JP2004055895A - Inductively coupled plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inductively coupled plasma processing apparatus that can suppress deflection of a partition structure partitioning a treatment chamber, including a dielectric wall and an antenna chamber from each other, without making the support portion of the dielectric wall larger in size nor making the dielectric wall larger in thickness. <P>SOLUTION: This inductively coupled plasma processing apparatus comprises the treatment chamber 4 in which plasma processing is performed on a substrate G, a process gas supply system 20 which supplies process gas into the processing chamber 4, and an exhaust system 30, which exhausts the gas in the chamber 4. This device also comprises the dielectric wall 2, constituting the top wall of the treatment chamber 4, a high-frequency antenna 15 provided above the wall 2, and the antenna chamber 3 which is provided above the treatment chamber 4 and houses the antenna 15 and the bottom wall of which is formed of the dielectric wall 2 and vertical walls 5, which divide the antenna chamber 3 into a plurality of small chambers 6 and supported by the sidewalls 3a of the chamber 3. The dielectric wall 2 is split into a plurality of pieces, corresponding to the small chambers 6, and each split piece 2a of the wall 2 is supported by the sidewalls 3a of the antenna chamber 3 and vertical walls 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inductively coupled plasma processing apparatus for performing plasma processing such as dry etching on a substrate to be processed such as a liquid crystal display (LCD) substrate by inductively coupled plasma.
[0002]
[Prior art]
For example, in an LCD manufacturing process, plasma processing such as etching, sputtering, and CVD (chemical vapor deposition) is frequently used for an LCD glass substrate as a substrate to be processed.
[0003]
Various types of plasma processing apparatuses are used for performing such plasma processing. Among them, an inductively coupled plasma (ICP) processing apparatus is known as a type capable of generating high-density plasma. Have been.
[0004]
In an inductively coupled plasma processing apparatus, typically, a ceiling of a processing chamber for performing plasma processing that can be maintained in a vacuum is formed of a dielectric wall, and a radio frequency (RF) antenna is disposed thereon. When high-frequency power is supplied to the high-frequency antenna, an induction electric field is formed in the processing chamber, and the processing gas introduced into the processing chamber is turned into plasma by the induction electric field. Plasma processing such as etching is performed by the plasma.
[0005]
By the way, in the LCD manufacturing process, the LCD glass substrate, which is the substrate to be processed, has such dimensions that one or more LCD panel products can be obtained. Recently, from the viewpoint of improving throughput, there is a strong demand for a large LCD glass substrate, and a large LCD glass substrate having a side of more than 1 m is demanded. Also has to be enlarged. When the dielectric wall becomes large in this way, it is necessary to increase its thickness in order to maintain sufficient strength to withstand the pressure difference between the inside and outside of the processing chamber and its own weight. Since the distance between the high-frequency antenna and the plasma region increases, the energy efficiency decreases and the plasma density decreases. Further, when the thickness of the dielectric wall is increased as described above, the dielectric wall becomes extremely expensive.
[0006]
As a technique for avoiding such a situation, a technique disclosed in JP-A-2001-28299 has been proposed. In this technology, a main body container of an inductively coupled plasma processing apparatus is divided into an upper antenna chamber and a lower processing chamber by a partition structure, and the partition structure includes a dielectric wall, and the dielectric wall has a cross shape. A structure is employed in which the support beam is supported by a support beam and the support beam is suspended by a suspender fixed to the ceiling of the antenna room. Thus, the load on the dielectric wall is significantly reduced, so that the dielectric wall can be made thin.
[0007]
[Problems to be solved by the invention]
However, in the technique disclosed in Japanese Patent Application Laid-Open No. 2001-28299, the support beam supports the dielectric wall, and the support beam is suspended by the suspender. Therefore, the support beam that is a part of the partition structure is not bent. As described above, it is necessary to increase the width of the support beam. However, if the width of the support beam is increased, the effective area of the dielectric wall is reduced, and the energy efficiency is reduced.
