JPH0525646A - Microwave plasma device - Google Patents

Abstract

PURPOSE:To simplify the administration of a refrigerant and to eliminate the need for an insulation refrigerant between excitation coils as well as to reduce the size of the coils by forming water paths within the frame body part of the coils and cooling the coils without bringing the refrigerant into direct contact with the coils. CONSTITUTION:The microwave plasma device is constituted by providing a microwave guide tube 15, a plasma forming chamber 11, a reaction chamber 17, etc., and disposing the excitation coils 30 around the plasma forming chamber 11. The excitation coils 30 are constituted of the frame body parts 33 formed internally with the water paths 36, plural pieces of winding frame bodies 34 extended at prescribed intervals in the direction approximately orthogonal with the axial direction from the frame body parts 33, and the coils 35 interposed between the winding frame bodies 34. The coils 35 are efficiently cooled in this way without bringing the refrigerant into direct contact therewith. The small-sized excitation coils 30 having the reliable cooling function are thus easily produced, by which the performance of the microwave plasma device is improved.

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to a microwave plasma apparatus, mainly and more particularly a semiconductor CVD in the manufacturing process (Ch emical Va pour De position) apparatus, a microwave plasma apparatus used as an etching apparatus or the like.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view schematically showing an example of a conventional microwave plasma apparatus, and 11 in the figure shows a plasma generation chamber. The plasma generating chamber 11 has a cylindrical peripheral wall 11b in which a cooling water passage 11a is formed.
The upper wall 11c and the lower wall 11d are partitioned from each other, and the microwave introduction port 12 is formed in the approximate center of the upper wall 11c. Microwave inlet 12
Is sealed by a quartz glass 14 disposed above it, and one end of a microwave waveguide 15 is connected to the microwave introduction port 12 via the quartz glass 14. The other end of the microwave waveguide 15 is connected to a microwave oscillator (not shown), and the microwave generated by the microwave oscillator is introduced into the plasma generation chamber 11 via the microwave waveguide 15 and the quartz glass 14. It is supposed to be done. Further, a gas supply system 16 is connected to the upper wall 11c, and an exciting coil 18 is concentrically arranged around the plasma generating chamber 11 and the microwave waveguide 15 around one end thereof. .. The exciting coil 18 is connected to a DC power source (not shown),
When DC power is supplied, a magnetic field is formed in the plasma generation chamber 11 so that plasma is generated by the introduction of microwaves. Along with this, the exciting coil 18 forms a divergent magnetic field whose magnetic flux density decreases toward the reaction chamber 17 described later, and the plasma generated in the plasma generation chamber 11 by the divergent magnetic field is introduced into the reaction chamber 17. It is like this.

On the other hand, the microwave inlet 1 of the lower wall 11d
A plasma extraction window 13 is formed at a position facing 2 and a reaction chamber 17 which is a sample chamber is provided so as to face the plasma extraction window 13. A sample table 19 for mounting the sample S is arranged at a position facing the plasma extraction window 13 in the reaction chamber 17.
An electrode 22 for electrostatically adsorbing the sample S and applying a bias is embedded therein. An RF (radio high frequency) power source 24, which is a high frequency power source, is connected to the electrode 22 via a bonder 23. Further reaction chamber 17
An exhaust port 20 connected to an exhaust device (not shown) is opened in a lower wall of the reaction chamber 17, and a gas supply system 21 for supplying a required reaction gas into the reaction chamber 17 is provided on one side wall of the reaction chamber 17. Are connected.

When the surface of the sample S placed on the sample table 19 is etched by using the microwave plasma device thus constructed, first, the plasma generation chamber 11 and the reaction chamber are set to a required degree of vacuum. A reaction gas is supplied from the gas supply systems 16 and 21 into the space 17. Next, a voltage is applied to the exciting coil 18 to form a divergent magnetic field in the plasma generation chamber 11, and a microwave is introduced into the plasma generation chamber 11 from the microwave introduction port 12 to apply a high frequency electric field. Then, plasma is generated in the plasma generation chamber 11, and the generated plasma is guided from the plasma generation chamber 11 to the periphery of the sample S in the reaction chamber 17 through the plasma extraction window 13 by the divergent magnetic field. And on the surface of the sample S,
A surface reaction occurs due to the ions and radical particles in the plasma flow, which causes the surface of the sample S to be etched.

