to solve the above-mentioned problems, the present invention applies high-frequency power to a high-frequency antenna to excite inductively-coupled plasma into a processing chamber via a dielectric material, thereby to reduce the frequency of the object in the processing chamber. An object of the present invention is to provide a plasma processing apparatus configured to perform predetermined plasma processing on a processing body. In the plasma processing apparatus, gas supply means is formed on the side of the dielectric facing the object to be processed, and the gas supply means comprises a dielectric body, a gas supply An inlet, one or more gas paths extending in a substantially horizontal direction from the gas supply inlet into the dielectric body, and branching off from the gas path to open on the side facing the object to be processed, and One or more gas supply ports having a small diameter.

According to this configuration, since the gas supply means is formed in the dielectric main body, the gas supply means does not affect the high frequency excited from the high frequency antenna or the electric field generated in the processing chamber, so that the gas supply means is uniform. Can be introduced into the processing chamber, so that a high-density and uniform plasma can perform a uniform plasma process on the object to be processed.

Further, the dielectric can be arranged so as to be in contact with the inner wall surface of the processing chamber which is made of a conductive material and is grounded. Can be buried inside the body.

According to this configuration, since the dielectric is disposed in the processing chamber and the high-frequency antenna is formed in the dielectric, the thickness of the dielectric can be appropriately adjusted without considering the pressure difference inside and outside the processing chamber. Can be set. As a result, a relatively strong electric field can be formed in the processing chamber by reducing the thickness of the dielectric between the high-frequency antenna side surface and the processing object side surface, and high-density plasma can be excited. .

Further, since the gas path can be routed through the dielectric body so as not to obstruct the electric field path excited from the high frequency antenna and reaching the processing chamber as in the invention of the third aspect, Thus, a uniform processing gas can be introduced into the processing chamber without making the electric field non-uniform, for example, by weakening the electric field.

Further, the gas path is controlled by controlling an electric field path which is excited from the high-frequency antenna and reaches the processing chamber to make the electric field density in the processing chamber uniform. Since the plasma can be circulated in the body, a plasma having a uniform density is excited in the processing chamber, and uniform processing can be performed over the entire surface of the processing surface of the processing object.

The high-frequency antenna may be, for example,
As in the invention described in (1), there is a densely arranged area and a coarsely arranged area, and at least the gas path may extend around the dielectric body corresponding to the area where the high-frequency antenna is coarsely arranged. it can.

According to such a configuration, the gas path is formed in a dielectric material corresponding to a region where the high-frequency antenna is coarsely arranged, that is, a region where an electric field is formed relatively higher than a region where the high-frequency antenna is densely arranged. Since it is provided in the main body, it is possible to attenuate the electric field transmitted into the processing chamber from the area where the high-frequency antenna is roughly arranged by exciting the plasma in the gas path. As a result, the electric field transmitted into the processing chamber from the region where the high-frequency antennas are densely arranged and the region where the high-frequency antennas are coarsely arranged can be made uniform. can do.

The gas path may be constituted by a plurality of branch paths, and one or more gas supply ports may be provided in each branch path. The gas flow lengths from the inlet to the respective openings of the respective second gas paths can be configured to be substantially the same.

According to this configuration, the conductance of the processing gas introduced into the processing chamber from each opening of each gas supply port becomes substantially the same, so that a uniform processing gas is introduced into the processing chamber from each opening. Can be introduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a plasma processing apparatus according to the present invention is applied to a high-frequency inductively coupled plasma etching apparatus for a glass substrate for an LCD will be described below in detail with reference to the accompanying drawings. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description will be omitted.

The plasma etching apparatus 100 shown in FIG.
Has a processing container 102 formed in a cylindrical or rectangular prismatic shape made of a conductive material, for example, aluminum or stainless steel whose surface is anodized,
The predetermined etching process is performed in a processing chamber 102a formed in the processing container 102.

The processing vessel 102 is grounded, and further has a substantially rectangular shape at the bottom thereof for mounting an object to be processed, for example, an LCD glass substrate (hereinafter, referred to as "LCD substrate") L. A mounting table 106 is provided. The mounting table 106 includes, for example, an electrode unit 1 made of a conductive material such as aluminum or stainless steel whose surface has been subjected to anodizing treatment.
06a and an electrode protection portion 10 made of an insulating material such as ceramics covering portions other than the mounting surface of the electrode portion 106a.
6b. The mounting table 106 is mounted on an elevating shaft 106 c penetrating the bottom of the processing container 102. The elevating shaft 106c can be moved up and down by an elevating mechanism (not shown), and the entire mounting table 106 can be moved up and down as needed. A shrinkable bellows 108 for keeping the inside of the processing chamber 102a airtight is provided on the outer periphery of the elevating shaft 106c.

