JP2001093839A - Plasma process system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma process system for surely preventing a deterioration of a sealing part such as an O-ring, and realizing continuous operation with high microwave power. SOLUTION: A plasma process system includes a processing chamber 2 for carrying out operation with a plasma, a microwave introducing means 3 for introducing the microwave into the treatment chamber 2, and a gas-feeding means 14 for feeding an reaction gas, which will be reacted with microwave in plasma state, to the processing chamber 2. In this case, the processing chamber 2 has an opening for introducing the microwave, and a microwave introducing window 4 made of a dielectric substance and inserted in the opening. Each sealing 10 or 11 between the inside and outside of the treatment chamber 2 is carried out on the side of the microwave introducing means 3.

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 a plasma processing apparatus used for manufacturing a semiconductor or a liquid crystal display.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view showing a schematic structure of a CVD apparatus as an example of a conventional plasma processing apparatus.

Referring to FIG. 8, in a process chamber 132, a wafer holder 137 holding a wafer 138 is provided so as to face the upper lid 131 of the process chamber 132. The inside of the process chamber 132 is held in a vacuum state using a vacuum pump or the like in advance. Process room 13
A waveguide 133 is connected to the upper lid 131, and the other end is connected to a magnetron (not shown), and microwaves generated by the magnetron are passed through a dielectric window 136 provided in an opening of the waveguide 133. To the process chamber 132. When a required source gas is supplied into the process chamber 132 through a gas introduction pipe 134 disposed above the process chamber 132, plasma is generated in the process chamber 132. As a result, film formation on the surface of the wafer 138 on the substrate holder 137 is performed.

The upper lid 131 of the process chamber 132 is provided with an opening 131b having a diameter larger than the inner diameter of the waveguide 133, and a dielectric window having a diameter slightly larger than the diameter of the opening 131b is provided on the opening 131b. 136 is provided concentrically via an O-ring 140 for sealing the vacuum state of the process chamber 132. The upper surface of the upper lid 131 of the process chamber 132 is
Dielectric window 136 with a slight gap surrounding it
And a flange 135 having the same outer diameter as the outer diameter thereof is mounted on the protruding portion 131a. The flange 135 is an open end of the waveguide 133. Connected concentrically to the part.

[0005] The O-ring 140 for sealing the vacuum state in the process chamber 132 has a problem that the temperature rises due to the heat generated by the plasma, so that the O-ring 140 gradually deteriorates and breaks down in vacuum. Furthermore, the deterioration of this O-ring
Although it does not proceed in a low microwave power region of 1 kW or less, it advances rapidly when microwave power of several kW is introduced, and the O-ring becomes unusable in a few minutes.

As a method for solving this problem, Japanese Patent No.
No. 625756. This will be described below with reference to FIG.

FIG. 9 is a cross-sectional view showing the vicinity of a connection between a waveguide and a process chamber in a plasma processing apparatus.

Referring to FIG. 9, in this plasma processing apparatus, a cooling water passage 102a is provided inside a peripheral portion of opening 102b of upper lid 102 of process chamber 132, that is, a portion located below O-ring 140. I have. Further, the cooling water passage 101 wider than the cooling water passage 102a is also provided at a position from the distal end surface of the protruding portion 101a of the flange 101.
b is provided inside in a circular shape. Further, the sheet 103 is sandwiched between the donut plate-shaped tip surface of the protruding portion 101a and the peripheral portion of the upper surface of the dielectric window 136 in close contact with each other.

During operation, cooling water passages 101b and 102
Cooling water is supplied to and flows through the cooling water passage a, so that the peripheral portions of the cooling water passages 101b and 102a are cooled.

[0010]

However, in the configuration of Japanese Patent No. 2625756 shown in FIG.
0 is located below the waveguide opening, so that the O-ring 1
40 is directly exposed to microwaves emitted from the waveguide. O-ring 1 by direct exposure to microwave
40 has the problem of deteriorating and causing vacuum breakdown. Further, the deterioration of the O-ring does not progress in a low microwave power region, but progresses rapidly when a microwave power of several times is introduced. In particular, the upper lid 102 and the dielectric window 13
When a discharge occurs in the gap between the O-ring and the O-ring, the O-ring rapidly deteriorates.

In this plasma process apparatus, the O-ring 140 is cooled by flowing cooling water through the cooling water passages 101b and 102a.
The installation position of the ring is close to the plasma generating unit, and it is necessary to sufficiently cool the O-ring 140 in order to maintain the performance of the O-ring 140. However, especially the cooling channel 1
01b, the cooling of the O-ring 140
Through the cooling water passage 101b.
The cooling efficiency of the ring 140 is poor.

