JP3153768B2 - Plasma processing equipment - 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 apparatus for performing a plasma process on an object to be processed, for example, a semiconductor wafer or an LCD substrate, in a processing chamber.
In particular, the present invention relates to an inductively coupled plasma processing apparatus that excites inductively coupled plasma in a processing chamber by applying high frequency power to a high frequency antenna.

[0002]

2. Description of the Related Art Conventionally, a parallel plate type plasma processing apparatus using a high frequency (RF) has been widely used as an apparatus for performing a plasma processing on an object to be processed, for example, a semiconductor wafer or an LCD substrate in a processing chamber. I have. Such a parallel plate type plasma processing apparatus generates a plasma between both electrodes by applying a high frequency to one or both electrodes, and a self-bias potential difference between the plasma and the object to be processed. The plasma flow is caused to flow into the processing surface of the object to be processed, and, for example, an etching process is performed.

[0003] However, in the above-mentioned parallel plate type plasma processing apparatus, it is difficult to carry out ultra-fine processing in sub-micron units and sub-half-micron units required with ultra-high integration of semiconductor devices.

That is, in order to carry out such a process by a plasma processing apparatus, a high vacuum atmosphere (for example, 1
It is important to control high-density plasma with high precision at ~ 70 mTorr), and the plasma must be large-area and highly uniform so that it can be used for large-diameter wafers and large LCD substrates. is necessary.

[0005] To meet such technical requirements, many approaches have been taken to establish a new plasma source. For example, European Patent Publication No. 379828 discloses a high-frequency inductively coupled plasma processing apparatus using a high-frequency antenna. In this high-frequency inductively coupled plasma processing apparatus 10, as shown in FIG. 8, one surface (ceiling surface) of a processing chamber 16 opposed to a mounting table 14 on which an object to be processed 12 is mounted is formed of a dielectric 18 such as quartz glass. The high frequency antenna 2 composed of, for example, a spiral coil
0, and a high frequency power supply 22
By applying high frequency power through the matching circuit 24, an electric field by high frequency is formed in the processing chamber 16,
Electrons flowing in the electric field collide with neutral particles of the processing gas to ionize the gas and generate plasma. A high-frequency power for biasing can be applied to the mounting table 14 from the high-frequency power supply 26 so as to promote the incidence of the plasma flow on the processing surface of the processing target 12. An exhaust port 28 communicating with an exhaust unit (not shown) is provided at the bottom of the processing chamber 16 so that the inside of the processing chamber 16 has a predetermined pressure atmosphere. 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.

[0006]

By the way, in the conventional high frequency inductively coupled plasma processing apparatus as described above,
Since the dielectric on which the high-frequency antenna is installed forms the ceiling of the processing chamber which is maintained in a high vacuum atmosphere, the thickness of the dielectric must be increased to withstand the pressure difference between the outside air and the processing chamber. As a result, there is a problem that utilization efficiency of energy input from the high-frequency power supply is poor. And
In particular, the above problem was remarkable in a large processing apparatus for processing a large-diameter wafer or a large-area LCD substrate.

[0007] In the conventional high-frequency inductively coupled plasma processing apparatus as described above, the high-frequency antenna is composed of a spiral coil arranged in a plane on the outer wall surface of the dielectric. Therefore, a stronger electric field is formed in the middle portion of the coil, and a denser plasma is generated in the middle region of the processing chamber. For this reason, as shown in FIG. 7A, the etching rate is different between the middle area (M) of the processing surface of the object to be processed and the center area (C) and the peripheral area (S). There was a problem that it was difficult to achieve. And this problem was remarkable especially in a large-sized processing apparatus.

The present invention has been made in view of the above-mentioned problems of the conventional high-frequency induction plasma processing apparatus, and has as its object to improve the efficiency of use of the energy supplied from the high-frequency power supply and to improve the efficiency. An object of the present invention is to provide a new and improved high-frequency induction plasma processing apparatus capable of generating a higher-density and uniform plasma even under vacuum conditions.