[0008]
The present invention has been made in view of such circumstances, and does not increase the size of the supporting portion of the dielectric wall and does not increase the thickness of the dielectric wall. It is an object of the present invention to provide an inductively-coupled plasma processing apparatus capable of suppressing the deflection of a partition structure for partitioning between them.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a processing chamber that is kept airtight and performs a plasma process on a substrate to be processed, a processing gas supply system that supplies a processing gas into the processing chamber, and exhausting the processing chamber. An exhaust system for reducing the pressure in the processing chamber, a dielectric wall forming an upper wall of the processing chamber, and a high-frequency power supplied to the dielectric chamber to guide the processing chamber into the processing chamber. A high-frequency antenna for forming an electric field, provided above the processing chamber, a bottom wall is formed by the dielectric wall, an antenna chamber for housing the high-frequency antenna, and the antenna chamber is partitioned into a plurality of small chambers; A vertical wall supported on a side wall of the antenna chamber, wherein the dielectric wall is divided into a plurality of sections corresponding to the plurality of small chambers, and each divided piece of the dielectric wall is With said vertical wall Providing an inductively coupled plasma processing apparatus characterized in that it is supported.
[0010]
According to the present invention, the antenna chamber whose bottom wall is formed by the dielectric wall is divided into a plurality of small chambers by the vertical wall supported by the side wall of the antenna chamber, and the dielectric wall is divided into a plurality of pieces corresponding to the plurality of small chambers. And each of the divided pieces of the dielectric wall is supported by the side wall of the antenna chamber and the vertical wall, and the supporting element is a vertical wall, so that the supporting portion of the dielectric wall is widened. It is possible to prevent bending of the partition structure including the dielectric wall and partitioning between the processing chamber and the antenna chamber without increasing the thickness of the dielectric wall.
[0011]
In the present invention, the high-frequency antenna may have a structure having a plurality of antenna pieces respectively housed in the plurality of small chambers, and high-frequency power may be supplied from one high-frequency power supply to the high-frequency antenna, A plurality of high-frequency antennas may be provided corresponding to the plurality of small chambers, and a plurality of high-frequency power supplies for supplying high-frequency power to each of the plurality of high-frequency antennas may be provided.
[0012]
Further, as a typical example, the vertical wall partitions the antenna chamber into a cross and divides the antenna chamber into four small chambers.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a vertical sectional view showing an inductively coupled plasma etching apparatus according to one embodiment of the present invention, and FIG. 2 is a horizontal sectional view showing an antenna chamber thereof. This apparatus is used for etching a metal film, an ITO film, an oxide film and the like, for example, when forming a thin film transistor on an LCD glass substrate in the manufacture of LCD.
[0014]
The plasma etching apparatus has an airtight main body container 1 in the form of a rectangular tube made of a conductive material, for example, aluminum or an aluminum alloy whose inner wall surface is anodized. The main body container 1 is assembled so as to be disassembled, and is grounded by a ground wire 1a. The main body container 1 is vertically divided into an antenna chamber 3 and a processing chamber 4 by a dielectric wall 2. Therefore, the dielectric wall 2 forms a ceiling wall of the processing chamber 4. The dielectric wall 2 is made of ceramic such as Al ₂ O ₃ , quartz, or the like.
[0015]
In the antenna chamber 3 of the main body container 1, two vertical walls 5 are provided so as to form a cross so as to be supported by two pairs of opposing side walls 3a, respectively. Therefore, the antenna chamber 3 is divided into four small chambers 6 by two vertical walls 5. A support shelf 7 is provided at the bottom of the side wall 3a and the vertical wall 5, and divided pieces 2a obtained by dividing the dielectric wall 2 into four pieces are placed on the support shelf 7 of each small chamber 6. A seal ring 8 is interposed between each of the divided pieces 2 a of the dielectric wall 2 and the support shelf 7 to be hermetically sealed, and these are fixed by bolts 9. The vertical wall 5 is made of, for example, aluminum or an aluminum alloy whose surface is anodized similarly to the main container 1.
