JP3786893B2 - Alignment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a matching device, and more particularly to a matching device for matching a high-frequency power source and a load.
[0002]
[Prior art]
FIG. 6 is a block diagram showing a configuration of a conventional matching unit 30. As shown in FIG. In FIG. 6, the matching unit 30 is called a three-stub tuner and includes a main coaxial pipe 31 and variable-length coaxial pipes 36 to 38. The main coaxial waveguide 31 includes an inner conductor 32 and an outer conductor 33, and an input terminal 34 and an output terminal 35 provided at one end and the other end of the inner conductor 32, respectively. The input terminal 34 receives high frequency power from the high frequency power supply 42, and the output terminal 35 is connected to the load 43.
[0003]
Each of the variable length coaxial tubes 36 to 38 has a line length of λ / 2 (where λ is the wavelength of the high frequency power), and stands perpendicular to the main coaxial tube 31 with a spacing of λ / 4 from each other. It is installed. Each of the variable length coaxial tubes 36 to 38 includes an inner conductor 39, an outer conductor 40, and a ring electrode 41. The inner conductor 36 and the outer conductor 40 are connected to the inner conductor 32 and the outer conductor 33 of the main coaxial waveguide 31, respectively. The ring-shaped electrode 41 is inserted between the outer peripheral surface of the inner conductor 39 and the inner peripheral surface of the outer conductor 40 and is slidable in the length direction of the variable-length coaxial tubes 36 to 38. The inner conductor 39 and the outer conductor 40 are short-circuited by the ring electrode 41.
[0004]
When the position of the ring electrode 41 is changed, the impedance of the matching unit 30 changes. By matching the impedance seen from the input terminal 34 of the matching unit 30 to the load 43 side with the characteristic impedance of a power transmission line (not shown) between the high frequency power supply 42 and the input terminal 34, the load is reflected without reflecting the high frequency power. 43 can be supplied.
[0005]
[Problems to be solved by the invention]
However, the conventional matching unit 30 has a problem that when the high-frequency power is a relatively low frequency of 100 MHz to 500 MHz, the main coaxial pipe 31 and the variable length coaxial pipes 36 to 38 become long, resulting in a large apparatus size. It was.
[0006]
Moreover, since it was necessary to move the three ring-shaped electrodes 41 individually, it was not easy to achieve matching, and the response speed to load fluctuations was slow.
[0007]
Further, sliding between the ring-shaped electrode 41 and the conductors 39 and 40 generates wear and dust, which requires a lot of maintenance work for the apparatus.
[0008]
Therefore, a main object of the present invention is to provide an aligning device that has a small device size, a high response speed, and does not require maintenance.
[0009]
[Means for Solving the Problems]
A matching device according to the present invention is a matching device for matching a high-frequency power supply and a load, and a shield case to which a reference potential is applied and a tip end surface thereof are opposed to the inner surface of the shield case and stand in the shield case. Provided, a part of the side surface is connected to the high-frequency power source, the other part of the side surface is connected to the load, and is provided movably between the tip surface of the columnar electrode and the inner surface of the shield case, A dielectric member for adjusting the capacitance value between the tip surface of the columnar electrode and the inner surface of the shield case is provided.
[0010]
Preferably, the dielectric member is provided to be movable along a plane parallel to the tip surface of the columnar electrode, and the capacitance value is adjusted by adjusting an overlapping area between the dielectric member and the tip surface of the columnar electrode. The
[0011]
Further preferably, one end portion thereof is coupled to the dielectric member, and the other end portion thereof is projected out of the shield case, and a rotation shaft for rotating the dielectric member is provided.
[0012]
Further preferably, a drive unit is provided that is coupled to the other end portion of the rotation shaft and rotates the rotation shaft by a desired angle.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration of a semiconductor manufacturing apparatus according to an embodiment of the present invention. In FIG. 1, the semiconductor manufacturing apparatus includes a high-frequency power source 1, a high-frequency sensor 2, a matching unit 3, a reaction chamber 4, a controller 5, and a driving device 6.