According to the first aspect of the present invention, an induction plasma is excited in a processing chamber by applying high-frequency power to a high-frequency antenna, and processing is performed on an object to be processed in the processing chamber. In the plasma processing apparatus configured to perform the process, the side wall made of a dielectric may be provided in the processing chamber.
To form a more enclosed antenna room,
The high-frequency antenna is installed, and the inside of the antenna room is large.
Maintained in a pressure atmosphere of less than atmospheric pressure, on the side of the antenna chamber
The wall is in contact with a grounded inner wall surface of the processing chamber.
Preferably, the interior of the antenna chamber is as described in claim 2.
Adjusted to below atmospheric pressure and above 100 Torr
can do.

Thus, according to claim 1 or 2 ,
Since the antenna chamber maintained at a pressure lower than the atmospheric pressure , preferably at a pressure of 100 Torr or higher , is installed in the processing chamber, the antenna chamber is compared with the thickness of a conventional dielectric which separates the atmospheric pressure from the high vacuum processing chamber. As a result, the thickness of the side wall of the antenna chamber can be reduced, and the high-frequency energy applied from the high-frequency power supply can be more efficiently propagated into the processing chamber. At the same time, since the side wall of the antenna chamber is in contact with the side surface of the processing chamber which is grounded, it is possible to concentrate an electric field due to a high frequency on the opposite surface (that is, the surface facing the object to be processed). Plasma can be generated.

According to a third aspect of the present invention, the plasma processing apparatus is further provided with a cooling gas supply / exhaust means for cooling the antenna chamber with a cooling gas. Therefore, the high-frequency antenna heated by applying high-frequency energy from the high-frequency power supply can be cooled by the cooling gas. Further, by adjusting the supply amount and / or the exhaust amount of the cooling gas, the pressure in the antenna chamber can be controlled to a desired pressure lower than the atmospheric pressure.

According to a fourth aspect of the present invention, in the plasma processing apparatus, the thickness of the wall of the antenna chamber facing the object to be processed is set to the thickness of the inner wall of the processing chamber in contact with the antenna chamber. It is preferable to form it thinner. According to such a configuration, a high-density electric field due to a high frequency is formed in the direction of the object to be processed, and the utilization efficiency of the high-frequency energy can be further increased to generate a high-density plasma in the processing chamber.

According to a fifth aspect of the present invention, in the plasma processing apparatus, when the processing surface of the object to be processed is divided into a central region, an intermediate region surrounding the central region, and a peripheral region surrounding the intermediate region. The high-frequency antenna portion disposed in the intermediate region of the antenna chamber belonging to the orthographic projection region of the intermediate region is more distant from the object than the high-frequency antenna portion disposed in another region of the antenna chamber. It can also be configured to do so. According to such a configuration, the electric field intensity in the processing chamber can be made uniform, and thus the plasma density can be made uniform.

According to a sixth aspect of the present invention, in the plasma processing apparatus, when the processing surface of the object to be processed is divided into a central region, an intermediate region surrounding the central region, and a peripheral region surrounding the intermediate region. The wall of the antenna chamber facing the object to be processed may be configured such that a wall portion belonging to the orthographic projection region of the intermediate region is thicker than a wall portion belonging to another region. According to such a configuration, it is possible to reduce the propagation of high-frequency energy in the intermediate region where a stronger electric field is generated, and the plasma that tends to have a high density in the intermediate region of the processing chamber is almost as large as the central region and the peripheral region. Density can be adjusted, and the plasma density can be made uniform.

[0015] Furthermore, as according to claim 7, in the plasma processing apparatus, the wall of the side facing the object to be processed of said antenna chamber, provided a process gas supply means, for example,
By supplying the processing gas into the processing chamber from a plurality of processing gas supply holes formed on the opposite surface side of the object to be processed, the distribution density of the processing gas is made uniform, and therefore, the plasma density generated in the processing chamber is made uniform. Can be planned.

[0016] Furthermore, as according to claim 8, in the plasma processing apparatus, the wall of the side facing the object to be processed of said antenna chamber, may be provided a coolant flow passage in which the refrigerant flows. With such a configuration, for example, it is possible to cool the overheated antenna chamber by flowing cold water through the coolant flow path.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a plasma processing apparatus according to the present invention is applied to an etching apparatus for an LCD substrate will be described below in detail with reference to the accompanying drawings.