A high-frequency power supply 112 is electrically connected to the electrode portion 106a of the mounting table 106 via a matching circuit 110, and by applying a predetermined high-frequency power, for example, 2 MHz high-frequency power during plasma processing. By generating a bias potential, the plasma excited in the processing chamber 102a can be effectively drawn into the processing surface of the LCD substrate L. In the apparatus shown in FIG.
The configuration for applying high frequency power for bias was shown in
A configuration in which the mounting table 106 is simply grounded may be adopted.

Further, a cooling jacket 114 is provided inside the electrode portion 106a of the mounting table 106. In the cooling jacket 114, for example, a heating medium such as ethylene glycol whose temperature is controlled by a chiller is introduced.
4a, and the introduced ethylene glycol circulates through the cooling jacket 114 to generate cold heat. With this configuration, the cryogenic heat of ethylene glycol is transferred from the cooling jacket 114 to the LCD via the mounting table 106.
It is possible to transfer heat to the substrate L and control the temperature of the processing surface of the LCD substrate L to a desired temperature. The ethylene glycol circulated through the cooling jacket 114 is discharged out of the container through the heat medium discharge pipe 114b. Although omitted in the apparatus shown in FIG. 1, a heating means such as a heater may be provided on the mounting table 106 to control the temperature of the processing surface of the LCD substrate L. A large number of holes 115a are formed in the mounting surface of the mounting table 106,
From 15, the heat transfer efficiency is increased by supplying a predetermined heat transfer gas, for example, a helium gas, between the mounting surface of the mounting table 106 and the back surface of the LCD substrate L, so that even under a reduced pressure atmosphere, the heat transfer efficiency is improved. It is possible to control the temperature of the LCD substrate L.

A clamp frame 116 capable of clamping the outer edge of the LCD substrate L is provided above the mounting table 106. This clamp frame 1
The LCD substrate L is supported by, for example, four support columns 116a which stand upright around the mounting table 106.
Is raised, and the clamp frame 116 is brought into contact with the outer edge of the LCD substrate L, whereby the LCD substrate L can be mounted and fixed on the mounting table 106. The mounting table 106 is also provided with a pusher pin (not shown), and by raising and lowering the pusher pin, the LCD substrate L can be mounted on the mounting table 106 or can be lifted from the mounting table 106. It is.

Further, a dielectric 118 in which a high-frequency antenna 120 is embedded is provided so as to be in contact with the top plate 102b of the processing container 102 which is substantially opposed to the mounting surface of the LCD board L of the mounting table 106. The dielectric 118 has a laminated structure, and in the illustrated example, has a four-layer structure composed of dielectric members. That is, the top plate 102
From the b side, a Pyrex layer 118a, a quartz layer 118b,
It is composed of a high-frequency antenna layer 118c in which a high-frequency antenna 120 is embedded in a dielectric material such as mica, and a processing gas supply layer 118d according to the present embodiment in which a processing gas path is provided in quartz. In addition, it is preferable to use a material having the same coefficient of thermal expansion as the dielectric material to be laminated so that when the high-frequency antenna 120 is heated by application of high-frequency power, the heat does not cause a phenomenon such as separation. Further, in the illustrated example, mica or Pyrex is used in view of workability and cost, but it is of course possible to constitute all of them from a quartz layer. Also, the number of layers to be laminated is not limited to four, and a number of dielectric layers can be laminated. Alternatively, it is also possible to simply embed a high-frequency antenna in a dielectric material without using a laminated structure.

The top plate 102b of the processing container 102
Is detachable together with the dielectric 118 and the high-frequency antenna 120, and is configured so that maintenance of the dielectric 118 and the high-frequency antenna 120 can be easily performed.

As shown in FIG. 2, the high-frequency antenna layer 118c has a structure in which a strip-shaped conductor, for example, a copper plate, an aluminum plate, a stainless steel plate, or the like is sandwiched as a high-frequency antenna 120 in a dielectric layer 118c such as mica. ing. Here, since the coefficient of thermal expansion of the dielectric layer 118c such as mica and the high-frequency antenna 120 are different, high-frequency power is applied to the high-frequency antenna 120 and the high-frequency antenna 12
When 0 and its surroundings are heated, distortion may occur due to thermal expansion of the high-frequency antenna 120, and a phenomenon such as peeling may occur. In this regard, in the device according to the present embodiment, since the notch 120a is provided in some places of the high-frequency antenna 120, the notch 120a is provided.
Accordingly, the thermal expansion of the high-frequency antenna 120 is absorbed, distortion is hardly generated, and undesired phenomena such as peeling can be prevented.

