阅读说明：本技术 用于石英晶体振荡式薄膜厚度监视器的传感器头 (Sensor head for quartz crystal oscillating film thickness monitor ) 是由 小熊洋介 前田章弘 海田友纪 小高学 岗村衡 于 2018-03-06 设计创作，主要内容包括：一种用于石英晶体振荡式薄膜厚度监视器的传感器头,其具有配置有驱动装置的传感器头主体,由驱动装置旋转驱动且在同一圆周上间隔设置有多个石英振子保持件,设置在传感器头主体上的掩膜体,并覆盖设置有各石英振子的保持件的上表面,且开设有朝向任意一个石英振子的成膜用窗口；传感器头具有固定在位于成膜用窗口正下方的传感器头主体部分上的第一电极；分别与各石英振子导通且向保持件下表面突出设置的第二电极；当保持件旋转到一个石英振子和成膜用窗口在上下方向上相匹配的相位时,第一电极和第二电极抵接并导通；还配置有绝缘体,其位于第一电极或第二电极任意一方的保持件的旋转方向两侧,且第一电极或第二电极中的任意另一方在其上滑动。(A sensor head for a quartz crystal oscillation type film thickness monitor has a sensor head main body provided with a driving device, a plurality of quartz vibrator holders rotationally driven by the driving device and arranged at intervals on the same circumference, a mask body arranged on the sensor head main body, covering the upper surface of the holder provided with each quartz vibrator, and provided with a film forming window facing any one quartz vibrator; the sensor head has a first electrode fixed to a main body portion of the sensor head located right below the film formation window; second electrodes respectively connected to the quartz resonators and protruding toward the lower surface of the holder; when the holder rotates to a phase where the quartz resonator and the film formation window are matched in the vertical direction, the first electrode and the second electrode are abutted and conducted; insulators are also provided, which are positioned on both sides of the holder in the direction of rotation of either the first electrode or the second electrode, and on which the other of the first electrode or the second electrode slides.)

1. A sensor head for a quartz crystal oscillating film thickness monitor, having: a sensor head main body provided with a driving device; a holder which is rotationally driven by a driving device and has a plurality of quartz oscillators provided at intervals on the same circumference; and a mask body provided on the sensor head main body so as to cover an upper surface of the holder on which each quartz resonator is provided, in a direction from the sensor head main body toward the holder, and having a film formation window facing any one of the quartz resonators;

the sensor head for a quartz crystal oscillation type film thickness monitor has: a first electrode fixed to a portion of the sensor head main body located immediately below the film formation window; and second electrodes that are respectively electrically connected to the quartz resonators and protrude toward the lower surface of the holder; when the holder is rotated to a phase where the quartz resonator and the film formation window are vertically matched, the first electrode and the second electrode are brought into contact with each other and conducted;

the sensor head for a quartz crystal oscillation type film thickness monitor is characterized in that:

insulators are also provided, which are positioned on both sides of the holder in the direction of rotation of either the first electrode or the second electrode, and on which the other of the first electrode or the second electrode slides.

2. A sensor head for a quartz crystal oscillatory film thickness monitor in accordance with claim 1 wherein:

the drive means has a stepper motor or a pneumatic rotary actuator.

3. A sensor head for a quartz crystal oscillatory film thickness monitor in accordance with claim 1 or 2, characterized in that:

the insulator is made of fluororesin.

Technical Field

The present invention relates to a sensor head for a quartz crystal oscillation type film thickness monitor, and more particularly, to a sensor head which is provided in a vacuum chamber of a film forming apparatus such as a vacuum deposition apparatus or a sputtering apparatus and which monitors a thickness of a film formed on a quartz resonator by measuring a resonance frequency of the quartz resonator during film formation in a vacuum atmosphere.

Background

Such a sensor head for a quartz crystal oscillation type film thickness monitor is known, for example, in patent document 1. The device has: a sensor head main body provided with a stepping motor (pulse motor for vacuum) as a driving device; and a holder which is rotationally driven by the stepping motor and in which a plurality of quartz resonators are arranged at intervals on the same circumference. A mask body is provided on the sensor head main body so as to cover the upper surface of the holder on which the quartz resonators are provided, with the direction from the sensor head main body toward the holder being set to be upward, and a film formation window facing one quartz resonator is opened at a predetermined position of the mask body.