Further, the O-ring 14 is connected to the cooling water passage 102a.
0 is cooled because its surroundings are also cooled.
D or etching process, the cooling water channel 102a
There is a problem that a large amount of reaction product is deposited on the inner wall of the process chamber in the peripheral portion. In addition, in order to provide the cooling water passage 102a having a high cooling efficiency in the immediate vicinity of the O-ring 140, there is a problem that a manufacturing cost is required.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a plasma processing apparatus that reliably prevents deterioration of a sealing portion such as an O-ring and enables continuous operation at high microwave power.

[0014]

A plasma processing apparatus according to the present invention has a processing chamber for performing processing using plasma, microwave introducing means for introducing microwaves into the processing chamber, and a plasma state by the microwaves. Gas supply means for supplying a reaction gas to the processing chamber, the processing chamber has an opening for introducing microwaves, and further includes a microwave introduction window made of a dielectric inserted into the opening, It is characterized in that the sealing between the inside and the outside of the chamber is performed on the microwave introducing means side.

Preferably, the microwave introduction means includes a microwave waveguide, and a sealing portion is provided at a joint between the microwave waveguide and the processing chamber and a joint between the microwave waveguide and the microwave introduction window. Should be provided.

According to the present invention, the sealing portion such as the O-ring can be provided at a position away from the plasma generating portion, which is not directly exposed to the microwave. Therefore, it is possible to prevent deterioration of the sealing portion such as the O-ring due to microwave exposure and heat from the plasma, thereby enabling continuous operation at high microwave power.

Preferably, a heat retaining medium flow path is provided in the vicinity of the sealing portions provided at the junction between the microwave waveguide and the processing chamber and the junction between the microwave waveguide and the microwave introduction window. It is better to further prepare.

With such a configuration, the sealing portion such as an O-ring and its peripheral portion can be maintained at a predetermined temperature. Therefore, the deterioration of the O-ring due to heat is reliably prevented,
Continuous operation at high microwave power can be enabled.

Preferably, fins for heat radiation are formed in the microwave waveguide. With such a configuration,
The sealing portion such as an O-ring and its peripheral portion can be kept at a predetermined temperature. Therefore, deterioration of the O-ring due to heat can be reliably prevented, and continuous operation at high microwave power can be performed.

Preferably, copper or aluminum is used as the material of the microwave waveguide.

According to the present invention, a material having high thermal conductivity such as copper or aluminum is used for the waveguide. Therefore, the effect of the heat retaining medium flow path or the heat dissipating fins can be enhanced, the O-ring and its peripheral portion can be maintained at a predetermined temperature, and the sealing portion such as the O-ring can be reliably prevented from deteriorating due to heat. Continuous operation at microwave power can be enabled.

Preferably, a step is provided at the junction between the microwave waveguide and the processing chamber, and the microwave waveguide and the processing chamber are brought into contact with each other at the step to conduct the electricity.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS.

FIGS. 1 and 2 are cross-sectional views showing the structure of an example of a plasma processing apparatus according to the present invention, and show cross sections in a short side direction and a long side direction plane of a waveguide, respectively.

Referring to FIGS. 1 and 2, the plasma processing apparatus according to the first embodiment includes a process chamber main body 2, a chamber lid 1, and a waveguide.

A dielectric 5 is attached to the surface of the chamber lid 1 on the side of the process chamber main body 2 by a dielectric holding member 6. In the process chamber main body 2, a substrate holder 7 holding a substrate 8 is placed facing the dielectric 5 on the surface of the chamber lid 1. At the center of the chamber lid 1, there is a slit-shaped opening, into which a microwave introduction window 4 having an inverted convex cross section is inserted. A waveguide end 3 is disposed above the chamber lid 1 so as to cover a gap between the opening of the chamber lid 1 and the microwave introduction window 4.

FIG. 3 is a plan view showing the shape of the joint surface of the waveguide end 3 with the chamber cover 1 and the microwave introduction window 4.

Referring to FIG. 3, an opening 3a for radiating microwaves into the process chamber body 2 through the microwave introduction window 4 is provided at the center of the waveguide end 3.
An O-ring groove 3b for an O-ring 11 for sealing with the microwave introduction window 4 outside the opening 3a, and an O-ring groove for an O-ring 10 for sealing with the chamber lid 1 outside the opening 3a. 3c is provided. Thus, the O-ring groove 3
O-ring grooves 3b and 3c are provided so that a gap 15 between the chamber lid 1 and the microwave introduction window 4 is located between the b and the O-ring groove 3c. Thus, the inside of the process chamber main body 2 is evacuated by a vacuum pump (not shown), and can be kept in a vacuum state.

