JP6412384B2 - Quartz crystal resonator, sensor head having the crystal resonator, film formation control device, and method for manufacturing film formation control device - Google Patents

Description

  The present invention relates to a crystal resonator whose oscillation frequency varies depending on the film thickness of a thin film formed on the crystal resonator, a sensor head having the crystal resonator, a film formation control device including an oscillator, and a film formation control device. It relates to the manufacturing method.

  In film formation processes such as vacuum evaporation, sputtering, and CVD, a film formation control device is used to control the film thickness on the substrate and the evaporation rate (deposition rate). As this film formation control apparatus, an apparatus that controls so as to perform stable film formation by measuring the film thickness of a thin film formed on a crystal resonator is known. Such a film formation control apparatus measures the film thickness of a substance by utilizing the fact that a resonance vibration (such as a secondary vibration, a sliding vibration, a bending vibration) changes when the substance adheres to the surface of the crystal resonator.

  For example, Patent Document 1 discloses a quartz crystal microbalance sensor device that uses an SC-Cut quartz resonator as a sensor head. This quartz microbalance sensor device has a problem with the AT-Cut quartz crystal resonator that has been used in the past, and reduces the influence on the oscillation frequency caused by exposure to high temperature in the deposition environment during deposition. Met.

JP 2006-292733 A

  When using an SC-Cut crystal unit, as described above, frequency fluctuations due to temperature in a high temperature environment can be suppressed as much as possible compared to using an AT-Cut crystal unit, and high-accuracy measurement can be performed. Met. However, Patent Document 1 merely discloses the use of an SC-Cut crystal resonator, and discloses a detailed configuration of the SC-Cut crystal resonator that can be accurately measured in the film forming process. Was not. Further, in a film forming apparatus such as a vacuum evaporation apparatus or a sputtering apparatus, a thin film is formed not only on a film forming target but also on a crystal resonator. When this thin film becomes thick, the resonance vibration of the crystal resonator becomes unstable or deviates from the frequency measurement range due to peeling of the evaporative substance film on the crystal resonator or accumulation of internal stress. However, Patent Document 1 does not consider these circumstances in the film forming apparatus.

  The present invention has been made in consideration of such circumstances, and a crystal resonator capable of performing film thickness measurement and film formation control with high accuracy even in a high temperature environment, a sensor head having the crystal resonator, and the sensor It is an object of the present invention to provide a film formation control device including a head and a method for manufacturing the film formation control device.

In order to solve the above-described problem, a crystal resonator according to the present invention is an SC-Cut crystal resonator used in a sensor for a film formation control device, and the crystal resonator is orthogonal to a crystal crystal axis. In the coordinate system X-axis, Y-axis, and Z-axis, θ is rotated about the Z-axis and φ is rotated about the X-axis, and the θ is 33 ° 30 ′ and the φ is 20 ° 25 ′ .
A sensor head according to the present invention includes the above-described crystal resonator and a holder for holding the crystal resonator.
Furthermore, a film formation control apparatus according to the present invention includes the sensor head in a sensor head of a vapor deposition apparatus, a sputtering apparatus, or a CVD (chemical vapor deposition) apparatus.
Furthermore, the method of manufacturing the film formation control apparatus according to the present invention includes a rotation angle θ around the Z axis and a rotation angle φ around the X axis in the orthogonal coordinate axes X-axis, Y-axis, and Z-axis that are crystal crystal axes. In a method of manufacturing a film forming control apparatus having a sensor head having a crystal resonator using a determined SC-Cut crystal plate, θ and φ are θ ₁ and φ ₁ , and the crystal plate is the θ The frequency difference between the reference temperature and the comparison temperature in the case of having ₁ and φ ₁ is defined as ΔF ₁ , three sets of (θ ₁ , φ ₁ , ΔF ₁ ) are determined, and the three sets of the above (θ ₁ , Φ ₁ , ΔF ₁ ), a step of obtaining a first equation θ ₁ x + φ ₁ y + ΔF ₁ z = 0 that is an equation of a plane, θ and φ are θ ₂ and φ ₂ , and the quartz plate is the thermal shock of a predetermined temperature on the surface of the crystal oscillator in the case with theta ₂ and phi ₂ Erareru before the maximum value of the difference frequencies in the while that added is defined as [Delta] F ₂ and three sets of _{(θ 2, φ 2, ΔF} 2) determining the three sets of the (theta _2, phi ₂ , ΔF ₂ ), a step of obtaining a second equation θ ₂ x + φ ₂ y + ΔF ₂ z = 0, which is a plane equation passing through, and simultaneously setting z = 0 in the first equation and the second equation x And y, and a step of incorporating a quartz crystal resonator having a quartz plate with the obtained x and y being θ and φ, respectively, into the sensor head.