A plasma etching apparatus 100 shown in FIG.
Has a processing container 102 formed in a cylindrical or rectangular prism shape made of a conductive material, for example, aluminum or the like.
2 is performed in a processing chamber 102a formed in the processing chamber 2.

The processing vessel 102 is grounded, and a substantially rectangular mounting table 106 for mounting an object to be processed, for example, an LCD substrate L, is provided at the bottom thereof. The mounting table 106 is made of, for example, an electrode portion 106a made of a conductive material such as aluminum or stainless steel whose surface has been subjected to oxidized alumite treatment, and an insulating material such as ceramics that covers a portion other than the mounting surface of the electrode portion 106a. And an electrode protection portion 106b. Mounting table 1
Reference numeral 06 denotes an elevating shaft 10 penetrated at the bottom of the processing vessel 102.
6c. This elevating shaft 106c is
It can be raised and lowered by a lifting mechanism (not shown), and the entire mounting table 106 can be raised and lowered 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 113 is electrically connected to the electrode portion 106a of the mounting table 106 via a matching circuit 111. When a predetermined high-frequency power, for example, 2 MHz, is applied during plasma processing. By generating a bias potential, 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 to
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, a heating medium such as ethylene glycol, whose temperature is controlled by a chiller, is supplied with a heating medium introduction pipe 11.
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 supplied from the cooling jacket 114 to the LCD
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. 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 erected 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 the LCD board L can be mounted on the mounting table 106 or lifted from the mounting table 106 by raising and lowering the pusher pin. It is.

An antenna chamber having a side wall made of a dielectric material such as quartz glass or ceramic so as to be in contact with the top plate 102b of the processing container 102 substantially opposed to the mounting surface of the LCD substrate L of the mounting table 106. 110 are provided. As shown in FIG. 2, a high-frequency antenna 112 in which a conductor, for example, a copper plate, aluminum, stainless steel, or the like is formed in a spiral, coil, or loop shape is disposed in the antenna chamber 110. Although the high-frequency antenna 112 shown in FIG. 2 is formed in a spiral shape having two turns, the antenna 112 may have a function of exhibiting an antenna function for generating plasma, and may have one turn as the frequency increases. .

A high-frequency power supply 116 for plasma generation is connected via a matching circuit 114 between both terminals of the high-frequency antenna 112, that is, between the terminals 112a and 112b.

The wall of the antenna room 110 is the LCD substrate L
The wall 110a on the side that contacts the ceiling 102b of the grounded processing container 102
It is configured to be thinner than the wall thickness. With such a configuration, the high frequency power supply 116 supplies the high frequency antenna 112
Since the electric field due to the high-frequency energy applied to the substrate can be concentrated on the LCD substrate L side, it is possible to generate a higher-density plasma in the processing chamber 102a as compared with a conventional apparatus.

A cooling gas supply pipe 116 and a cooling gas exhaust pipe 118 are connected to the antenna chamber 110, and a predetermined cooling gas is introduced into the antenna chamber 110, and when high-frequency energy is applied from the high-frequency power supply 116. The high-frequency antenna 112 overheated is cooled,
It is possible to extend the life of the device.

Further, as shown in FIG.
Refrigerant passage 113 through which a refrigerant such as cold water flows
Can be formed and flowing cold water can also form the antenna chamber 11.
0 can be prevented, and the life of the high-frequency antenna 112 can be extended.