The first electrode is provided at a portion of the sensor head main body located immediately below the film formation window. The first electrode is constituted by a plate-like member having one end fixed to a support base provided on the sensor head main body. The holding member is composed of a holding plate portion made of stainless steel and an annular plate portion made of fluororesin, wherein the holding plate portion is provided with a storage portion on the upper surface thereof in a recessed manner for storing each quartz resonator, the annular plate portion is integrally fixed to the lower surface of the holding plate portion, and the annular plate portion holds a wing-shaped electrode as a second electrode which is electrically connected to each quartz resonator. In this case, a part of the wing-like electrode protruding downward from the annular plate portion has a dome-shaped profile. When the holder is rotated by the stepping motor to a phase (normal (size)) matching one of the quartz resonator and the film formation window in the vertical direction, the second electrode is brought into contact with the free end portion of the first electrode and conducted, and the thickness of the thin film formed on the quartz resonator is monitored by measuring the resonance frequency of the quartz resonator in this state. When the measured resonance frequency changes beyond a predetermined range as the thickness of the formed thin film increases, for example, the service life is judged, and the holder is rotated again by the stepping motor to a phase at which the next quartz resonator and the film formation window are aligned in the vertical direction.

However, when the resonance frequency is measured, the driving current flowing through the quartz resonator is small, and is generally several mA. Therefore, for example, in consideration of use in a vacuum atmosphere, corrosion resistance, and resistance value, a gold material or a member having a gold plating layer formed on the surface of a metal material having good conductivity is generally used as the first electrode and the second electrode. However, when the contact portions of the first electrode and the second electrode are made of gold of the same metal, the stepping motor is liable to step out, and it is found that as the number of rotations of the holder increases, the excitation current flowing through the stepping motor increases to rotationally drive the holder. When the stepping motor is out of step, a phase shift of the quartz resonator with respect to the film formation window occurs (that is, the quartz resonator is shifted forward or backward in the rotational direction with respect to the film formation window due to the shift of the stop position of the holder forward or backward in the rotational direction) (in addition, if the deviation of the resonance frequency is not large, it cannot be determined whether the stepping motor is out of step), and further, when the exciting current is increased, the amount of heat generated by the stepping motor is increased, and the quartz resonator receives the heat, there is a problem that the thickness of the thin film formed on the quartz resonator cannot be accurately monitored.

Therefore, the inventors of the present application have made extensive studies and found that the cause of this is, in particular, roughness (surface unevenness) of the (gold) surface layer portion of the first electrode. That is, in any phase in which the quartz resonator and the film formation window are vertically matched, the contact state between the first electrode and the second electrode is maintained by the urging force of the first electrode, but since the hardness of gold is low, the contact portion between the first electrode and the second electrode is adhered. When the holder starts rotating from this state, the second electrode slides on the surface of the first electrode, so that the second electrode is forcibly peeled off, which repeatedly occurs, resulting in gradual roughening of the surface layer portion of the first electrode. As a result, the sliding resistance (frictional resistance) of the second electrode with respect to the first electrode during rotation of the holder is increased, and the stepping motor is likely to step out, and the exciting current of the stepping motor is increased.

Documents of the prior art

Patent document

[ patent document 1 ] patent No. 3953505

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a sensor head for a quartz crystal oscillation type thin film thickness monitor, which is provided to suppress a phase shift of a quartz resonator with respect to a film formation window due to step-out of a stepping motor and an increase in an excitation current of the stepping motor, and to accurately monitor the thickness of thin films formed on the quartz resonator at any time.