  In the crystal resonator according to the present invention, the sensor head having the crystal resonator, the film formation control device, and the method for manufacturing the film formation control device, the film thickness measurement and film formation control are subject to frequency fluctuations due to temperature in a high temperature environment. Can be performed with high accuracy.

1 is a schematic configuration diagram of a vacuum vapor deposition apparatus to which a sensor head having a crystal resonator and a film formation control apparatus in this embodiment can be applied. The graph which shows the frequency-temperature characteristic of an AT-Cut crystal resonator. The graph which compared the frequency-temperature characteristic of the AT-Cut crystal resonator with the film thickness (oscillation frequency) of the formed Al thin film. The graph which shows the time change of the frequency at the time of giving a thermal shock so that it may become predetermined temperature on the surface of an AT-Cut crystal resonator. The graph which compared the time change of the frequency at the time of giving a thermal shock so that it may become predetermined temperature on the surface of an AT-Cut crystal oscillator by the film thickness (oscillation frequency) of the formed thin film. The graph which compared the frequency-temperature characteristic of the SC-Cut crystal oscillator with the film thickness (oscillation frequency) of the formed Al thin film. The graph which compared the time change of the frequency at the time of giving a thermal shock so that it may become predetermined temperature on the surface of a SC-Cut crystal oscillator by the film thickness (oscillation frequency) of the formed thin film. The graph which compared the time change of the oscillation frequency of a crystal oscillator with the film-forming apparatus provided with the sensor head using an AT-Cut crystal oscillator, and the film-forming apparatus provided with the sensor head using an SC-Cut crystal oscillator. . The graph which compared the time-dependent change of the vapor deposition rate with the film-forming apparatus provided with the sensor head using an AT-Cut crystal oscillator, and the film-forming apparatus provided with the sensor head using an SC-Cut crystal oscillator. The graph which compared the time change of the power supply output with the film-forming apparatus provided with the sensor head using an AT-Cut crystal resonator, and the film-forming apparatus provided with the sensor head using an SC-Cut crystal resonator. The schematic block diagram of the sputtering device to which the film-forming control apparatus in this embodiment is applied.

  An embodiment of a crystal resonator according to the present invention, a film formation control device including a sensor head having the crystal resonator, and a method of manufacturing the film formation control device will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a vacuum vapor deposition apparatus to which a sensor head having a crystal resonator and a film formation control apparatus according to this embodiment can be applied.

  The crystal resonator in this embodiment is applied to a vacuum vapor deposition apparatus 1 as shown in FIG. The vacuum evaporation apparatus 1 is used for forming a film on a semiconductor, a metal film for an electrode, an organic EL film, or the like. The vacuum deposition apparatus 1 is configured such that an evaporation source 11 for evaporating a film forming material, a film forming target 12, and a film forming material are vaporized with respect to the film forming target 12 before the film forming process. And a shutter mechanism 13 for blocking steam. The vacuum deposition apparatus 1 also includes a crystal oscillation type film formation control apparatus 2 as a film formation control apparatus.

  The film formation control device 2 includes a sensor head 14, an oscillator 15, and a film thickness meter 16. The sensor head 14 (film thickness measuring device) has an SC-Cut crystal resonator held by a holder. The crystal resonator includes a crystal plate and an electrode that is provided on the crystal plate and applies a voltage. Various metal materials such as gold and silver can be applied to the electrodes. The crystal resonator detects the film thickness by vibrating according to the film thickness of the film forming material attached to the surface. The crystal resonator has a resonance frequency of 2 M to 30 MHz, for example. The oscillator 15 oscillates at the resonance frequency of the crystal resonator, and outputs the measured oscillation frequency change of the crystal resonator to the film thickness meter 16 as an electrical signal. The film thickness meter 16 calculates the film thickness of the film formation target 12 and the current vapor deposition rate based on the electrical signal from the oscillator 15, and outputs an appropriate power instruction value to the evaporation source power source 17 to be set. A feedback signal is output so that the deposition rate becomes high. The evaporation source power supply 17 outputs required power to the evaporation source 11 based on the output of the film formation control device 2.

  Details of the sensor head 14 will be described below. The sensor head 14 in the present embodiment realizes film formation control (film thickness measurement) that suppresses frequency fluctuation due to temperature in a high temperature environment, compared to a sensor head having a conventionally used AT-Cut crystal resonator. can do. First, for comparison, a problem of a sensor head (deposition control device) using an AT-Cut crystal resonator will be described. The AT-Cut crystal resonator used for the following comparison was cut so that the rotation angle θ around the Z axis of the Cartesian coordinate system X-axis, Y-axis, and Z-axis is 3 ° 05 ′. It has been done.

  FIG. 2 is a graph showing frequency-temperature characteristics of the AT-Cut crystal resonator.