Further, according to the above configuration, the cooling gas supply pipe 1
By adjusting the flow rate of the cooling gas introduced from the cooling gas outlet 16 into the antenna chamber 110 and / or the exhaust amount of the cooling gas exhausted from the cooling gas exhaust pipe 118, the antenna chamber 11
The pressure in 0 can be adjusted to less than atmospheric pressure, preferably to 100 Torr or more. By the way, in the conventional apparatus, since the high-frequency antenna is placed in the atmospheric pressure atmosphere, the thickness of the dielectric separating the atmosphere and the processing chamber is increased, and the pressure difference between the atmospheric pressure and the processing chamber pressure, for example, several tens mTorr. Had to be configured to resist. However, according to the present invention, since the pressure in the antenna chamber 110 is adjusted to be lower than the atmospheric pressure, the pressure difference between the antenna chamber 110 in which the high-frequency antenna 112 is installed and the processing chamber 102a can be reduced. Therefore, the wall 110a that separates the antenna chamber 110 from the inside of the processing chamber 102a can be formed to be thinner. As a result, the electric field due to the high-frequency energy applied from the high-frequency power supply 116 to the high-frequency antenna 112 can be more concentrated in the processing chamber 102a than in the conventional apparatus, and high-density plasma can be obtained.

Further, the processing gas supply section 118 will be described.
10 are arranged on the lower surface. This processing gas supply unit 11
8 has a structure in which a gas flow passage 128 is formed in a dielectric material such as quartz, and further includes a processing gas supply unit 118.
A large number of holes 128a communicating with the gas flow passage 128 are formed in the surface on the mounting table 106 side. Therefore, a predetermined processing gas supplied from the processing gas source 130 to the gas flow path 128 via the flow rate control device (MFC) 132, for example, HF ₄ gas when performing oxide film processing, or when performing aluminum film processing In the process, a mixed gas of BCl ₃ + Cl ₂ is blown out from the hole 128a into the processing chamber 120a in the form of a shower, so that the processing gas concentration in the processing chamber 102 is made uniform, so that a plasma having a uniform density is excited into the processing chamber 102a. Is possible.

An exhaust pipe 152 is connected to the bottom of the processing container 102 so that the atmosphere in the processing container 102 can be exhausted by an exhaust means (not shown), for example, a vacuum pump. The atmosphere in the processing chamber 102a can be evacuated to an arbitrary degree of reduced pressure.

A gate valve 154 is provided on the side of the processing container 102, and an unprocessed LCD substrate L is transferred from a load lock chamber installed adjacently by a transfer mechanism having a transfer arm or the like. The processed LCD substrate L can be carried out while being carried into the processing chamber 102a.

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

First, the LCD is operated via the gate valve 154.
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), 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 116, 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 an exhaust pipe 152, and at the same time, a predetermined processing gas, for example, an oxide film is processed through a processing gas supply port 150 provided on a side wall. HF ₄ gas in case
When performing an aluminum film treatment, a mixed gas of BCl ₃ + Cl ₂ is introduced into the processing chamber 102a, and the processing chamber is brought into a high vacuum state of about 30 mTorr, for example. In addition, a cooling gas is supplied into the antenna chamber 110 from a cooling gas supply port 116, and is maintained at a pressure less than the atmospheric pressure of, for example, about 100 Torr.

Then, high-frequency energy of, for example, 13.56 MHz is supplied from the high-frequency power source 116 through the matching circuit 114 to the high-frequency antenna 11 in the antenna chamber 110.
2 Then, an electric field is formed in the processing chamber 102a by the induction action of the inductance component of the high-frequency antenna 112. At this time, according to the present embodiment, the antenna chamber 110 is provided in contact with the ceiling 102b of the installed processing container 102, and the wall thickness of the wall 110a of the antenna chamber 110 on the side facing the object to be processed is Since it is formed thinner than the conventional one, a stronger electric field is formed in the processing chamber 102a as compared with the conventional apparatus.
As a result, higher density plasma can be generated in the processing chamber 102a.

The plasma generated in the processing chamber 102a as described above moves in the direction of the LCD substrate L on the mounting table 106 due to the bias potential applied to the mounting table 106, and a desired position with respect to the processing surface. An etching process can be performed. After the predetermined etching process is completed, the processed LCD substrate L is carried out to the load lock chamber via the gate valve 154.

As described above, the plasma processing apparatus according to the present invention has been described with reference to an embodiment in which the plasma processing apparatus is applied to an etching apparatus for an LCD substrate. 110 wall 11
0a is configured as a flat plate, so that the high-frequency antenna 1
A stronger electric field is formed in the middle portion where the 12 is densely arranged, and as a result, the plasma density in the middle region of the processing chamber is increased, and as shown in FIG. The etching rate (ER) between the central region (C) and the peripheral region (S) may be non-uniform.