[0005]

By the way, when a magnetic field is formed in the plasma generation chamber 11, the exciting coil 18 heats up considerably as a voltage is applied. Therefore, conventionally, for example, the following two methods have been adopted to cool the exciting coil 18 which generates heat when a voltage is applied. One is a method in which the coil wire of the exciting coil 18 is immersed in a refrigerant in a hermetically sealed container in which the refrigerant is sealed, and the refrigerant in the hermetically sealed container is circulated, and the other is a round pipe or a square pipe having a refrigerant passage. This is a method of forming the exciting coil 18 with the wire.

However, in the former method, since the refrigerant and the coil are in direct contact with each other, it is necessary to use an insulating refrigerant such as Freon, and in this case, a dedicated refrigerant for circulating the insulating refrigerant is used. A pump was needed. Further, since an insulating refrigerant such as Freon easily evaporates, it takes a lot of time to maintain the circulation pressure, which causes various problems in terms of refrigerant management. Furthermore, the former method requires a complicated work of arranging the coil in the container and sealing it.
At this time, the refrigerant may leak if the airtight seal is not completely performed. Further, since the whole coil surrounded by the closed container is used as the exciting coil 18, there is a problem that the entire exciting coil 18 becomes a large-scale device.

On the other hand, in the latter method, a round pipe,
There is a risk that the refrigerant will be clogged in the refrigerant passage inside the square pipe,
Further, since the exciting coil 18 is configured by a wire material such as a round pipe or a square pipe having a refrigerant passage, there is a problem that the wire material cross-sectional area becomes large and a necessary current value of the power supply becomes large. In order to obtain a magnetic field with the same number of ampere turns, it is easier to design the power supply by increasing the number of coil turns to reduce the required current and increase the voltage.

The present invention has been made in view of the above problems, and it is possible to simplify refrigerant management, eliminate the need for an insulating refrigerant between coils, and further reduce the size of the excitation. It is an object to provide a microwave plasma device having a coil.

[0009]

In order to achieve the above-mentioned object, a microwave plasma apparatus according to the present invention comprises a microwave waveguide, a plasma generating chamber, a reaction chamber, etc., and is provided at least around the plasma generating chamber. In a microwave plasma device provided with an exciting coil, a water channel is formed in the frame main body of the exciting coil, and a plurality of winding frame bodies are provided extending from the frame main body in a direction substantially orthogonal to the axial direction, A feature is that a coil is interposed between these winding frames.

[0010]

According to the above-mentioned device, a water channel is formed in the frame body of the exciting coil, and a plurality of reels are extended from the frame body in a direction substantially orthogonal to the axial direction. Since the coil is interposed between the coils, the heat generated from the coil is cooled by the refrigerant circulating in the water channel without directly contacting it. Therefore, it is not necessary to use an insulating liquid such as Freon as a refrigerant, and water or the like can be used as a refrigerant, so that refrigerant management is very simple. Further, the exciting coil is manufactured without performing the complicated work of arranging the coil in a container and hermetically sealing it, and since the entire coil is not surrounded by the hermetically sealed container, it can be miniaturized.

[0011]

Embodiments of the microwave plasma apparatus according to the present invention will be described below with reference to the drawings. It should be noted that components having the same functions as those of the conventional example are designated by the same reference numerals. FIG. 1 is a cross-sectional view schematically showing an embodiment of the microwave plasma device according to the present invention, and the structure of the exciting coil 30 is different from that of the conventional device shown in FIG. An enlarged view of the exciting coil 30 is shown in FIG. As shown in FIGS. 1 and 2, the plasma generation chamber 11 and the microwave waveguide 15
An exciting coil 30 is concentrically arranged around one end of the exciting coil 30.
Is composed of a first coil 31 having a substantially cylindrical shape and a second coil 32 having a diameter larger than that of the first coil 31 and having a coaxial substantially cylindrical shape. The first coil 31 and the second coil 32 are respectively provided with a frame main body 33 having a substantially cylindrical shape coaxial with the plasma generation chamber 11, and extending from the frame main body 33 at a predetermined interval in a direction substantially orthogonal to the axial direction. A water channel 36 is formed in the frame main body 33, which is composed of a plurality of wound frame members 34 and a coil 35 interposed between the wound frame members 34. Further, a heat transfer body 37 such as silicon rubber having enhanced heat conductivity is interposed between the winding frame 34 and the coil 35.