O-ring grooves 3b and 3c in waveguide end 3
A heat retaining channel 12 is provided in the vicinity, and a medium flows so that the peripheral portion thereof is maintained at a predetermined temperature. This heat retaining channel 12 can be easily formed by using a gun drill or the like.

A waveguide 13 whose other end is connected to a magnetron (not shown) is connected to the upper portion of the waveguide end 3. The microwave emitted from the magnetron is guided from the waveguide 13 to the waveguide end 3, and from the opening 3 a of the waveguide end 3 via the dielectric window 4 and the dielectric 5, to the process chamber. Radiated into the body 2.

A reaction gas inlet 14 for introducing a reaction gas into the process chamber body 2 is provided on a side surface of the process chamber body 2.

Next, the operation when the plasma processing apparatus according to the first embodiment thus configured is used as a CVD apparatus will be described.

The inside of the process chamber body 2 is held in a vacuum state by a vacuum pump (not shown). Microwaves emitted by a magnetron (not shown) are radiated through the waveguide 13 from the opening 3 a of the waveguide end 3 toward the process chamber body 2. The microwave introduction window 4 made of a dielectric and the dielectric 5 pass microwaves.
The microwave radiated from the opening 3a is guided into the process chamber main body 2.

Before introducing the microwave into the process chamber body 2, a required source gas is supplied to the process chamber body 2.
The gas is supplied into the process chamber main body 2 from the reaction gas introduction unit 14 arranged at the upper part of the side surface, and has a predetermined gas pressure. When the microwave is guided into the process chamber main body 2, plasma is generated in the process chamber main body 2. Thereby, the substrate 8 on the substrate holder 7 is
A thin film of a desired material is deposited on the surface.

During this process, due to the heat generated by the generation of the plasma, the dielectric 5 placed immediately adjacent thereto is heated and its temperature rises. The heat is transferred to the dielectric 5
From the microwave introduction window 4, the chamber lid 1, and further to the waveguide end 3, and the respective temperatures rise. However, the heat retaining medium is supplied to the heat retaining channel 12 of the waveguide end 3 from an end (not shown) and flows therethrough. At this time, the heat retaining flow path 12 is controlled so that the peripheral portion of the heat retaining flow path 12 has a predetermined temperature.
The amount of heat and the temperature of the heat retaining medium flowing through are determined. As a result, the O-ring 10 located below the heat retaining channel 12
And 11, the microwave introduction window 4 and the chamber lid 1 with which the waveguide end 3 is in contact are maintained at a predetermined temperature.

By actively controlling the flow rate and temperature of the heat retaining medium flowing through the heat retaining flow path 12, even if the input power and the like are changed and the heat generated from the plasma is changed, the temperature of each component is maintained at a predetermined value. Can be maintained.

By using a material having high thermal conductivity, such as copper or aluminum, as the material of the waveguide end portion 3, the speed of the heat conduction is increased, and the temperature can be quickly maintained.

In the plasma processing apparatus according to the first embodiment of the present invention configured as described above, the O-rings 10 and 11 are located on the opening 3a side of the waveguide end 3, and are directly exposed to microwaves. Not done. Therefore, deterioration of the O-ring due to exposure to microwaves can be prevented. Also,
The temperature of the peripheral portion can be maintained at a predetermined temperature by the heat retaining channel 12 at the waveguide end 3. Further, the O-rings 10 and 11 are provided at positions away from the plasma generating unit. As a result, the O-rings 10 and 11 do not deteriorate and no reaction product is deposited on the inner wall of the process chamber.

(Embodiment 2) A second embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a sectional view showing another example of the plasma processing apparatus according to the present invention. The difference from the first embodiment lies in the shape of the waveguide end 3, and the same reference numerals as in FIGS. 1 to 3 denote the same parts, and a description thereof will be omitted.

Referring to FIG. 4, in this plasma processing apparatus, a plurality of fins 3d are provided on the outer peripheral portion of waveguide end portion 3.

The heat generated by the plasma generation is transmitted to the waveguide end 3 via the dielectric 5, the microwave introduction window 4, and the chamber lid 1. Then, the heat is radiated to the atmosphere from the fins 3d provided at the waveguide end 3. The shape and the number of the fins 3d are designed so that the temperature near the O-ring grooves 3b and 3c of the waveguide end portion 3 becomes a predetermined temperature.