In this specification, the area in the processing chamber or the antenna chamber belonging to the orthographic projection of the central area of the processing surface of the object to be processed is the central area (C), and the orthographic projection of the intermediate area surrounding the central area of the processing surface. A region in the processing chamber or the antenna room belonging to the intermediate region (M), and a region in the processing room or the antenna room belonging to the orthographic projection of the outer peripheral region (that is, the outermost region) surrounding the intermediate region of the processing surface is the peripheral region (S). ), The concepts of the central region (C), the intermediate region (M), and the peripheral region (S) are relative concepts, and include the dimensions and the mounting position of the object to be processed and the processing chamber. It is relatively determined according to the size and arrangement position of the antenna room.

According to another embodiment of the present invention, as described above, the central region (C), the intermediate region (M),
Various configurations for making different plasma densities in the peripheral region (S) uniform in the processing chamber can be added. Hereinafter, several embodiments for uniformizing the plasma density will be described. Of the constituent members used in these embodiments, those having the same functional configuration as the apparatus illustrated in FIG. 1 are denoted by the same reference numerals. Therefore, detailed description is omitted.

In the above embodiment, as shown in FIG. 2, as a result of using high-frequency antenna 112 to which high-frequency power is applied from one system of high-frequency power supply 116, intermediate region (M) and central region (C) In addition, the plasma density may be non-uniform in the peripheral region (S) (see FIG. 7).
(A)). On the other hand, according to another embodiment of the present invention, as shown in FIG.
2a and 222b, the matching circuit 224
a, 224b via two high-frequency antennas 202
It is also possible to adopt a configuration in which different high-frequency powers are applied to a and 202b. As shown in the drawing, by forming the high-frequency antenna in a multi-system structure, for example, the high-frequency antenna is densely arranged in a place where the plasma density is low, and / or a high-frequency power is applied to the place where the plasma density is high. On the other hand, the high-frequency antenna can be roughly arranged and / or a low-frequency power can be applied, so that the plasma density in the processing chamber can be made uniform. In the illustrated example, the electric field shield 21 surrounds the outer periphery of the first high-frequency antenna 202a.
0 so as not to cause mutual interference.
By arranging 2b, it is configured such that stronger radio waves can be supplied to the peripheral portion of the processing chamber where the plasma density tends to be thin.

Alternatively, as shown in FIG. 4, the intermediate portion 204M of the spiral high-frequency antenna 204 installed in the antenna chamber 110 is arranged so as to rise from the wall 110a of the antenna chamber 110 on the object side. , Wall 110
The distance between the intermediate portion 204M and the LCD substrate L can be wider than the distance between the center portion 204C (in the vicinity of the terminal 112a) and the peripheral portion 204S (in the vicinity of the terminal 112b) and the LCD substrate. As a result, it is possible to weaken the electric field in the middle region (M) of the processing chamber where the plasma density tends to increase, and as shown in FIG. (E
In-plane uniformity of R) can be achieved.

In the embodiment shown in FIG.
The intermediate portion 204M of the spiral high-frequency antenna 204 installed in the inside is connected to the wall 110 of the antenna chamber 110 on the object side.
5, the wall 206 of the antenna chamber 110 on the side of the object to be processed is placed in a portion belonging to the intermediate region (M) as shown in FIG. 5 in order to further stabilize the installation of the antenna. (206M) is a portion (206) belonging to another portion (the center region (C) and the peripheral region (S)).
C, 206S)) to form a stepped shape that rises toward the ceiling side of the processing chamber.
04 may be arranged.