[0014]
The high frequency power source 1 generates high frequency power having a desired frequency and power. The high frequency power generated by the high frequency power source 1 is given to the reaction chamber 4 via the high frequency sensor 2 and the matching unit 3. A part of the high-frequency power is reflected by the reaction chamber 4, and traveling wave power Pf and reflected wave power Pr are generated in a transmission line (not shown).
[0015]
The high frequency sensor 2 detects the voltage V and current I of the transmission line between the high frequency power source 1 and the matching unit 3, and based on the detection result, the characteristic impedance Z ₀ (for example, the ratio Z of the voltage V and current I) A signal VZ corresponding to a deviation with respect to 50 ohms) and a signal Vφ at a level proportional to the phase difference φ between the voltage V and the current I are output.
[0016]
The matching unit 3 makes the reflected wave power Pr the minimum value by making the impedance of the reaction chamber 4 seen from the input terminal side equal to the characteristic impedance Z ₀ of the transmission line between the high frequency power source 1 and the matching unit 3. Is. The impedance of the matching unit 3 can be controlled. The matching unit 3 will be described in detail later.
[0017]
The driving device 6 includes a motor, a gear, and the like, and drives the matching unit 3 according to the controller 5. The controller 5 adjusts the impedance of the matching register 3 via the driving device 6 so that the levels of the signals VZ and Vφ from the high-frequency sensor 2 become minimum values.
[0018]
In the reaction chamber 4, as shown in FIG. 2, for example, two parallel plate electrodes 7 and 8 are provided. One of the two electrodes 7 and 8 receives high-frequency power from the high-frequency power source 1, and the other electrode 8 is grounded, for example. A substrate 9 is set on the surface of the electrode 8.
[0019]
At the time of etching or film formation, first, air in the reaction chamber 4 is discharged by a vacuum pump (not shown). Next, a predetermined gas is introduced into the reaction chamber 4 at a predetermined flow rate, and the exhaust speed of the vacuum pump is adjusted to adjust the inside of the reaction chamber 4 to a predetermined pressure.
[0020]
Next, the high-frequency power source 1 is turned on and a predetermined high-frequency power is applied to the reaction chamber 4, and the gas between the electrodes 7 and 8 is ionized to be in a plasma state. At this time, the impedance of the matching unit 3 is controlled by the high-frequency sensor 2, the controller 5, and the driving device 6 so that the reflected wave power Pr becomes a minimum value. When an etching gas (for example, CF ₄ ) is used, the surface of the substrate 9 is etched, and when a film forming gas (for example, SiH ₄ ) is used, a film is deposited on the surface of the substrate 9.
[0021]
3 (a) and 3 (b) are cross-sectional views showing the configuration of the matching device 3. In particular, FIG. 3 (a) shows a cross-sectional view taken along line YY 'of FIG. ) Shows a cross-sectional view taken along line XX ′ of FIG. 3A and 3B, the matching unit 3 includes a cylindrical shield case 11 whose upper and lower ends are closed, and a columnar column vertically installed at the center of the floor surface 12 of the shield case 11. And a load electrode 15. The tip surface of the load electrode 15 and the ceiling surface of the shield case 11 are grounded in parallel through a predetermined distance.
[0022]
The shield case 11 is formed of, for example, an aluminum alloy and receives the ground potential GND. The load electrode 15 is made of, for example, copper, and its lower end surface is electrically connected to the floor surface 12 of the shield case 11.