Means for solving the problems

To solve the above-mentioned technical problem, the sensor head for a quartz crystal oscillation type film thickness monitor of the present invention has: a sensor head main body provided with a stepping motor; a holder which is rotationally driven by a stepping motor and has a plurality of quartz oscillators provided at intervals on the same circumference; and a mask body provided on the sensor head main body so as to cover an upper surface of the holder on which each quartz resonator is provided, in a direction from the sensor head main body toward the holder, and having a film formation window facing any one of the quartz resonators; the sensor head for a quartz crystal oscillation type film thickness monitor further has: a first electrode fixed to a portion of the sensor head main body located immediately below the film formation window; and second electrodes that are respectively electrically connected to the quartz resonators and protrude toward the lower surface of the holder; in a structure in which a first electrode and a second electrode made of the same metal are brought into contact and conducted when a holder is rotated by a stepping motor to a phase in which one of a quartz resonator and a film formation window is vertically matched, the sensor head for a quartz crystal oscillation type thin film thickness monitor is characterized in that: the apparatus further includes a lubricant supply device for supplying a solid lubricant to a surface of at least one of the first electrode and the second electrode before any one of the first electrode and the second electrode is brought into contact with each other.

In the above aspect, since the solid lubricant is present in the contact portion between the first electrode and the second electrode in the phase in which the crystal resonator and the film formation window are vertically aligned, the adhesion at the contact portion can be suppressed. And the second electrode is smoothly slid on the surface of the first electrode by the solid lubricant while the holder is rotated. Therefore, even if the rotation operation of the holder is repeated, the roughness of the surface layer portion of the first electrode is suppressed as much as possible, and the sliding resistance of the second electrode with respect to the first electrode does not increase when the holder is rotated. As a result, the step-out of the stepping motor is suppressed, and the rise of the exciting current of the stepping motor is also suppressed. In addition to the above-described effects, the solid lubricant is not particularly required to have a material and a particle diameter as long as the function of bringing the first electrode and the second electrode into contact with each other and measuring the resonance frequency is not hindered. The present invention is not limited to the case of using a gold material or a member having a gold-plated layer formed on the surface of a conductive metal material as the first electrode and the second electrode, and can be applied to the case of using the first electrode and the second electrode made of the same metal such as copper or platinum.

In the present invention, it is preferable that the lubricant supplying device is provided adjacent to one of the first electrode and the second electrode, and is configured by a member having a sliding surface on which the other of the first electrode and the second electrode slides with rotation of the holder, the sliding surface having a lower vickers hardness than the other of the first electrode and the second electrode. Thus, for example, when the member is disposed adjacent to the first electrode, minute shavings generated when the second electrode slides on the sliding surface of the member are used as the solid lubricant, and the shavings are made to adhere to the second electrode and come into contact with the first electrode, whereby the lubricant supply device for supplying the solid lubricant to the surface of the second electrode before coming into contact with the first electrode can be realized with a simple configuration. In this case, if the sliding surface of the member is made of fluororesin or graphite, it is confirmed that the roughness of the surface layer portions of the first electrode and the second electrode can be suppressed as much as possible without impairing the function of measuring the resonance frequency when the first electrode and the second electrode are made of gold or a member having a gold-plated layer formed on the surface of a conductive metal material.

However, when the holder is rotated by the driving device and stopped at a predetermined rotation angle, a phase shift of the quartz resonator with respect to the film formation window occurs, and therefore, the thickness of the thin film formed on the quartz resonator cannot be accurately monitored. In this case, it is conceivable to provide a detection device for detecting that the quartz resonator is in a normal phase with respect to the film formation window, but this arrangement may not be provided in a limited space in the vacuum chamber, or may increase the number of components and increase the cost. Therefore, it is desirable to develop a sensor head for a quartz crystal oscillation type film thickness monitor having a simple structure, which is provided to monitor the thickness of a film formed on a quartz resonator only when the quartz resonator is in a normal phase with respect to a film formation window after rotating a holder without using a detection device.