The high-frequency antenna 120 is mounted on the mounting table 1.
An inner peripheral portion 120b in which a band-shaped conductor is wound several turns in a substantially spiral shape around a portion opposed to the center point of the LCD substrate L on the LCD substrate 06, and is disposed at a predetermined distance from the inner peripheral portion 120b. In the same manner as the inner peripheral portion 120b, the belt-shaped conductor is constituted by an outer peripheral portion 120c in which several turns are wound substantially spirally. Further, an intermediate portion 120d where the high-frequency antenna 120 is coarsely formed is formed between the inner peripheral portion 120b and the outer peripheral portion 120c where the high-frequency antenna 120 is densely arranged, and a strip-shaped conductive member arranged in the intermediate portion 120d. The body connects the inner peripheral part 120b and the outer peripheral part 120c. In the illustrated example, the high-frequency antenna 120 is formed in a spiral shape having several turns. However, the high-frequency antenna 120 only needs to have an antenna function for generating plasma. The number of turns may be reduced.

Referring again to FIG. 1, a feed path 122a and a ground path 122b are provided through the Pyrex layer 118a and the quartz layer 118b and further to the high-frequency antenna 120 in the mica layer 118c. A high-frequency power supply 126 is connected to the power supply path 122a via a matching circuit 124.
A predetermined frequency, for example, 13.
A high frequency power of 56 MHz can be applied to the high frequency antenna 120 to excite the induction plasma in the processing chamber 102a.

With the above-described configuration, the dielectric 118 and the high-frequency antenna 120 of the etching apparatus 100 according to the present embodiment are integrally provided inside the processing vessel 102. Irrespective of the pressure difference, the thickness of the dielectric layer from the high-frequency antenna 120 to the LCD substrate L can be reduced. Therefore,
Since a stronger electric field can be formed in the processing chamber 102a by high-frequency power applied to the high-frequency antenna 120 from the high-frequency power supply 126, high-frequency energy can be effectively used.

Here, the processing gas supply layer 118d according to the present embodiment will be described with reference to FIG. As described above, the processing gas supply layer 118d is made of a dielectric material, for example, quartz, and has a plurality of, for example, six second gas paths 150 having a substantially rectangular cross section.
Are formed in a substantially ladder shape from the vicinity of the side wall of the processing chamber 102a toward the substantially opposite direction. A large number of gas supply holes 150a communicating with the second gas path 150 are formed in the surface of the processing gas supply layer 118d on the mounting table 106 side.

At both ends of the second gas path 150,
A first gas path 152 having a substantially larger cross-sectional area than the second gas path 150 is connected, and each of the second gas paths 150 and the first gas path 152 communicate with each other. Further, the second gas path 150 of the first gas path 152
A predetermined processing gas from a processing gas source 130 to be described later is supplied to the first gas path 1
A gas supply inlet 154 for introduction into the interior 52 is connected.

Accordingly, a predetermined processing gas, for example, CF in the case of an oxide film processing, is supplied from the processing gas source 130 through the flow control device (MFC) 132 and the gas supply inlet 154.
BCl ₃ + Cl _{2 for 4} gas, aluminum film treatment
Is supplied into the first gas path 152, and then supplied to each second gas path 150, and the second gas path 1
By blowing the gas into the processing chamber 102a from each gas supply hole 150a provided in the processing chamber 102 in the form of a shower, the processing gas concentration in the processing chamber 102a is made uniform, so that a plasma having a uniform density is excited into the processing chamber 102a. It is possible.

The processing gas supply layer 118d is made of a dielectric material.
A gas path 151 is formed inside 8d. Therefore, in order to sufficiently transmit the high-frequency energy (electric field) oscillated from the high-frequency antenna 120 to the processing chamber 102a via the processing gas supply layer 118d, the gas path 15 is required.
1 must be considered. Therefore, according to the knowledge of the inventor, the dielectric portion 11 of the processing gas supply layer 118d with respect to the out-of-plane contour of the mounting surface of the mounting table 106 is provided.
9, ie, the projected area (A1) of the portion where the gas path 151 is not formed, and the projected area (A1) of the gas path 151.
2) is desirably set so that A2 / (A1 + A2) is less than 0.4, preferably 0.15 to 0.25.