In the exciting coil 30 constructed as described above, the frame main body portion 3 is formed by the circulation of the refrigerant into the water passage 36.
3 and the winding frame 34 are cooled, the heat generated by the coil 35 is efficiently absorbed via the heat transfer body 37 in contact with the coil 35, and the coil 35 is efficiently cooled. That is, in the exciting coil 30 according to the present embodiment, it is possible to efficiently cool the coil 35 with the refrigerant and the heat transfer body 37 without directly contacting the coil 35 with the refrigerant. Therefore, since it is not necessary to use an insulating liquid such as Freon as a refrigerant and water or the like can be used as a refrigerant, there is no need to perform complicated refrigerant management associated with the use of an insulating refrigerant, and refrigerant management is simple. Can be something. Further, the coil 35 can be manufactured without performing the complicated work of disposing the coil 35 in the container and sealing the coil 35, and the risk of refrigerant leakage can be avoided. Furthermore, since the entire coil 35 is not surrounded by a closed container as in the conventional case, a miniaturized exciting coil 30 can be obtained.

The exciting coil 30 having such a simple water-cooling function has an inner diameter of 500 mm and an outer diameter of 700 m.
m, total length 140 mm
We were able to realize a large magnetic field of 0 ampere-turn.

As shown in FIG. 1, the reaction chamber 1 is provided with an exciting coil 30 having the same structure as the above on the outer periphery of the reaction chamber 17.
7 may be arranged substantially concentrically. In this case, the magnetic field may be formed so that the plasma drawn toward the reaction chamber 17 side by the divergent magnetic field enters the sample S more perpendicularly. it can. In the above embodiment, the exciting coil 30 is composed of two coils, the first coil 31 and the second coil 32, but in another embodiment, it is composed of only the first coil 31. You can also Furthermore, in the above embodiment, the case where the heat transfer body 37 is interposed between the winding frame 34 and the coil 35 has been described, but the heat transfer body 3
7 may not be provided, and the cooling efficiency can be further improved by providing the heat transfer body 37 according to the heat removal capacity.

FIG. 3 shows another example in which the exciting coil is composed of a plurality of coils. As shown in FIG. 3, this exciting coil 40 is different from the exciting coil 30 shown in FIG.
Both the first coil 41 and the second coil 42 are the frame body 4
3 has a shape that expands downward. The other portions are configured similarly to those shown in FIG. 3, and in this case as well, the coil 35 can be cooled and the shape of the divergent magnetic field can be adjusted in the same manner as above.

As described above, in the microwave plasma apparatus according to the above embodiment, the frame main body 33 having the water channel 36 formed therein and the frame main body 33 in the direction substantially orthogonal to the axial direction. A winding frame body 3 extending at a predetermined interval and having a heat transfer body 37 arranged in a portion facing the coil 35.
Since the coil 35 is disposed so as to be sandwiched between the coil 4 and 4, the coil 35 can be efficiently cooled by the refrigerant and the heat transfer body 37 without directly contacting the refrigerant. Therefore, the small exciting coils 30 and 40 having a simple and reliable cooling function can be manufactured, and the performance of the microwave plasma device can be improved by using such exciting coils 30 and 40. ..

[0017]

As is apparent from the above description, in the microwave plasma device according to the present invention, the water passage is formed in the frame main body of the exciting coil, and the water flow path is substantially orthogonal to the axial direction from the frame main body. A plurality of reels are extended in the direction,
Since the coil is interposed between these reels, the coil can be cooled without directly contacting the refrigerant. Therefore, a small-sized exciting coil having a simple and reliable cooling function can be manufactured, and the performance of the microwave plasma device provided with this exciting coil can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a microwave plasma device according to the present invention.

FIG. 2 is an enlarged view of an exciting coil portion shown in FIG.

FIG. 3 is an enlarged view showing another embodiment of the exciting coil.

FIG. 4 is a sectional view schematically showing an example of a conventional microwave plasma device.

[Explanation of symbols]

 11 Plasma Generation Chamber 15 Microwave Waveguide 17 Reaction Chamber 30, 40 Excitation Coil 33, 43 Frame Main Body 34 Winding Frame 35 Coil 36 Water Channel

Claims (1)

Claim: What is claimed is: 1. A microwave plasma apparatus comprising a microwave waveguide, a plasma generation chamber, a reaction chamber, and the like, wherein an excitation coil is disposed at least around the plasma generation chamber, A waterway is formed in the frame body of
A microwave plasma apparatus comprising: a plurality of winding frame bodies extending from the frame body in a direction substantially orthogonal to the axial direction, and a coil interposed between the winding frame bodies.