Therefore, another aspect of the present invention relates to a sensor head for a quartz crystal oscillation type film thickness monitor, comprising: a sensor head main body provided with a driving device; a holder which is rotationally driven by a driving device and has a plurality of quartz oscillators provided at intervals on the same circumference; and a mask body provided on the sensor head main body so as to cover an upper surface of the holder on which each quartz resonator is provided, in a direction from the sensor head main body toward the holder, and having a film formation window facing any one of the quartz resonators; the sensor head for a quartz crystal oscillation type film thickness monitor has: a first electrode fixed to a portion of the sensor head main body located immediately below the film formation window; and second electrodes that are respectively electrically connected to the quartz resonators and protrude toward the lower surface of the holder; when the holder is rotated to a phase where the quartz resonator and the film formation window are vertically matched, the second electrode is brought into contact with and conducted with the first electrode; the sensor head for a quartz crystal oscillation type film thickness monitor is characterized in that: insulators are also provided, which are positioned on both sides of the holder in the direction of rotation of either the first electrode or the second electrode, and on which the other of the first electrode or the second electrode slides.

In the above aspect, when the holder is rotated by the drive device by a predetermined rotation angle, if the quartz resonator is in a normal phase with respect to the film formation window, the second electrode contacts the first electrode, and if the quartz resonator is shifted in phase forward and backward in the rotation direction of the holder with respect to the film formation window, the first electrode or the second electrode contacts only the insulator, and the first electrode and the second electrode are not electrically connected. The configuration in which the insulators are disposed on both sides of the holder of the first electrode or the second electrode in the rotation direction actually functions as a detection device for detecting that the holder is rotationally driven until the quartz resonator is in a normal phase with respect to the film formation window, and the thickness of the thin film formed on the quartz resonator can be monitored only when the quartz resonator is in the normal phase with respect to the film formation window after the holder is rotationally driven. Further, in the present invention, the case where the driving device has a stepping motor or a pneumatic rotary actuator (air pressure type ロータリーアクチュエータ) is particularly advantageous.

Drawings

Fig. 1 is an exploded perspective view of a sensor head for a quartz crystal oscillation type thin film thickness monitor shown in a state where a mask body is omitted according to an embodiment of the present invention.

Fig. 2 is a partial sectional view of a main portion of the sensor head.

Fig. 3 is a top view of a sensor head.

Fig. 4 is an exploded perspective view of a sensor head for a quartz crystal oscillation type thin film thickness monitor according to a modification of the present embodiment, shown with a mask body omitted.

Detailed Description

In the following, an embodiment of a sensor head for a quartz crystal oscillation type thin film thickness monitor according to the present invention will be described by taking a case where a driving device is a stepping motor as an example, and the thickness of a thin film formed on a quartz resonator can be monitored by measuring the resonance frequency of the quartz resonator when the thin film is formed in a vacuum chamber of a film forming device such as a vacuum deposition device or a sputtering device installed outside the figure and in a vacuum atmosphere. In the following, terms indicating the up and down directions are based on the posture of fig. 1. Since a known member can be used as the quartz resonator or a member or element for measuring the resonance frequency of the quartz resonator, detailed description thereof including a specific film thickness monitoring method is omitted.

Referring to fig. 1 to 3, SH is a sensor head for a quartz crystal oscillation type thin film thickness monitor of the present embodiment. The sensor head SH mainly has: a sensor head main body 1 in which a stepping motor Sm is arranged; a holder 2 which is rotationally driven by a stepping motor Sm and has a plurality of quartz resonators Co arranged at equal intervals on the same circumference; and a mask body 3 attached to the sensor head main body 1 so as to cover the upper surface of the holder 2 on which each quartz resonator Co is provided, and having a film formation window 31 opened therein so as to face any one of the quartz resonators Co. Since the mask body 3 is a publicly known member that can be used, further detailed description is omitted.

The first electrode 4 is provided on the upper plate portion 11 of the sensor head main body 1. The first electrode 4 has a long plate portion 4a having one end fixed to one direction on a support base 12 provided on the upper plate portion 11. In this state, the plate portion 4a is mounted in a posture extending in the tangential direction of the holder 2, and the free end portion thereof is positioned directly below the film formation window 31 (see fig. 2). A slide plate portion 4b as a slide surface 41 on which a portion 51 with a second electrode 5 described below slides is provided on the upper surface of the free end portion of the plate portion 4a. The slide plate portion 4b is made of a material having (electrical) insulation and having a lower vickers hardness than the portion 51 of the second electrode 5, and is made of, for example, a fluororesin material. The sliding surface 41 is formed of a flat portion 41a at the center and inclined surface portions 41b, 41b connected to both sides of the flat portion 41a in the tangential direction and inclined downward.