[0016]
A gas inlet 11 is formed at the center of the top wall 3b of the antenna room 3. As shown in FIG. 3, a gas flow path 12 extending from the upper end of the intersection 5a where the two vertical walls 5 intersect with the gas inlet 11 extends downward. The gas flow path 12 includes a horizontal flow path 12a extending horizontally and crosswise along a vertical wall below the intersection 5a, and a plurality of vertical flow paths 12b extending downward from the cross-shaped horizontal flow path 12a. And a gas discharge port 13 is formed at the bottom of the vertical wall 5. Therefore, the plurality of gas discharge ports 13 are arranged in a cross shape, from which a predetermined processing gas is discharged in a shower shape.
[0017]
On the other hand, the gas inlet 11 is provided with a gas supply pipe 14 so as to communicate with the gas flow path 12. The gas supply pipe 14 penetrates from the ceiling of the main body container 1 to the outside, and is connected to a processing gas supply system 20 including a processing gas supply source and a valve system. Therefore, in the plasma etching, the processing gas supplied from the processing gas supply system 20 is supplied to the gas flow channel 12 through the gas supply pipe 14, and further passes through the horizontal flow channel 12a and the vertical flow channel 12b. Is discharged into the processing chamber 4 from a gas discharge port 13 provided at the bottom of the processing chamber 4, and is used for etching a predetermined film formed on the LCD glass substrate G disposed in the processing chamber 4.
[0018]
A high-frequency antenna 15 is provided in the antenna room 3. Specifically, the high-frequency antenna 15 is divided into four antenna pieces 15a, and these antenna pieces 15a are disposed in each small chamber 6 of the antenna chamber 3 so as to face the dielectric wall 2. . These antenna pieces 15a are formed of a planar coil antenna having a substantially rectangular spiral shape, and adjacent antenna pieces are wound with the antenna wires wound in opposite directions. One end of each of the antenna pieces 15a is connected to a feed rod 16 extending vertically upward from each of the small chambers 6 of the antenna chamber 3, the other end is connected to the main body container 1, and is grounded via the main body container 1. .
[0019]
On the top wall 3b of the antenna room 3, a matching device 17 for matching the impedance of the plasma to the high-frequency transmission line impedance is provided, and the upper end of each feed rod 16 is connected to the matching device 17. On the other hand, the matching unit 17 is provided with a high frequency power supply 18 for generating an induced electric field, for example, having a frequency of 13.56 MHz.
[0020]
During the plasma processing, high frequency power for generating an induced electric field, for example, having a frequency of 13.56 MHz, is supplied from the high frequency power supply 18 to the high frequency antenna 15. An induction electric field is formed in the processing chamber 4 by the high-frequency antenna 15 supplied with the high-frequency power in this way, and the induction electric field causes the processing gas supply system 20 to pass through the gas supply pipe 14 and the gas flow path 12 to the gas discharge port. The processing gas discharged from 13 is turned into plasma. At this time, the output of the high frequency power supply 18 is appropriately set so as to have a value sufficient to generate plasma.
[0021]
A susceptor 22 as a mounting table for mounting the LCD glass substrate G is provided below the processing chamber 4 so as to face the high-frequency antenna 15 with the dielectric wall 2 interposed therebetween. The susceptor 22 is made of a conductive material, for example, aluminum whose surface is anodized. The LCD glass substrate G placed on the susceptor 22 is sucked and held on the susceptor 22 by an electrostatic chuck (not shown).
[0022]
The susceptor 22 is housed in an insulator frame 24 and further supported by a hollow support 25. The column 25 penetrates through the bottom of the main body container 1 while maintaining an airtight state, and is supported by an elevating mechanism (not shown) provided outside the main body container 1. It is driven up and down. A bellows 26 is provided between the insulator frame 24 for accommodating the susceptor 22 and the bottom of the main body container 1 so as to hermetically surround the support column 25. Airtightness in the container 4 is guaranteed. The side wall 4a of the processing chamber 4 is provided with a loading / unloading port 27 for loading / unloading the substrate G, and the loading / unloading port 27 can be opened and closed by a gate valve 27a.