Further, as shown in FIG. 6, the wall 208 of the antenna chamber 110 on the side of the object to be processed is attached to the intermediate portion 208 thereof.
The thickness of M can be configured to be thicker than the other portions, that is, the thickness of the central portion 208C and the peripheral portion 208S.
With such a configuration as well, it is possible to reduce the propagation power of the high-frequency energy in the intermediate region (M) where the plasma density tends to be high, so that the plasma density generated in the processing chamber can be made uniform. In the example shown,
The outer wall surface of the antenna chamber 110 on the object side is made flat,
The inner wall surface of the antenna chamber 110 is formed in an arm shape with a raised central portion, so that the thickness of the intermediate portion 208M is increased.
The inner wall surface of 0 may be flat, and the outer wall surface may be in the form of an arm whose central portion is raised toward the object to be processed, so that the central portion has a large thickness.

Further, in the embodiment shown in FIG. 6, the processing gas supply path 220 is provided in the wall 208 of the antenna chamber 110 on the side facing the LCD substrate L. The processing gas supply path 220 has a plurality of processing gas supply holes 222 that are opened on the outer wall surface of the wall 208 on the object side. According to this configuration, the processing gas is uniformly supplied into the processing chamber from the plurality of processing gas supply holes 222, so that the processing gas distribution density in the processing chamber 102a can be made more uniform, and thus the processing chamber 102a The density of the plasma generated inside can be made uniform.

As described above, the plasma processing apparatus according to the present invention has been described with reference to one embodiment in which the plasma processing apparatus is applied to an etching apparatus for an LCD substrate. However, the present invention is not limited to such an embodiment.
Within the scope of the technical idea described in the claims, those skilled in the art can make various modifications and changes, and these naturally belong to the technical scope of the present invention. I understand.

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

[0047]

As described above, according to the plasma processing apparatus constructed based on the present invention, the following excellent operational effects can be obtained.

According to claim 1 or 2 , the pressure is lower than the atmospheric pressure ,
Preferably, the antenna chamber maintained at a pressure atmosphere of 100 Torr or more is provided in the processing chamber, so that the antenna chamber is compared with the conventional dielectric material which separates the atmospheric pressure and the high vacuum processing chamber from each other. The thickness of the side wall of the chamber can be reduced, and the high-frequency energy applied from the high-frequency power supply can be more efficiently transmitted into the processing chamber. At the same time, since the side wall of the antenna chamber is in contact with the side surface of the processing chamber which is grounded, it is possible to concentrate an electric field due to a high frequency on the opposite surface (that is, the surface facing the object to be processed). Plasma can be generated.

According to the third aspect , the high-frequency antenna heated by application of high-frequency energy from the high-frequency power supply can be cooled by the cooling gas. Further, by adjusting the supply amount and / or the exhaust amount of the cooling gas, the pressure in the antenna chamber can be controlled to a desired pressure lower than the atmospheric pressure.

According to the fourth aspect , the thickness of the side wall of the antenna chamber facing the object to be processed is smaller than the thickness of the side wall of the processing chamber on the side of the processing chamber. Since it is formed in the direction, the utilization efficiency of the high-frequency energy can be further increased and high-density plasma can be generated in the processing chamber.

According to the fifth aspect , in the intermediate region of the processing chamber where a stronger electric field is apt to be formed, the space between the high-frequency antenna and the object to be processed is widened. The intensity of the electric field in the region can be made uniform, and as a result, the plasma density can be made uniform.

According to the sixth aspect , the propagation of high-frequency energy in the intermediate region where a stronger electric field is generated can be reduced, and the plasma which tends to have a high density in the intermediate region of the processing chamber is removed from the central region or the peripheral region. The density can be adjusted to the same level as the region, and the plasma density can be made uniform.

According to the seventh aspect , since the processing gas supply means is provided on the wall of the antenna chamber facing the object to be processed, for example, a plurality of processing gas formed on the opposing surface of the object to be processed is provided. By supplying the processing gas into the processing chamber from the gas supply holes, the distribution density of the processing gas can be made uniform, and therefore, the density of the plasma generated in the processing chamber can be made uniform.

According to the eighth aspect of the present invention, since a coolant flow path through which the coolant flows is provided on the wall of the antenna chamber facing the object to be processed, for example, cold water can flow through the coolant flow path. Thus, the overheated antenna room can be cooled.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment in which a plasma processing apparatus according to the present invention is applied to an etching apparatus for an LCD substrate.