Next, referring to FIG.
The process of generating plasma in a will be described. First,
Processing chamber 1 in which various conditions such as a predetermined reduced pressure atmosphere are prepared
After a predetermined processing gas, for example, a mixed gas of BCl ₃ + Cl ₂ is introduced from the second gas path 150 into the 02a as described above, a predetermined high-frequency power is applied to the high-frequency antenna 120 as described above. Then, a high frequency is excited, and the high frequency generates an electric field in the processing chamber 102a through the processing gas supply layer 118d made of a dielectric material, for example, quartz. The electric field causes electrons in a predetermined processing gas introduced into the processing chamber 102a to collide with neutral particles in the processing gas to excite plasma.
At this time, the high frequency is applied to each of the first gas paths 152 and each of the second gas paths 150 provided in the processing gas supply layer 118d.
Is introduced into the processing chamber 102a from the dielectric portion between the two, and a high-density and uniform plasma can be generated.

By the way, an electric field is also generated in the first gas path 152 and the second gas path 150 due to the high frequency excited from the high frequency antenna 120, so that the processing gas therein is dissociated to generate plasma. As a result, when the high-frequency energy oscillated from the high-frequency antenna 120 enters the gas path 151, the high-frequency energy is not substantially transmitted to the processing chamber 102a. However, the high-frequency antenna 12
Since there are relatively many dielectric portions 119 that can sufficiently transmit high-frequency energy oscillated from zero,
Sufficient plasma can be generated in the processing chamber 102a.

A route for circulating cooling water is provided in the dielectric 118, and the high-frequency antenna 120 heated by application of high-frequency power is cooled by circulating the cooling water. It is also possible to configure to extend the life of the 118.

As described above, in the etching apparatus 100 according to the present embodiment, since the high-frequency antenna 120 is integrally provided in the dielectric 118 inside the processing container 102, the atmospheric pressure and the processing chamber 102a Regardless of the pressure difference between the inside and the
The thickness of the dielectric layer on the side can be reduced, and a strong electric field can be formed in the processing chamber 102a. For this reason, even if the gas supply inlet 154, the first gas path 152, and the second gas path 150, which are processing gas supply means, are provided in the processing gas supply layer 118d between the high-frequency antenna 120 and the LCD substrate L, The electric field generated in the processing chamber 102a is not affected. Further, since the processing gas is uniformly introduced into the processing chamber 102a from the gas supply holes 150a of the second gas path 150a, it is possible to generate high-density and uniform plasma, which has been difficult in the related art.
A uniform plasma process can be performed on the CD substrate L.

The processing gas supply layer 118d is composed of the portion where the gas path 151 is formed as described above and the dielectric portion 119 where the gas path 151 is not formed. The transmittance of the high-frequency energy oscillated from the antenna 120 into the processing chamber 102a is different. Therefore, considering the uniformity of the plasma excited in the processing chamber 102a, the gas path 151 and the high-frequency antenna 120 are arranged substantially line-symmetrically or substantially point-symmetrically with respect to the center of the mounting surface of the mounting table 106. Is preferred.

Further, from the high-frequency antenna 120 to the processing room 1
As shown in FIG. 5, the distribution of the electric field energy intensity supplied in 02a becomes strongest in the intermediate portion 120d where the high-frequency antenna 120 is coarsely arranged. Therefore, in the present embodiment, as shown in FIG. 6, the first gas path 152 and the second gas path 150 are formed in the processing gas supply layer 118d below the intermediate portion 120d having the highest electric field energy. It is configured to relatively reduce the electric field energy supplied into the processing chamber 102a from the portion. As a result, the electric field intensity distribution formed in the processing chamber 102a is made uniform, so that the uniformity of the plasma density can be improved.

Referring back to FIG. 1, an exhaust pipe 136 is connected to the bottom of the processing chamber 102, and the processing chamber 102a
The inside of the processing chamber 102a is configured to be able to exhaust the atmosphere in the chamber by an exhaust means (not shown), for example, a vacuum pump.
Can be evacuated to an arbitrary degree of reduced pressure.

A gate valve 138 is provided on the side of the processing container 102, and an unprocessed LCD substrate L is moved from a load lock chamber installed adjacently by a transfer mechanism having a transfer arm or the like. Can be carried into the processing chamber 102a, and the processed LCD substrate L can be carried out.

Next, the operation of the plasma etching apparatus according to the embodiment configured as described above will be described.