[0023]
A high-frequency power supply 29 is connected to the susceptor 22 via a matching unit 28 by a power supply rod 25 a provided in the hollow support 25. The high-frequency power supply 29 applies high-frequency power for bias, for example, high-frequency power having a frequency of 3.2 MHz to the susceptor 22 during the plasma processing. The ions in the plasma generated in the processing chamber 4 are effectively drawn into the substrate G by the high frequency power for bias.
[0024]
Further, in the susceptor 22, a temperature control mechanism including a heating means such as a ceramic heater, a coolant flow path, and the like, and a temperature sensor are provided in order to control the temperature of the substrate G (neither is shown). . The piping and wiring for these mechanisms and members are all led out of the main body container 1 through the hollow support 25.
[0025]
An exhaust mechanism 30 including a vacuum pump and the like is connected to the bottom of the processing chamber 4 via an exhaust pipe 31. The exhaust mechanism 30 exhausts the processing chamber 4 and maintains the inside of the processing chamber 4 at a predetermined level during plasma processing. It is set and maintained in a vacuum atmosphere (for example, 1.33 Pa).
[0026]
Next, a description will be given of a processing operation when plasma etching processing is performed on the LCD glass substrate G using the inductively coupled plasma etching apparatus configured as described above.
[0027]
First, with the gate valve 27a opened, the substrate G is loaded into the processing chamber 4 from the loading / unloading port 27 by a transport mechanism (not shown), and is placed on the loading surface of the susceptor 22, and then the electrostatic chuck ( The substrate G is fixed on the susceptor 22 by not shown). Next, the processing gas supplied from the processing gas supply system 20 into the processing chamber 4 is discharged into the processing chamber 4 from the gas discharge port 13 through the gas supply pipe 14 and the gas flow path 12, and exhausted by the exhaust mechanism 30. By evacuating the inside of the processing chamber 4 through the pipe 31, the inside of the processing chamber 4 is maintained at a pressure atmosphere of, for example, about 1.33 Pa.
[0028]
Next, a high frequency of 13.56 MHz from the high frequency power supply 18 is applied to each of the antenna pieces 15 a of the high frequency antenna 15 via the matching unit 17 and the power supply rod 16, whereby the uniform frequency is applied to the processing chamber 4 via the dielectric wall 2. Form an induced electric field. By the induction electric field formed in this way, the processing gas is turned into plasma in the processing chamber 4 and high-density inductively coupled plasma is generated. The ions in the plasma generated in this manner are effectively drawn into the substrate G by the high frequency power of 3.2 MHz applied to the susceptor 22 from the high frequency power supply 29, and the substrate G is uniformly etched. Is applied.
[0029]
In this case, two vertical walls 5 are provided so as to form a cross so as to be supported by two pairs of opposing side walls 3a of the antenna chamber 3 having a bottom wall formed by the dielectric wall 2, respectively. The antenna chamber 3 is partitioned into four small chambers by the wall 5 so that the dielectric wall 2 is divided into a plurality of small chambers corresponding to the plurality of small chambers, and each divided piece 2a of the dielectric wall 2 is connected to the side wall 3a of the antenna chamber 3. Since the supporting element is a vertical wall so as to be supported by the vertical wall 5, the dielectric wall 2 can be formed without widening the supporting portion of the dielectric wall 2 and without increasing the thickness of the dielectric wall 2. The bending of the partition structure that partitions between the processing chamber 4 and the antenna chamber 3 can be prevented.
[0030]
The present invention can be variously modified without being limited to the above embodiment. For example, in the above-described embodiment, power is supplied from one high-frequency power supply to each antenna piece 15a of the high-frequency antenna 15 disposed in each small chamber 6 via a matching device. However, as shown in FIG. May be provided with independent high-frequency antennas 15 ', and a plurality of matching devices 17' and high-frequency power supplies 18 'may be provided corresponding to each high-frequency antenna 15'.