The flat portion 41a is provided with a slit hole 42 extending in a direction orthogonal to the tangential direction and penetrating in the plate thickness direction. A prism-shaped tangent point member 4c vertically provided on the plate portion 4a is fitted in the slit hole 42. In this case, the height of the contact point member 4c from the plate portion 4a is defined such that the upper surface of the contact point member 4c is positioned slightly below the upper surface of the flat portion 41a in the center. As the plate portion 4a and the contact point member 4c, a member in which a gold plating layer is formed on a relatively inexpensive metal surface having good conductivity, such as aluminum or copper, is used. The slit width Sw of the slit hole 42 (which substantially coincides with the width of the tangent line direction of the contact point member 4 c) is appropriately set within a predetermined range according to the contact area of the portion 51 of the second electrode 5 with respect to the contact point member 4c so that the portion 51 of the second electrode 5 can contact the upper surface of the contact point member 4c exposed from the slit hole 42 only when any one of the quartz resonator Co and the film formation window 31 is in the normal phase matching in the vertical direction.

Although not particularly illustrated, a through hole is formed in the center of the upper plate portion 11, and a base portion 13, in which the holder 2 is seated, is attached to a rotating shaft portion protruding above the upper plate portion 11, through which the rotating shaft of the stepping motor Sm attached to the sensor head main body 1 passes via a bearing. A boss portion 14 located on the axis of the rotation shaft is provided in a protruding manner on the base portion 13, a fixing bolt 15 penetrates the holder 2 through the boss portion 14, and the holder 2 is connected to the rotation shaft of the stepping motor Sm by the fixing bolt 15. Further, in the base portion 13, two protrusions 13a having a dome-shaped profile are provided on the same circumference with a shift of 180 degrees, and when each protrusion 13a is engaged with an engagement hole 22a provided on the lower surface of an annular plate portion 22 of the holder 2 described below, the holder 2 is positioned and phased with respect to the sensor head main body 1.

The holder 2 is composed of a stainless holding plate portion 21 and a fluororesin annular plate portion 22, wherein the holding plate portion 21 has a plurality of (12 in the present embodiment) storage portions 21a each storing a quartz resonator recessed in an upper surface thereof, the annular plate portion 22 is integrally fixed to a lower surface of the holding plate portion 21, a central hole of the annular plate portion 22 is fitted to the base portion 13, and the holder 2 is seated on the base portion 13. Further, a wing-shaped electrode (feather) is held on the ring board 22 as a second electrode 5 that is electrically connected to the quartz resonators Co stored in the storage section 21 a. Note that, a known structure may be used as the structure of the wing-like electrode itself or the structure held by the annular plate portion 22 in a state of conduction with the quartz resonator Co, and thus, a detailed description thereof will be omitted. As the wing-like electrode, a member formed by plating a gold layer on a relatively inexpensive metal surface having good conductivity, such as aluminum or copper, may be used, and the lower end of the wing-like electrode protrudes from below the annular plate portion 22, and the portion 51 of the second electrode 5 having a dome-shaped profile protruding therefrom is brought into contact with the upper surface of the contact point member 4c and electrically conducted.