[0023]
The matching unit 3 includes a rod-shaped input electrode 16 and an output electrode 17. The input electrode 16 passes through the cylindrical portion 13 of the shield case 11 and is provided vertically at a predetermined position on one side of the outer peripheral surface of the load electrode 15. The output electrode 17 passes through the cylindrical portion 13 of the shield case 11 and is provided vertically at a predetermined position on the other side of the outer peripheral surface of the load electrode 15. The input electrode 16 and the output electrode 17 are made of, for example, copper, are electrically connected to the load electrode 15, and are insulated from the shield case 11. The portions of the input electrode 16 and the output electrode 17 that protrude outside the shield case 11 become the input terminal 16a and the output terminal 17a of the matching unit 3, respectively. The input terminal 16 a receives high frequency power from the high frequency power source 1, and the output terminal 17 a is connected to one electrode 7 of the reaction chamber 4.
[0024]
Further, the matching unit 3 includes a dielectric plate 18 and a rotating shaft 19. The rotating shaft 19 passes through the end portion of the upper lid portion 14 of the shield case 11 and is provided perpendicular to one end portion of the dielectric plate 18. The rotating shaft 19 is rotatably supported by the upper lid portion 14 of the shield case 11. A portion of the rotating shaft 19 that protrudes outside the shield case 11 is coupled to the driving device 6.
[0025]
The other end of the dielectric plate 18 extends to above the front end surface of the load electrode 15 and is formed to have the same size as or larger than the front end surface of the load electrode 15. The dielectric plate 18 is made of a high dielectric constant material such as quartz or Teflon (R). The rotating shaft 19 is made of plastic, for example.
[0026]
When the rotary shaft 19 is rotated, the dielectric plate 18 rotates and moves along a plane parallel to the tip surface of the load electrode 15 between the tip surface of the load electrode 15 and the ceiling surface of the shield case 14. When the dielectric plate 18 is rotated and moved, as shown in FIG. 4, the overlapping area S (shaded portion) between the tip surface of the load electrode 15 and the dielectric plate 18 changes, and the tip surface of the load electrode 15 and the shield case are changed. The capacitance value between the 11 and the ceiling surface changes. The change in the capacitance value increases as the dielectric constant of the dielectric plate 18 increases.
[0027]
The matching unit 3 constitutes a distributed constant circuit for high frequency power of 100 MHz to 900 MHz. A distributed capacitance is generated between the outer peripheral surface of the load electrode 15 and the inner peripheral surface of the shield case 11, and a distributed capacitance is generated between the front end surface of the load electrode 15 and the ceiling surface of the shield case 11. Distributed inductance is generated in the length direction of the electrode 15. When the rotary shaft 19 is rotated, the overlapping area S changes, the distributed capacitance between the tip surface of the load electrode 15 and the ceiling surface of the shield case 11 changes, and the impedance of the matching unit 3 changes.
[0028]
FIG. 5 is a Smith chart showing the relationship between the overlapping area S and the output impedance in the matching unit 3. The output impedance of the matching unit 3 was measured by an impedance analyzer in which the input terminal 16a was grounded through a 50Ω resistance element and connected to the output terminal 17a. In FIG. 5, the overlapping area S is expressed as a ratio (%) to the maximum value. The overlapping area S is 0, 50, and 100% at points A, B, and C, respectively. From FIG. 5, the reactance of the output impedance of the matching device 3 can be continuously changed from the minus side to the plus side, and matching can be achieved even if the reactance of the load changes from the plus side to the minus side. I know that there is.
[0029]
In this embodiment, since the coaxial tubes 31, 36 to 38 are not used unlike the conventional matching unit 30 shown in FIG. 6, even when the frequency of the high frequency power is low, the size of the apparatus does not increase.
[0030]
In addition, since the alignment can be achieved only by rotating the dielectric plate 18, the alignment can be easily performed as compared with the conventional case in which the positions of the three ring electrodes 41 need to be adjusted, and the response to the load fluctuation. Increases speed.
[0031]
Further, there is no sliding portion between the metals such as the sliding portions of the ring electrode 41 and the conductors 39 and 40, and no wear or dust is generated on the sliding portion, so that maintenance is not required.
[0032]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0033]
【The invention's effect】
As described above, in the matching device according to the present invention, the shield case to which the reference potential is applied, and the front end surface of the shield case are opposed to the inner surface of the shield case and are erected in the shield case. A columnar electrode connected to the other side of the side surface of the columnar electrode, and movable between the front end surface of the columnar electrode and the inner surface of the shield case; and the front end surface of the columnar electrode and the inner surface of the shield case; And a dielectric member for adjusting a capacitance value between them. Therefore, since the coaxial tube is not used as in the prior art, the size of the apparatus does not increase even when the frequency of the high frequency power is low. In addition, it is possible to achieve matching only by moving the dielectric member and adjusting the capacitance value between the tip end surface of the columnar electrode and the inner surface of the shield case, and the response speed with respect to load fluctuation is increased. Further, there is no sliding portion between metals as in the prior art, and no wear or dust is generated on the sliding portion, so that maintenance is not required.
[0034]
Preferably, the dielectric member is provided to be movable along a plane parallel to the tip surface of the columnar electrode, and the capacitance value is adjusted by adjusting an overlapping area between the dielectric member and the tip surface of the columnar electrode. The In this case, the capacitance value can be easily changed.
[0035]
Further preferably, one end portion thereof is coupled to the dielectric member, and the other end portion thereof is projected out of the shield case, and a rotation shaft for rotating the dielectric member is provided. In this case, the dielectric member can be moved with the simplest configuration.
[0036]
Further preferably, a drive unit is provided that is coupled to the other end portion of the rotation shaft and rotates the rotation shaft by a desired angle. In this case, the rotation axis can be easily and accurately rotated by a desired angle.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a semiconductor manufacturing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a reaction chamber shown in FIG.
3 is a cross-sectional view showing a configuration of the matching device shown in FIG. 1. FIG.
4 is a diagram for explaining the operation of the matching device shown in FIG. 3; FIG.
FIG. 5 is another diagram for explaining the operation of the matching unit shown in FIG. 3;
FIG. 6 is a block diagram showing a configuration of a conventional matching device.
[Explanation of symbols]
1,42 High-frequency power source, 2 High-frequency sensor, 3,30 Matching device, 4 Reaction chamber, 5 Controller, 6 Driving device, 7, 8 Parallel plate electrode, 9 Substrate, 11 Shield case, 12 Floor surface, 13 Cylindrical part, 14 Top cover, 15 Load electrode, 16 Input electrode, 16a, 34 Input terminal, 17 Output electrode, 17a, 35 Output terminal, 18 Dielectric plate, 19 Rotating shaft, 31 Main coaxial tube, 32, 39 Internal conductor, 33, 40 External conductor, 36-38 variable length coaxial tube, 41 ring electrode, 43 load.

Claims (4)

A matching device for matching a high frequency power source and a load,
A shield case to which a reference potential is applied,
A columnar electrode whose front end face is opposed to the inner surface of the shield case and is erected in the shield case, a part of the side surface is connected to the high-frequency power source, and the other part of the side surface is connected to the load; And a dielectric member provided so as to be movable between the tip surface of the columnar electrode and the inner surface of the shield case, and for adjusting a capacitance value between the tip surface of the columnar electrode and the inner surface of the shield case. A matching device. The dielectric member is provided to be movable along a plane parallel to the tip surface of the columnar electrode,
The matching device according to claim 1, wherein the capacitance value is adjusted by adjusting an overlapping area between the dielectric member and a tip surface of the columnar electrode. 3. The alignment according to claim 2, further comprising: a rotating shaft for rotating one of the ends of the dielectric member, one end of which is coupled to the dielectric member, and the other end of the other end is projected out of the shield case. apparatus. The alignment apparatus according to claim 3, further comprising a drive unit coupled to the other end of the rotating shaft and configured to rotate the rotating shaft by a desired angle.

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