First, an LCD is connected via a gate valve 138.
The substrate L is accommodated in the processing chamber 102a by a transfer arm (not shown). At this time, the mounting table 106 is at the lower position, and a pusher pin (not shown) is lifted. The transfer arm (not shown) places the LCD substrate L on the pusher pin (not shown), and the processing vessel 102 is moved from the gate valve 138 to the processing vessel 102. Evacuate outside. Next, the pusher pin (not shown) descends, and L
The CD substrate L is mounted on the mounting surface of the mounting table 106. Next, the mounting table 106 is lifted by a lifting mechanism (not shown),
The periphery of the LCD substrate L is pressed against the lower surface of the clamp 106, and the LCD substrate L is fixed to the mounting table 106.

The inside of the processing chamber 102a is evacuated by a vacuum pump (not shown) connected to the exhaust pipe 136, and is simultaneously provided in each second gas path 150 in the processing gas supply layer 118d according to the present embodiment. Each gas supply hole 1
From 50a, a predetermined processing gas, for example, CF ₄ gas in the case of oxide film processing, and BCl ₃ gas in the case of aluminum film processing
The mixed gas of + Cl ₂ is uniformly introduced into the processing chamber 102a, and the processing chamber 102a is maintained in a high vacuum state of, for example, about 30 mTorr.

Then, a high-frequency energy of 13.56 MHz, for example, is applied from a high-frequency power supply 126 via a matching circuit 124 to a high-frequency antenna 120 embedded in a high-frequency antenna layer 118 c of the dielectric 118. Then
An electric field is formed in the processing chamber 102a by the induction action of the inductance component of the high-frequency antenna 120. that time,
Since a uniform processing gas is introduced into the processing chamber 102a from each gas supply hole 150a according to the present embodiment, a high-density and uniform plasma can be generated in the processing chamber 102a. Can be subjected to uniform plasma processing.

The plasma excited in the processing chamber 102a as described above moves in the direction of the LCD substrate L on the mounting table 106 by the bias potential applied to the mounting table 106, and the desired plasma is applied to the processing surface. Can be applied. After the predetermined etching process is completed, the processed LCD substrate L is carried out to the load lock chamber via the gate valve 138 by the transfer arm (not shown), and a series of operations is completed.

While the embodiment in which the plasma processing apparatus according to the present invention is applied to an etching apparatus for an LCD substrate has been described with reference to the accompanying drawings, the present invention is not limited to such an example. A person skilled in the art can make various modifications and changes within the scope of the technical idea described in the claims, and these naturally belong to the technical scope of the present invention. I understand.

For example, in the above embodiment, the second
Although an example has been described in which the shape of the gas path is substantially ladder-shaped, the present invention is not limited to such a configuration. For example, as shown in FIG. 7, the processing gas supply layer 118d of the dielectric 118
Inside, a first gas path 202 extending substantially in the vertical direction is connected to a gas supply inlet 200 extending substantially in the direction of the center of the processing chamber 102a.
For example, a second gas path 204 extending substantially radially in four directions is connected to both ends of the second gas path 02, and a gas supply hole 204a is provided at an end of the second gas path 204. At this time, since the distance between the gas supply inlet 200 and each gas supply hole 204a is configured to be the same, the conductance from the gas supply inlet 200 to each gas supply hole 204a becomes substantially the same. As a result, the processing gas can be uniformly dispersed in the processing chamber 102a.

Further, in the above embodiment, the configuration in which the high-frequency antenna 120 is provided in the dielectric 118 has been described as an example. However, the present invention is not limited to such a configuration, and the high-frequency antenna is provided in the upper part of the processing container. The present invention is also applicable to a plasma processing apparatus provided outside a dielectric wall.

Further, in the above embodiment, the second
Although the configuration in which the gas path 150 is provided near the lower portion between the high-frequency antennas 120 has been described as an example, the present invention is not limited to this configuration, and the present invention is also applicable to a configuration in which the second gas path is provided below the high-frequency antenna. It is possible.

Further, in the above embodiment,
An example in which the LCD substrate L is processed as an object to be processed has been described.
The present invention is also applicable to a processing apparatus using a semiconductor wafer as a processing target. In the above embodiment, an example in which the present invention is applied to an etching apparatus has been described.
The present invention can be applied to various apparatuses using plasma, for example, an ashing apparatus and a plasma CVD apparatus.