When the thickness of the thin film formed on the quartz resonator Co is monitored by the sensor head SH, first, the stepping motor Sm is started in situ (origin point し) by a known method, and then a predetermined pulse signal is input, and accordingly, the holder 2 is rotated by the stepping motor Sm by a predetermined rotation angle. In this case, the holder 2 is stopped at a position of a normal phase where any one of the quartz resonator Co and the film formation window 31 are vertically matched. When the holder 2 rotates, the portion 51 of the second electrode 5 first comes into contact with the inclined surface 41b of the slide plate portion 41 located forward in the rotation direction of the holder 2, and as the holder 2 further rotates, it sequentially slides on the inclined surface 41b and the flat surface 41a of the slide plate portion 41 to move to a position where it comes into contact with the contact point member 4c of the first electrode 4. Further, since minute shavings generated when sliding on the inclined surface portion 41b and the flat portion 41a in this order are attached to the portion 51 of the second electrode 5, such minute shavings (not shown) exist at the contact portion between the contact point member 4c of the first electrode 4 and the portion 51 of the second electrode 5 in the normal phase.

Next, for example, when the measured resonance frequency changes beyond a predetermined range as the thickness of the formed thin film increases, the service life of any one of the quartz resonators Co is determined. Then, the predetermined pulse signal is input again, and the holder 2 is further rotated by the stepping motor Sm by a predetermined rotation angle in response thereto. In this case, the holder 2 is stopped at the normal phase in which the next quartz resonator Co and the film formation window 31 are vertically aligned, and at this time, minute shavings exist in the contact portion between the contact point member 4c of the first electrode 4 and the portion 51 of the second electrode 5, as described above. The operation is repeated thereafter.

In the above-described manner, the shavings generated by the sliding of the portion 51 of the electrode 5 on the sliding surface 41 of the sliding plate portion 4b are used as the solid lubricant, and the adhesion at the abutting portion can be suppressed by the presence of the solid lubricant at the abutting portion between the tangent point member 4c of the first electrode 4 and the portion 51 of the second electrode 5 in the normal phase where any one of the quartz resonator Co and the film formation window 31 match in the vertical direction. When the holder 2 rotates, the portion 51 of the second electrode 5 slides smoothly on the upper surface of the contact point member 4c of the first electrode 4 by the solid lubricant. Therefore, even if the operation of rotationally driving the holder 2 is repeated, the coarsening of the surface layer portion of the upper surface of the contact member 4c can be controlled as much as possible, and the sliding resistance does not increase. As a result, step-out of the stepping motor Sm is suppressed, and an increase in the excitation current of the stepping motor Sm is also suppressed. When the stop position of the holder 2 is shifted forward and backward in the rotation direction (i.e., shifted from the normal phase), the portion 51 of the second electrode 5 is in a state of being in contact with the sliding surface 41 of the sliding plate portion 4b as an insulator, without being in contact with the upper surface of the contact point member 4c of the first electrode 4. In this case, the resonance frequency cannot be measured, for example, the film thickness monitor itself fails to stop. As described above, in the present embodiment, the slide plate portion 4b constitutes a solid lubricant supply device, and actually functions as a detection device when the holder 2 is rotated, and detects that the holder is rotationally driven until the crystal resonator Co is in a normal phase with respect to the film formation window 31.

In order to confirm the above-described effects, the following experiments were carried out using the sensor head SH (invention product) of the above-described embodiment and a sensor head (corresponding to the above-described conventional example: conventional product) in which the first electrode is constituted only by the plate portion 4b. That is, the operation of sequentially rotating and stopping the quartz resonators Co in one direction by a predetermined rotation angle so as to be aligned in the vertical direction with respect to the film formation window 31 by the stepping motor Sm in a vacuum atmosphere is repeated, and the relationship between the number of rotations of the rotary holder (one rotation when the holder is rotated by 360 degrees) and the excitation current of the stepping motor Sm at this time is examined. Thus, it was confirmed that, in the conventional product, if a current of about 60% of the maximum field current of the stepping motor Sm does not flow when the holder is rotated 1000 revolutions, the holder 2 cannot be rotationally driven. In this case, it is confirmed that the resonance frequency is changed by the influence of heat from the stepping motor Sm. In contrast, it was confirmed that, in the invention product, even when the holder 2 rotates 1000 revolutions, the holder 2 can be rotationally driven with a current of about 15% of the maximum excitation current, and the change in the resonance frequency is not so large.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and can be modified as appropriate within a range not departing from the technical spirit of the present invention. In the above embodiment, the description has been given taking as an example a case where the contact point member 4c of the first electrode 4 and the portion 51 of the second electrode 5 which are in contact with each other are made of gold, but the present invention is also applicable to a case where the first electrode and the second electrode are made of the same metal such as copper or platinum.