[0031]
Further, in the above embodiment, the vertical walls are provided in a cross shape. However, as shown in FIG. 5, only one vertical wall 5 may be provided to divide the antenna chamber 3 into two, or FIG. As shown in FIG. 7, a plurality of vertical walls 5 may be arranged in parallel to divide the antenna chamber 3.
[0032]
Further, in the above embodiment, the case where the present invention is applied to the etching apparatus has been described. However, the present invention is not limited to the etching apparatus but can be applied to other plasma processing apparatuses such as sputtering and CVD film formation. Furthermore, although an LCD substrate is used as a substrate to be processed, the present invention is not limited to this, and can be applied to a case where another substrate such as a semiconductor wafer is processed.
[0033]
【The invention's effect】
As described above, according to the present invention, the antenna chamber in which the bottom wall is formed by the dielectric wall is divided into a plurality of small chambers by the vertical wall supported by the side wall of the antenna chamber, and the dielectric wall is divided into the plurality of small chambers. Correspondingly, it is divided into a plurality, and each of the divided pieces of the dielectric wall is supported by the side wall of the antenna chamber and the vertical wall, so that the supporting element is a vertical wall. Without increasing the width of the supporting portion and without increasing the thickness of the dielectric wall, it is possible to prevent the partition structure including the dielectric wall from separating between the processing chamber and the antenna chamber from bending.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing an inductively coupled plasma etching apparatus according to one embodiment of the present invention.
FIG. 2 is a horizontal sectional view showing an antenna chamber of the inductively coupled plasma etching apparatus of FIG. 1;
FIG. 3 is a perspective view showing a vertical wall of the inductively coupled plasma etching apparatus of FIG. 1;
FIG. 4 is a schematic perspective view showing an antenna part of an inductively coupled plasma etching apparatus according to another embodiment of the present invention.
FIG. 5 is a horizontal cross-sectional view showing another example of a state where the antenna chamber is partitioned by vertical walls.
FIG. 6 is a horizontal cross-sectional view showing still another example of a state where the antenna chamber is partitioned by vertical walls.
[Explanation of symbols]
1; main body container 2; dielectric wall 2a; divided piece 3; antenna chamber 3a; side wall 4; processing chamber 5; vertical wall 5a; intersection 6; small chamber 7; support shelf 11; Gas discharge port 14, gas supply pipes 15, 15 '; high-frequency antenna 15a; antenna piece 18; high-frequency power supply 20; processing gas supply system 22; susceptor 30;

Claims (4)

A processing chamber that is kept airtight and performs plasma processing on the substrate to be processed;
A processing gas supply system for supplying a processing gas into the processing chamber,
An exhaust system that exhausts the processing chamber and brings the processing chamber into a reduced pressure state;
A dielectric wall constituting an upper wall of the processing chamber;
A high-frequency antenna that is provided above the dielectric wall and that forms an induction electric field in the processing chamber by being supplied with high-frequency power;
An antenna chamber provided above the processing chamber, a bottom wall formed by the dielectric wall, and accommodating the high-frequency antenna;
Partitioning the antenna chamber into a plurality of small chambers, comprising a vertical wall supported on a side wall of the antenna chamber;
The dielectric wall is divided into a plurality of parts corresponding to the plurality of small chambers, and each divided piece of the dielectric wall is supported by a side wall of the antenna chamber and the vertical wall. Processing equipment. The inductive coupling according to claim 1, wherein the high-frequency antenna has a plurality of antenna pieces housed in the plurality of small chambers, respectively, and high-frequency power is supplied to the high-frequency antenna from one high-frequency power supply. Plasma processing equipment. 2. The inductively coupled plasma processing according to claim 1, wherein the high-frequency antenna has a plurality of high-frequency power supplies for supplying high-frequency power to the plurality of high-frequency antennas, respectively. 3. apparatus. The inductively coupled plasma processing apparatus according to any one of claims 1 to 3, wherein the vertical wall partitions the antenna chamber into a cross and divides the antenna chamber into four small chambers.

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