By using a material having a high thermal conductivity, such as copper or aluminum, as the material of the waveguide end portion 3, the heat radiation performance can be further improved.

In the second embodiment, no heat retaining channel is provided. Needless to say, the provision of the heat retaining channel further enhances the heat retaining effect.

In the plasma processing apparatus according to the second embodiment configured as described above, the O-rings 10 and 1
1 is on the side of the opening 3a of the waveguide end 3 and is not directly exposed to microwaves. Therefore, deterioration of the O-ring due to exposure to microwaves can be prevented. Also, by providing the plurality of fins 3d at the waveguide end 3, the peripheral portions of the O-ring grooves 3b and 3c can be maintained at a predetermined temperature. Further, the O-rings 10 and 11 are provided at positions away from the plasma processing apparatus. As a result, the O-rings 10 and 11 do not deteriorate and no reaction product is deposited on the inner wall of the process chamber.

(Embodiment 3) A third embodiment of the present invention will be described with reference to FIG.

FIG. 5 is a sectional view showing still another example of the plasma processing apparatus according to the present invention.

The difference from the first and second embodiments is the method of introducing the raw material gas. The same reference numerals are given to those substantially the same as those shown in FIGS. 1 to 4, and the description thereof will be omitted.

In the third embodiment, the source gas is introduced uniformly from the chamber lid 1 side.

Referring to FIG. 5, a gas supply pipe 21 for supplying a source gas from the atmosphere side into process chamber 2 is provided in chamber lid 1, and is provided on the surface of chamber lid 1 on the side of process chamber body 2. Connected to the gas passage 1d. Also, the dielectric plate having a large number of discharge ports 20a that blow out uniformly into the source gas process chamber main body 2 in a shower shape is made of a dielectric so that the surface of the process chamber main body 2 of the chamber lid 1 is covered. It is fixed by the holding member 6.

The microwave is emitted from the opening 3a of the waveguide end 3 and the raw material gas is
By supplying from the 0 discharge port 20a, uniform plasma is generated. Thus, a uniform film is formed on the surface of the substrate 8.

(Embodiment 4) A fourth embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a sectional view showing still another example of the plasma processing apparatus according to the present invention.

The difference from the first to third embodiments is that a plurality of microwave introduction parts are provided. The same reference numerals are given to the same parts as those shown in FIGS. Omitted.

When a large-sized liquid crystal display element is manufactured, a plasma processing apparatus capable of performing a uniform treatment over a large area is required. By providing a plurality of common microwave introduction units in parallel, a large-area uniform plasma can be realized.

Referring to FIG. 6, by providing two sets of microwave introduction parts 60 in the plasma processing apparatus shown in FIG. 5 described in the third embodiment in parallel, the area is about twice as large as one set. Can be subjected to plasma processing.

(Fifth Embodiment) A fifth embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a sectional view showing still another example of the plasma processing apparatus according to the present invention.

What is different from the first to fourth embodiments is the sealing portion between the processing chamber and the outside. The same reference numerals are given to those substantially the same as those in FIGS. 1 to 5, and the description thereof will be omitted.

Referring to FIG. 7, the cross-sectional shape of the connecting portion of waveguide end 3 with chamber lid 1 and microwave introduction window 4 is concave, and a step 3d is formed between O-ring grooves 3b and 3c. Is provided. The chamber lid 1 side has a convex cross section, and a step portion 1e is provided outside the opening into which the microwave introduction window 4 is inserted. The step 3d and the step 1e are fitted together, and the position of the waveguide end 3 with respect to the chamber lid 1 is accurately determined. As a result, the microwave can be introduced into the microwave introduction window 4 without bias.

Further, the respective wall surfaces come into contact with each other, and conduction between the chamber lid 1 and the waveguide end 3 is established at a position near the microwave introduction window 4, and a gap between the chamber lid 1 and the waveguide end 3 is formed. Microwave leakage can be eliminated.

In this embodiment, the chamber cover 1
Although the case where the side is a convex shape and the waveguide end 3 side is a concave shape is shown, the reverse case can be implemented without any problem.

In the first to fifth embodiments described above, the configuration in which the plasma processing apparatus of the present invention is applied to a CVD apparatus has been described. However, the present invention is not limited to this. For example, the present invention can be applied to an etching apparatus. Needless to say.

[0065]

As described above, in the plasma processing apparatus according to the present invention, the sealing portion such as the O-ring is provided on the opening side of the waveguide, and is not directly exposed to the microwave. Further, by disposing a sealing portion such as an O-ring on the opening side of the waveguide, the sealing portion can be kept away from the plasma generating portion.