In the above embodiment, the case where the solid lubricant supply device is configured by using the sliding plate portion 4b has been described as an example, but the present invention is not limited to this. For example, the solid lubricant supply device may be configured by providing a spraying device for spraying fine particles having a predetermined particle size onto the portion 51 of the second electrode 5 or a coating device for coating particles having a predetermined particle size onto the portion 51 of the second electrode 5 on the upper plate portion 11 of the monitor main body. In this case, the solid lubricant may be supplied not only to the portion 51 of the second electrode 5 but also to the upper surface of the contact point member 4c of the first electrode 4. Further, in the above-described embodiment, the case where the sliding plate portion 4b as the insulator is made of a fluororesin has been described as an example, but at least the sliding surface 41 may be made of a fluororesin, and when the sliding plate portion 4b functions only as a solid lubricant supply device, the sliding surface 41 need not be an insulator, and may be made of graphite, for example. In this case, as the stepping motor Sm, a resolver type (レゾルバ type) motor with a function of detecting a rotation angle may be used. On the other hand, the driving device may be constituted by a member having a pneumatic rotary actuator, for example, and in this case, if a configuration is adopted in which insulators are disposed on both sides of the holder 2 of the first electrode 4 in the rotation direction as described above, it is advantageous to eliminate the need to separately provide a detection device for detecting that the rotary drive holder 2 is in a normal phase with respect to the film formation window 31 until the quartz resonator Co is in a normal phase.

Further, the examples described in the above embodiments are: the slide plate portion 4b with the sliding surface 41 is provided on the upper surface of the free end portion of the plate portion 4a, the portion 51 of the second electrode 5 slides on the sliding surface 41, and the scraping chips are generated by the sliding of the portion 51 of the electrode 5 on the sliding surface 41 of the slide plate portion 4b, and the scraping chips are used as the solid lubricant, but the present invention is not limited thereto. In the modification of the present embodiment shown in fig. 4, a plurality of elongated slit-shaped recesses 222 may be formed in the radial direction on the lower surface 221 of the annular plate portion 22 made of a fluororesin, and in the recesses 222, the lower ends of the wing-shaped electrodes may be projected downward, and the portion 51 of the second electrode 5 having a dome-shaped profile of the projection may be brought into contact with the upper surface of the contact point member 4c. In this case, only the prism-shaped tangent point member 4c is vertically provided on the plate portion 4a. When the holder 2 is rotationally driven, the chips generated by the contact member 4c sliding on the lower surface 221 of the annular plate portion 22 are used as the solid lubricant, and the solid lubricant is located at the contact portion between the contact member 4c of the first electrode 4 and the portion 51 of the second electrode 5 at the normal phase where the quartz resonator Co and the film formation window 31 are vertically aligned. Further, since the portion 51 of the second electrode 5 is located in the slit-shaped recess 222, the detection holder functions as a detection device, and is rotationally driven until the quartz resonator Co is in a normal phase with respect to the film formation window 31, as in the above-described embodiment. In the above modification, the slit-shaped recess 222 is formed and the lower end of the wing-shaped electrode is projected downward in the recess 222, but the present invention is not limited to this, and a projection may be formed at a predetermined position on the lower surface 221 of the annular plate portion 22 made of fluororesin and the lower end of the wing-shaped electrode is projected downward in the projection.

Description of the reference numerals

SH. is used for a sensor head of a quartz crystal oscillation type film thickness monitor, 1. a sensor head main body, 2. a holder, 3. a mask body, 31. a film formation window, 4. a first electrode, 4a plate part, 4b. a sliding plate part with electrical insulation (solid lubricant supply device), 4c. a contact point part (essential part of the first electrode), 41. a sliding surface, 5. a second electrode (wing-shaped electrode), 51. a part of the second electrode, Sm. stepping motor, and Co. quartz resonator.