[0054]

As described above, according to the plasma processing apparatus of the present invention, since the high-frequency antenna is integrally provided in the dielectric inside the processing vessel, the atmospheric pressure and the pressure in the processing chamber are reduced. Regardless of the difference, the thickness of the dielectric layer on the object side can be reduced from the high-frequency antenna, and a strong electric field can be generated in the processing chamber. Therefore, in the dielectric between the high-frequency antenna and the object,
Even if a gas supply inlet, a gas path, and a gas supply hole, which are means for supplying a processing gas, are provided, the electric field generated in the processing chamber is not affected. In addition, since the processing gas is uniformly introduced into the processing chamber from the gas supply holes, it is possible to generate a high-density and uniform plasma, which has been difficult in the past, and to perform a uniform plasma processing on the object to be processed. be able to. Furthermore, since the conductance of the processing gas introduced into the processing chamber from each opening of each gas supply port of each gas path becomes substantially the same, a uniform processing gas is introduced into the processing chamber from each opening. be able to.

Further, since a gas path is formed on the processing chamber side in a region where the high-frequency antenna is roughly arranged, that is, a region where a relatively high electric field is formed, by exciting plasma in the gas path, The electric field supplied into the processing chamber from the region can be attenuated. As a result, a uniform electric field can be formed in the processing chamber, so that high-density plasma can be excited uniformly and stably.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an etching apparatus to which the present invention can be applied.

2 is a schematic explanatory view showing a schematic configuration of a high-frequency antenna embedded in a dielectric of the etching apparatus shown in FIG.

FIG. 3 is a schematic explanatory view showing one embodiment of a processing gas supply path of the etching apparatus shown in FIG. 1;

FIG. 4 is a schematic explanatory view showing a plasma generation process in a processing chamber in the etching apparatus shown in FIG.

5 is a schematic explanatory diagram for explaining an intensity distribution of electric field energy oscillated into a processing chamber from a high-frequency antenna of the etching apparatus shown in FIG. 1;

FIG. 6 is a schematic explanatory view for explaining an arrangement of a high-frequency antenna and a processing gas supply path of the etching apparatus shown in FIG. 1;

FIG. 7 is a schematic explanatory view showing another embodiment of the gas supply path in the plasma processing apparatus according to the present invention.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a conventional high-frequency inductively coupled plasma processing apparatus.

[Explanation of symbols]

 Reference Signs List 100 etching apparatus 102a processing chamber 106 mounting table 118 dielectric 118c high-frequency antenna layer 118d processing gas supply layer 120 high-frequency antenna 120b inner peripheral part 120c outer peripheral part 120d intermediate part 150 second gas path 150a gas supply hole 152 first gas path 154 gas Supply inlet

Claims (6)

[Claims] 1. A structure in which a high-frequency power is applied to a high-frequency antenna to excite inductively coupled plasma into a processing chamber via a dielectric, and to perform a predetermined plasma processing on an object to be processed in the processing chamber. In the plasma processing apparatus, a gas supply means is formed on a surface of the dielectric facing the object to be processed; the gas supply means comprises a dielectric body, a gas supply inlet, and a gas supply inlet. One or more gas paths extending in a substantially horizontal direction in the body, and one or more gas paths branched from the gas paths and opening on the side facing the object to be processed and having a smaller diameter than the gas paths. A plasma processing apparatus comprising: a gas supply port. 2. The method according to claim 1, wherein the dielectric is made of a conductive material and is disposed in contact with an inner wall surface of the processing chamber, which is grounded; and the high-frequency antenna is embedded in the dielectric. The plasma processing apparatus according to claim 1. 3. The gas path is routed inside the dielectric body so as not to obstruct an electric field path excited from the high frequency antenna and reaching the processing chamber.
The plasma processing apparatus according to claim 1. 4. The gas path is routed in the dielectric main body so as to control an electric field path excited from the high frequency antenna and reaching the processing chamber so as to equalize an electric field density in the processing chamber. The plasma processing apparatus according to any one of claims 1, 2, and 3, wherein: 5. The high-frequency antenna has a densely arranged region and a coarsely arranged region, and at least the gas path is provided in the dielectric material corresponding to the region where the high-frequency antenna is roughly arranged. Characterized by being circulated throughout the body.
The plasma processing apparatus according to claim 1. 6. The gas path is composed of a plurality of branch paths; further, in a configuration in which one or two or more gas supply ports are provided in each branch path, the gas supply inlet is connected to each of the second gas paths. The plasma processing apparatus according to any one of claims 1, 2, 3, 4, and 5, wherein a gas flow length reaching each of the openings is substantially the same.