FIG. 2 is a substantially horizontal cross-sectional view showing an arrangement of a high-frequency antenna of the plasma etching apparatus shown in FIG.

FIG. 3 is a schematic horizontal sectional view showing another embodiment of the high-frequency antenna applicable to the plasma processing apparatus according to the present invention.

FIG. 4 is a schematic vertical sectional view showing still another embodiment of a high-frequency antenna applicable to the plasma processing apparatus according to the present invention.

FIG. 5 is a substantially vertical sectional view showing still another embodiment of the high-frequency antenna and the antenna chamber applicable to the plasma processing apparatus according to the present invention.

FIG. 6 is a substantially vertical sectional view showing still another embodiment of a high-frequency antenna and an antenna chamber applicable to the plasma processing apparatus according to the present invention.

FIGS. 7A and 7B are explanatory diagrams showing the relationship between the arrangement of the high-frequency antenna and the etching rate. FIG. 7A shows a case where the high-frequency antenna is arranged in a plane, and FIG. 7B shows an arrangement in which an intermediate portion of the high-frequency antenna is raised. Each case is shown.

FIG. 8 is a schematic sectional view showing a schematic configuration of a conventional high frequency induction type plasma processing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 plasma etching apparatus 102 processing container 102 a processing chamber 102 B ceiling 106 mounting table 110 antenna chamber 110 a side wall of processed object 112 high frequency antenna 114 matching circuit 116 high frequency power supply 116 cooling gas supply port 118 cooling gas exhaust port

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI // C23C16 / 50 C23C16 / 50 (56) References JP-A-8-195297 (JP, A) JP-A-7-296989 (JP, A) JP-A-7-201495 (JP, A) JP-A-7-106096 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3065 B01J 19/08 C23F 4 / 00 H01L 21/205 H05H 1/46 C23C 16/50

Claims (8)

(57) [Claims] In a plasma processing apparatus configured to excite an induction plasma in a processing chamber by applying high-frequency power to a high-frequency antenna and to perform processing on an object to be processed in the processing chamber, The antenna surrounded by the dielectric side wall
A high-frequency antenna is formed in the antenna chamber.
The antenna room is maintained at a pressure less than atmospheric pressure.
And the side wall of the antenna chamber is inside the grounded processing chamber.
A plasma processing apparatus characterized by being in contact with a wall surface . 2. The interior of the antenna room is below atmospheric pressure.
And maintained in a pressure atmosphere of 100 Torr or more.
The plasma processing apparatus according to claim 1, wherein: 3. A cooling gas inside the antenna chamber.
With cooling gas supply / exhaust means for cooling
The plasma processing apparatus according to claim 1, wherein: 4. A process according to claim 1, wherein the thickness of the wall of the antenna chamber on the side facing the object to be processed is smaller than the thickness of the wall on the inner wall surface of the processing chamber in contact with the antenna chamber. Item 4. The plasma processing apparatus according to any one of Items 1 to 3 . 5. A processing area of the object to be processed is divided into a central area, an intermediate area surrounding the central area, and a peripheral area surrounding the intermediate area, and an intermediate area of the antenna chamber belonging to the orthographic area of the intermediate area. characterized in that to remotely located with respect to the target object than the high frequency antenna to the high frequency antenna is disposed in other regions of the antenna chamber disposed, any of claims 1 to 4 A plasma processing apparatus according to any one of the above. 6. The processing surface of the object to be processed is divided into a central region, an intermediate region surrounding the central region, and a peripheral region surrounding the intermediate region, and a wall of the antenna chamber facing the object to be processed is The plasma processing apparatus according to any one of claims 1 to 5 , wherein a wall portion belonging to the orthographic region of the intermediate region is configured to be thicker than a wall portion belonging to another region. 7. A side wall facing the object to be processed of said antenna chamber, characterized in that a process gas supply unit, the plasma processing apparatus according to any one of claims 1 to 6. 8. A wall on the side facing the object to be processed of said antenna chamber, characterized in that a coolant channel which refrigerant flows, the plasma treatment according to any one of claims 1 to 7 apparatus.