Further, by keeping warm water flowing through the heat retaining channel at the end of the waveguide, or by providing a plurality of fins at the end of the waveguide,
The periphery of the sealing portion such as an O-ring can be kept at a predetermined temperature.

As described above, according to the present invention, since the temperature rise of the sealing portion formed of a heat-sensitive material such as an O-ring can be controlled, deterioration of these members due to heat can be reliably prevented. The microwave power can be set low.
Further, unnecessary reaction products do not precipitate on the inner wall of the process chamber.

[Brief description of the drawings]

FIG. 1 is a sectional view of a plasma processing apparatus according to a first embodiment in a short side direction of a waveguide.

FIG. 2 is a cross-sectional view of the plasma processing apparatus according to the first embodiment in a long side direction of the waveguide.

FIG. 3 is a plan view illustrating a waveguide sealing portion of the plasma processing apparatus according to the first embodiment.

FIG. 4 is a cross-sectional view illustrating a main part of a plasma processing apparatus according to a second embodiment.

FIG. 5 is a sectional view showing a plasma processing apparatus according to a third embodiment.

FIG. 6 is a sectional view showing a plasma processing apparatus according to a fourth embodiment.

FIG. 7 is a sectional view showing a plasma processing apparatus according to a fifth embodiment.

FIG. 8 is a cross-sectional view illustrating a structure of an example of a conventional plasma processing apparatus.

FIG. 9 is a cross-sectional view showing a structure of a main part of a plasma processing apparatus disclosed in Japanese Patent No. 2625756.

[Explanation of symbols]

Reference Signs List 1 chamber lid, 1e stepped portion, 2 process chamber body, 3 waveguide end, 3a waveguide opening, 3b inner O-ring groove, 3c outer O-ring groove, 3d stepped portion, 4 microwave introduction window 5, dielectric, 6 dielectric holding member, 7 substrate holder, 8 substrate, 9 O-ring between chamber lid and process chamber main body, 10 O-ring between chamber lid and waveguide end main body, 11 O-ring between microwave introduction window and waveguide end, 12 heat retaining channel, 13 waveguide, 14 reaction gas inlet, 101
Flange, 102 upper lid, 103 sheet, 131 upper lid, 132 process chamber, 133 waveguide, 134 gas introduction pipe, 135 flange, 136 dielectric window, 13
7 Wafer holder, 138 wafer, 140 O-ring.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Hirayama 05 Aoba Aramaki Aoba-ku, Aoba-ku, Sendai City, Miyagi Prefecture Within the Graduate School of Engineering, Tohoku University (72) Inventor Tadahiro Omi 2 Yonegabukuro, Aoba-ku, Sendai City, Miyagi Prefecture −1-17− 301 F term (reference) 4K030 FA01 KA26 KA30 KA46 5F004 AA16 BA20 BC01 5F045 AA09 DP02 EB02 EH03 EJ01 EJ09

Claims (6)

[Claims] 1. A plasma processing apparatus, comprising: a processing chamber for performing a process using plasma; a microwave introduction unit for introducing a microwave into the processing chamber; and a reaction gas that is brought into a plasma state by the microwave. Gas supply means for supplying to the processing chamber, the processing chamber has an opening for introducing a microwave, further comprising a microwave introduction window made of a dielectric inserted into the opening, The sealing between the inside and the outside of the processing chamber is performed on the side of the microwave introduction unit, wherein the plasma processing apparatus is characterized in that the sealing is performed. 2. The microwave introduction means includes a microwave waveguide, and is provided at a junction between the microwave waveguide and the processing chamber and a junction between the microwave waveguide and the microwave introduction window. The plasma processing apparatus according to claim 1, wherein a sealing portion is provided. 3. A heat insulator is provided at a junction between the microwave waveguide and the processing chamber and at a junction between the microwave waveguide and the microwave introduction window in the vicinity of the sealing portions provided respectively. The plasma processing apparatus according to claim 2, further comprising a medium passage for use. 4. The plasma processing apparatus according to claim 2, wherein fins for heat radiation are formed in the microwave waveguide. 5. The plasma processing apparatus according to claim 2, wherein copper or aluminum is used as a material of the microwave waveguide. 6. A step portion is provided at a joining portion between the microwave waveguide and the processing chamber, and the microwave waveguide and the processing chamber are brought into contact with each other at the step portion to conduct electricity. The plasma processing apparatus according to claim 2, wherein: