JP2002016125A - Board rotation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a board rotation device which loads a board and a board holder, composes/integrates supported/rotated magnetic bearing and motor, can make them into a unit and to be compact and can permit the load fluctuation on a rotation part. SOLUTION: The board rotation device is provided with a rotor constituted of a circular and solid magnetic material and a motor where yokes (15-1 to 3) constituted of solid magnetic materials are arranged, DC magnetic flux sources (permanent magnets 15-4 and 5) are arranged in a magnetic circuit formed of the rotor 13 and the yokes, a plurality of axial shaft control coil wires and radial shaft control coil wires are installed in the yokes, a controller applying AC voltage to the axial shaft control coil wires and the radial shaft control coil wires is connected, at least a capacitor is connected in series to the electric circuit and the self-control magnetic bearing is constituted, coil wires for rotation are arranged in the yokes and rotary driving force is given to the rotor by magnetic flux with the DC magnetic flux sources and the coil wires for rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate used in a substrate processing apparatus for performing various processes (such as film forming process, annealing process, oxidative diffusion process, sputtering process, and etching process) on a substrate such as a semiconductor wafer having a large diameter. The present invention relates to a rotating device.

[0002]

2. Description of the Related Art A conventional technique of this kind is disclosed in US Pat. No. 6,022,413. This is an apparatus for rotating a substrate at high speed to improve the performance of substrate processing. In this device, a rotating body is a hollow rotor, which is supported by a magnetic force by a magnetic bearing, and is driven to rotate by a magnetic force by a motor. However, this device structurally occupies a long space in the vertical axis direction, which may hinder the device design. There is also a demand for increasing the bore diameter of the hollow rotor in order to increase the degree of freedom in design, such as the arrangement of device components penetrating the center of the hollow rotor.

[0003] In the annealing apparatus, 5 to 7 to improve the temperature distribution on the substrate to be processed has conventionally been used.
For example, a structure that rotates about 0 [rpm]
It is known from U.S. Pat. No. 5,965,047. The substrate and the substrate holder are mounted on a cylindrical hollow rotor, which is supported by a ball bearing and transmitted by a main rotating shaft connected to a rotating gear. Since the rotational speed was relatively low, the diameter of the hollow rotor was large, but the peripheral speed of the support member was low, and it was considered that a contact-type bearing could be used.

However, with the increase in the degree of integration of semiconductor devices, the line width of wiring has become increasingly narrower, and contact type bearings cannot meet the required performance due to problems such as generation of particles. Therefore, a structure that employs a magnetic bearing and supports the hollow rotor in a non-contact manner is essential. The use of a magnetic bearing enables higher-speed rotation, and further achieves a longer life.

[0005] In addition, a structure that occupies a long space in the vertical axis direction is not preferable due to a demand for apparatus design and maintenance of the apparatus. Therefore, the unit including the magnetic bearing and the motor needs to be flattened. For example, Tokiohei 11-51
Japanese Patent Publication No. 3880 discloses a technology relating to a magnetic levitation and rotation device that is a flat unit in which a magnetic bearing and a motor are combined and integrated. According to this document, feedback control is basically unnecessary for magnetic support, and non-contact magnetic support can be performed by passive control.

In this magnetic levitation and rotation device, a capacitor is connected in series between the exciting coil and the controller. As a main magnetoresistive element on the magnetic circuit having the exciting coil, there is a gap between the stator magnetic pole and the rotor magnetic pole, and the change in the gap changes the inductance of the coil. Therefore, if a constant-amplitude AC voltage with a frequency slightly higher than the series resonance frequency of the coil and the capacitor is applied to the electric circuit, the coil where the gap becomes large has a small inductance, so the coil current increases and the attractive force increases. Increase. Conversely, the current in the coil where the gap is small decreases, and the attractive force also decreases. As a result, the balance position can be controlled (= passive control).

However, when rotating at a high speed of about 1200 [rpm], feedback control (= active control) is performed by switching on the controller side. However, it is stated that an expensive displacement sensor is required for active control.

The above magnetic support technology has been actively studied in the 1960's, and was applied to bearings of inertial sensors (integrating gyros, accelerometers for guidance) in Japan in the 1970's to improve the accuracy of navigation systems such as rockets. There is a research report to do. That is, it is a known magnetic levitation principle. However,
At least research results in Japan have shown that static stability can be achieved, but dynamic stability requires the addition of a secondary damping element. It is understood that contact cannot be achieved and is a technology that has disappeared from the classification of magnetic bearings.
Hereinafter, this technique is referred to as a series resonance type magnetic bearing. Incidentally, the method of magnetically supporting by induced repulsion is a parallel resonance type.

It is obvious that the rotating device disclosed in the above-mentioned Japanese Patent Publication No. 11-513880 has excellent characteristics as a substrate rotating device. However, for example, a rotating device used in a semiconductor manufacturing apparatus is always improved. Improved,
There is a destined to evolve, static mass load such as the substrate to be loaded, the substrate holder (substrate susceptor) that holds the substrate,
The load on the magnetic bearing, such as the dynamic load due to process gas liquid, changes. In particular, it is desired that the fluctuation of the load acting on the vertical axis can be easily tolerated.

[0010] However, the above-mentioned Japanese Patent Application Laid-Open No. 11-5138.
In the structure of the rotating device disclosed in Japanese Patent Publication No. 80, the allowable load value in the vertical direction is determined by the initial design, and the allowable value of the finished product cannot be expanded by any adjustment. In other words, the load specifications must be strictly determined before production.

In a next-generation semiconductor device that requires a high degree of integration, the line width of the wiring is set to 0.1 according to the design rule.
μm or less is required. In the development of a manufacturing device for such a highly integrated semiconductor device, further improvement in device performance is required, and a degree of freedom in device design is required. Therefore, in the substrate rotating apparatus, it is required to mount the substrate and the substrate holder (substrate susceptor), combine and integrate the supporting and rotating magnetic bearing and the motor into a unit, and to further reduce the size. It is also required that the load fluctuation of the rotating part can be tolerated. In particular, when designing a new substrate rotating device, the peripheral components of the substrate such as the substrate holder are important factors for the process performance. Requested.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a structure in which a substrate and a substrate holder are stacked.
It is an object of the present invention to provide a substrate rotating device that can be combined and integrated into a unit by integrating and integrating a magnetic bearing and a motor that supports and rotates, and that can be made compact and that can tolerate fluctuations in the load of a rotating part.

[0013]

According to the first aspect of the present invention, there is provided a rotor made of an annular solid magnetic material and a yoke made of a solid magnetic material disposed on the outer periphery of the rotor. Is arranged, a DC magnetic flux source is provided in a magnetic circuit formed by the rotor and the yoke, a plurality of axial axis control windings and radial axis control windings are mounted on the yoke, and the axial axis control windings and A controller for applying an AC voltage to each of the radial shaft control windings is connected, and at least a capacitor is connected in series to the electric circuit to form a self-control magnetic bearing. The substrate rotating apparatus further comprises: a motor that applies a rotational driving force to the rotor by the magnetic flux generated by the DC magnetic flux source and the rotational driving winding.

As described above, by connecting a capacitor in series to an electric circuit for applying an AC voltage to the axial control winding and the radial shaft control winding to form a self-control type magnetic bearing, an expensive displacement sensor can be provided. An unnecessary and simple controller can be used as the passive controller.

[0015] Further, since the axial circuit winding has a magnetic circuit structure capable of adjusting the load capacity in the vertical axis direction,
For example, a substrate rotating device that can follow the evolution of semiconductor manufacturing equipment can be used.

Further, since the rotor and the yoke are made of a solid magnetic material, the rotor motion is damped by hysteresis loss and eddy current loss on the magnetic circuit. Therefore, it is necessary to provide a separate damping mechanism such as an oil damper. There is no clean structure.

Since the magnetic circuit for magnetic support and the magnetic circuit for rotational drive are combined, the device can be made compact.

According to a second aspect of the present invention, there is provided the substrate rotating apparatus according to the first aspect, wherein the upper, lower, lower, and upper portions in the yoke vertical direction are provided.
It is a stage configuration, and a permanent magnet which is a DC magnetic flux source is arranged between the upper yoke and the middle yoke and between the middle yoke and the lower yoke. A radial axis control winding is mounted on the yoke.

According to a third aspect of the present invention, in the substrate rotating apparatus according to the second aspect, a magnetic pole piece is disposed between a front end surface of the upper yoke and an upper end surface of the rotor.

According to a fourth aspect of the present invention, in the substrate rotating apparatus according to the third aspect, the tip of the upper yoke extends to the upper end face of the rotor.

[0021] The invention described in claim 5 is the first or second invention.
Wherein a partition made of a non-magnetic material is provided between the rotor and the stator including the yoke and each winding, and the stator is isolated from the space where the rotor is located.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a cross-sectional configuration of a substrate processing apparatus using a substrate rotating apparatus according to the present invention,
FIG. 2 is a diagram showing the rotating device, and FIG.
FIG. 4 is a sectional view taken along the line II-II of FIG. 1, and FIG. 5 is a sectional view taken along the line III-III of FIG.

In FIG. 1, reference numeral 1 denotes a substrate processing chamber for processing a substrate, and reference numeral 10 denotes a substrate rotating device. The substrate rotating device 10 is arranged so that its upper part is located at the center of the substrate processing chamber 1. The substrate processing apparatus places the vertical axis on the three-dimensional orthogonal coordinate system with the Z axis, loads the substrate 12 on the substrate holder 11 of the substrate rotating device 10 located at the center of the substrate processing chamber 1, and performs the desired processing. Can be implemented. Reference numeral 3 denotes a gate valve provided at the loading / unloading port of the substrate processing chamber 1.

A lamp heater 2 is disposed on the upper inner wall of the substrate processing chamber 1 so as to face the substrate 12 to be processed, and supplies energy for processing to the substrate 12 as heat energy. Reference numeral 13 denotes a ring-shaped rotor, and the substrate holder 1 is attached to the rotor 13 via a support member 14.
1 is supported. Reference numeral 15 denotes a stator, which is arranged on the outer periphery of the rotor 13 so as to surround the rotor 13. The rotor 13 is coupled to and supported by the stator 15 by magnetic force. The stator 15 is separated from the space in the substrate processing chamber 1 by a partition wall 16. Reference numerals 4 and 5 denote refrigerant lines provided on the side walls of the substrate processing chamber 1 for passing a coolant such as cooling water, 6 denotes a reflecting plate for reflecting heat energy from the lamp heater 2, and 7 denotes a substrate that pushes up the substrate 12 to be processed. It is a push-up pin.

The stator 15 includes a yoke 15-1 with an axial control winding, a yoke 15-2 with a rotation driving winding, a yoke 15-3 with a radial control winding, a permanent magnet (DC magnetic flux source 1) 15-4, and a permanent magnet. The magnet (DC magnetic flux source 2) 15-5 is configured. A magnetic pole piece 15-6 is provided on the substrate processing chamber 1 side of the partition wall 16, and a magnetic attractive force acts between the lower surface of the magnetic pole piece 15-6 and the upper surface of the rotor 13 to generate a main supporting force in the vertical direction. The details are shown in FIGS.

A silicon substrate, a quartz substrate, and a germanium substrate are used as the substrate 12 to be processed. Substrate holder 11
Are quartz, silicon carbide (SiC), steatite (MgO
· SiO ₂ ) and mullite (3Al ₂ O ₃ · 2SiO ₂ ). The support member 14 is made of quartz, silicon carbide (SiC), steatite (MgO.SiO ₂ ),
It is made of a material such as mullite (3Al ₂ O ₃ .2SiO ₂ ) and stainless steel.

The rotor 13 is made of permalloy (PB, P
C), electromagnetic stainless steel, Fe-Si steel, electromagnetic soft iron (S
(UY-B, SUY-P) and the like.
In order to improve the corrosion resistance, coating such as nickel plating is performed. The partition 16 is made of a nonmagnetic material such as austenitic stainless steel (SUS316, SUS304), polyether / etherketone (PEEK), and aluminum alloy.

The yokes 15-1, 15-2, 15-3, and 15-3 are made of solid permalloy (P
B, PC), magnetic stainless steel, and Fe-Si steel. In the permanent magnet 15-4 and the permanent magnet 15-5,
A samarium / cobalt magnet or an iron / neodymium / boron magnet is used. In order to improve the corrosion resistance, coating such as nickel plating is performed.

The yoke with axial control winding 15-1, the yoke with rotary driving winding 15-2, and the yoke with radial control winding 15-3 have the same yoke shape, coil shape and number. I have. Because this is possible,
Parts can be shared, and cost merit can be expected by reducing the number of parts.

The monitoring displacement sensors 17, 18, and 19 respectively detect the X-axis, Y-axis, and Z-axis displacements, and send signals to a controller (not shown).
It is used for the detection of the abnormality of the position.

The yoke 15-1 with the axial control winding, the yoke 15-2 with the rotation driving winding, the yoke 15-3 with the radial control winding, the rotor 13, and the magnetic pole piece 15- of the substrate rotating device 10 of the above substrate processing apparatus. The magnetic flux distribution by the magnetic circuit portion formed by the permanent magnets 6 and the permanent magnets 15-4 and 15-5 is shown in FIG.
It is shown as follows. Φ1 is a magnetic flux from the permanent magnet (DC magnetic flux source 1) 15-4, and Φ2 is a magnetic flux from the permanent magnet (DC magnetic flux source 2) 15-5. As shown in the figure, a magnetic circuit for generating magnetic support for generating a main support force acting between the lower surface of the magnetic pole piece 15-6 and the upper surface of the rotor 13 and a magnetic circuit for rotational driving for rotating the rotor 13 are shared and combined. I have.

As shown in FIG. 3, a part of the stator magnetic path is scattered inside the partition 16. With this structure, the assemblability of the stator 15 is improved. The magnetic flux Φ1 from the permanent magnet (DC magnetic flux source 1) 15-4 is closed through the yoke 15-1 with the axial control winding and the yoke 15-2 with the rotation driving winding. Further, a permanent magnet (DC magnetic flux source 2) 15
The magnetic flux Φ2 due to −5 is applied to a yoke 15-2 with a rotary drive winding,
It is closed through the yoke 15-3 with the radial control winding.

As shown in FIG. 3, the sectional structure of the yoke 15-1 with the axial control winding is such that the winding coil 15 is mounted on a large number (48 in the figure) of magnetic poles 15-1b arranged at equal intervals on the circumference. -1a is attached. Winding coil 15-
An AC voltage is applied to 1a from a controller (not shown), and a capacitor is provided in series on the electric circuit.
Further, the winding shapes of the winding coils 15-1a are all the same, but the four groups Z1, Z2, Z
3 and Z4, and may be respectively connected to a drive controller (not shown). As the diameter of the substrate to be processed 12 increases,
This grouping is preferably subdivided. By grouping, the tilting movement around the radial X axis and Y axis can also be controlled.

The technology of this magnetic bearing is described in “Dynamic Characteristics Analysis of Magnetic Supporting Device Using LRC Resonant Circuit”, Journal of the Institute of Electrical Engineers of Japan,
VOL. 94-B, no. 9. Article number: 49-B5
5, 1974, “Theoretical Analysis of Self-Controlled Octopole Magnetic Bearing System”, Precision Machinery, Vol. 40, No. 7, 1974, and the like. As stated above, at least research in Japan has shown that this magnetic bearing can achieve static stability, but dynamic stability requires the addition of a secondary damping element. It is understood that complete non-contact cannot be realized only with a portion hereinafter referred to as a bearing, and this technology has disappeared from the classification of magnetic bearings.

In view of the dynamic stability, a magnetic material constituting a magnetic circuit is intentionally made solid (not laminated) so that hysteresis loss and eddy current loss are liable to occur, and a DC excitation source such as a permanent magnet is used. By using the fact that when there is a movement in which the gap, which is the resistance on the magnetic circuit, changes, the damping effect is generated, and by having a damping element = damper,
It has a structure to obtain dynamic stability. Also, the stator 15
The secondary circuit generated in the partition 16 made of a non-magnetic material that separates the rotor 13 from the rotor 13 also contributes to obtaining dynamic stability.

The sectional structure of the yoke 15-2 with the rotary drive winding is as shown in FIG. 4. On this surface, the magnetic pole becomes an N pole by a permanent magnet 15-4 and a permanent magnet 15-5. ing. That is, since there is only a single pole on this circumference, the motor is classified as a homopolar motor. A large number (48 in the figure) of magnetic poles 15-2b arranged at equal intervals on the circumference have winding coils 1
5-2a is mounted. Although the winding shapes of the winding coils 15-2a are all the same, there are roughly three groups (A
A ′, BB ′, and CC ′), which are controlled by a drive controller (not shown).

The sectional structure of the yoke with the radial control winding is as follows.
It is as shown in FIG. The principle of the magnetic bearing is the same as that of the above-described yoke with axial control winding 15-1.
Therefore, an expensive displacement sensor for position control and feedback control using a complicated control circuit become unnecessary.

FIG. 6 is a diagram showing another example of a sectional configuration of the substrate rotating apparatus according to the present invention. The point that the present substrate rotating apparatus differs from the sectional structure of the substrate rotating apparatus shown in FIG.
-6, and is integrated with the yoke 15-1 with the axial control winding. Thus, the yoke 15-1 with the axial control winding is provided without providing a separate magnetic piece.
By integrating with the structure, assemblability is improved as compared with the structure shown in FIG.

FIG. 7 is a diagram showing another example of the sectional configuration of the substrate rotating apparatus according to the present invention. This substrate rotating apparatus differs from the cross-sectional structure of the substrate rotating apparatus shown in FIG. 6 in that monitoring displacement sensors 17, 18, and 19 are arranged outside the rotor 13. Thus, the monitoring displacement sensors 17, 18, 1
By arranging 9 outside the rotor 13, the inside of the rotor 13 can be used as a space occupied by components of the substrate processing apparatus (for example, components of the semiconductor manufacturing apparatus).

[0040]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

By connecting a capacitor in series to an electric circuit for applying an AC voltage to the axial shaft control winding and the radial shaft control winding to form a self-control type magnetic bearing,
An expensive displacement sensor is not required, and the controller can be a passive controller having a simple configuration, so that the substrate rotating device can be provided at low cost.

Also, since the magnetic circuit structure is such that the load capacity in the vertical axis direction can be adjusted by the axial control winding, it is possible to provide a substrate rotating apparatus that can follow, for example, the evolution of semiconductor manufacturing equipment.

Also, since the rotor and the yoke are made of a solid magnetic material, a damping action is given to the rotor motion by hysteresis loss and eddy current loss on the magnetic circuit.
There is no need to provide a separate damping mechanism such as an oil damper, and a substrate rotating device having a clean structure can be provided.

Since the magnetic circuit for magnetic support and the magnetic circuit for rotational drive are combined, a substrate rotating device having a compact structure can be provided.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a sectional configuration of a substrate processing apparatus using a substrate rotating apparatus according to the present invention.

FIG. 2 is a diagram showing an example of a cross-sectional configuration of a substrate rotating device according to the present invention.

FIG. 3 is a sectional view taken along the line II in FIG. 1;

FIG. 4 is a sectional view taken along the line II-II in FIG.

FIG. 5 is a sectional view taken along the line III-III in FIG. 1;

FIG. 6 is a diagram showing an example of a cross-sectional configuration of a substrate rotating device according to the present invention.

FIG. 7 is a diagram showing a cross-sectional configuration example of a substrate rotating device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate processing chamber 2 Lamp heater 3 Gate valve 4 Refrigerant line 5 Refrigerant line 6 Reflector 7 Substrate push-up pin 10 Substrate rotating device 11 Substrate holder 12 Substrate to be processed 13 Rotor 14 Support member 15 Stator 15-1 With axial control winding Yoke 15-2 Yoke with rotation drive winding 15-3 Yoke with radial control winding 15-4 Permanent magnet (DC magnetic flux source 1) 15-5 Permanent magnet (DC magnetic flux source 2) 15-6 Magnetic pole piece 16 Partition wall 17 Monitoring Displacement sensor for X-axis 18 Displacement sensor for monitoring (for Y-axis) 19 Displacement sensor for monitoring (for Z-axis)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/22 511 H01L 21/22 511Q 5F045 21/3065 21/324 Q 21/324 21/302 B F term (Reference) 3J102 AA01 BA03 BA19 CA19 DA03 DA06 DA16 DA28 GA19 GA20 4K029 AA04 AA06 BD01 CA05 GA01 JA02 4K030 CA04 CA12 DA09 GA06 KA34 KA46 5F004 BD04 BD05 CA05 5F031 CA02 HA59 LA04 MA28 MA29 MA30 MA32 5F045 EM10

Claims (5)

[Claims] 1. A rotor made of an annular solid magnetic material, and a yoke made of a solid magnetic material arranged on the outer periphery of the rotor, and a DC magnetic flux source is provided in a magnetic circuit formed by the rotor and the yoke. Provided, a plurality of axial axis control windings and radial axis control windings are mounted on the yoke,
A controller for applying an AC voltage is connected to each of the axial-axis control winding and the radial-axis control winding, and at least a capacitor is connected in series to the electric circuit to form a self-control type magnetic bearing. Wherein a rotating drive winding is provided, and a motor for applying a rotating drive force to the rotor by the rotating drive winding and the rotating drive winding is provided. 2. The substrate rotating device according to claim 1, wherein the DC magnetic flux has a three-stage configuration of upper, middle, and lower in the yoke vertical direction, and between the upper yoke and the middle yoke and between the middle yoke and the lower yoke. A substrate rotating apparatus comprising a permanent magnet as a source, an axial axis control winding mounted on an upper yoke, a rotation drive winding mounted on a middle yoke, and a radial axis control winding mounted on a lower yoke. 3. The substrate rotating device according to claim 2, wherein a magnetic pole piece is arranged between a tip end surface of the upper yoke and an upper end surface of the rotor. 4. The substrate rotating device according to claim 3, wherein a tip of the upper yoke extends to an upper end surface of the rotor. 5. The substrate rotating apparatus according to claim 1, wherein a partition made of a non-magnetic material is provided between the rotor and the stator including the yoke and the windings, and the rotor is positioned on the stator. A substrate rotation device characterized by being isolated from space.