  The AT-Cut crystal resonator has a good frequency-temperature characteristic from 20 ° C. to 70 ° C. with an inflection point of 25 ° C. However, when a thin film is formed on the quartz resonator by being repeatedly used in the film forming process, the frequency-temperature characteristics change.

  Here, FIG. 3 is a graph comparing the frequency-temperature characteristics of the AT-Cut crystal resonator with the film thickness (oscillation frequency) of the formed Al thin film. FIG. 3 shows frequency-temperature characteristics when the thin film is not formed (new) and when the oscillation frequency changes stepwise as a result of forming the thin film. Further, in FIG. 3, each line is represented for each output frequency (5.00 MHz (new, no thin film), 4.903 MHz, 4.804 MHz, 4.694 MHz) of the oscillator which decreases depending on the film thickness, and is a graph. The Y axis of shows the temperature drift frequency (Hz). Note that the phenomenon in which the frequency-temperature characteristics of the quartz crystal resonator greatly change when the deposited film is formed in this way is a fact discovered by repeated experiments by the present inventors.

  When an Al thin film, which is a film forming material, adheres to the crystal unit, the oscillation frequency of the crystal unit changes. That is, the frequency-temperature characteristic has a downward slope according to the amount of thin film formed. Conventionally, an example has been disclosed in which the accuracy of the measurement result is improved by correcting the frequency-temperature characteristic according to the temperature of the sensor head using the AT-Cut crystal resonator. However, if the thin film adheres to the quartz resonator and the frequency-temperature characteristic becomes large in this way, even if correction is made according to the temperature, it will be out of the frequency correction range and appropriate measurement cannot be performed. . For this reason, the conventional film thickness control device cannot perform sufficient measurement.

  FIG. 4 is a graph showing a time change in frequency when a thermal shock is applied to the surface of the AT-Cut crystal resonator so as to reach a predetermined temperature. The Y axis of the graph indicates the temperature drift frequency (Hz) (the same applies to FIGS. 5 to 7). The thermal shock applied to the AT-Cut crystal resonator was radiant heat from a 30 W halogen lamp (the same applies to FIGS. 5 and 7). In the electron beam evaporation apparatus, when the AT-CUT quartz resonator 3 ° 05 ′ is used, the frequency change due to radiant heat when the shutter is opened may be about 200 Hz at the maximum, and the surface temperature of the quartz resonator may be about 50 ° C. I found it experimentally. For this reason, a change corresponding to 200 Hz, that is, a situation corresponding to a surface temperature of 50 ° C. was made using a halogen lamp with an output of 30 W.

  When a sensor head using an AT-Cut crystal resonator is combined with an oscillator, a thermal shock is suddenly applied to the sensor head by the radiant heat of the evaporation source when the shutter is opened by the shutter mechanism. As a result, the output frequency from the oscillator rapidly increases without following the frequency-temperature characteristics. The occurrence of "thermal shock" is caused by internal stress on the crystal unit due to the difference in thermal expansion coefficient between the crystal unit made of silicon dioxide and the metal material for electrodes such as gold and silver. I found out through experiments.

  FIG. 5 is a graph comparing the time variation of the frequency when the thermal shock is applied to the surface of the AT-Cut crystal resonator so as to reach a predetermined temperature by the film thickness (oscillation frequency) of the formed thin film. In FIG. 5, each line indicates an oscillator output frequency that decreases depending on the film thickness (5.00 MHz (new, no thin film), 4.970 MHz, 4.900 MHz, 4.845 MHz, 4.804 MHz, 4.743 MHz. 4.695 MHz).

  When a thin film is formed on the crystal resonator, it can be seen that the frequency variation varies according to the oscillation frequency of the AT-Cut crystal resonator as shown in FIG. As a result, correction is difficult as in the frequency-temperature characteristics, and the controllability of the deposition rate, which is the film formation rate, and the accuracy of film thickness measurement are reduced. For this reason, as with the frequency-temperature characteristics, even when correction is performed in a state where no thin film is formed, variation occurs as the thin film is formed, and accurate measurement and control cannot be performed.

  On the other hand, the sensor head using the SC-Cut crystal resonator is stable without being affected by frequency-temperature characteristics and frequency changes due to thermal shock even when a thin film is formed on the surface. Film thickness measurement and deposition rate control can be performed.

  FIG. 6 is a graph comparing the frequency-temperature characteristics of the SC-Cut crystal resonator with the film thickness (oscillation frequency) of the formed Al thin film. In FIG. 6, each line is represented for each output frequency (5.00 MHz (new, no thin film), 4.90 MHz, 4.80 MHz, 4.70 MHz) of the oscillator that decreases depending on the film thickness.

  FIG. 7 is a graph comparing the time variation of the frequency when the thermal shock is applied to the surface of the SC-Cut crystal resonator so as to reach a predetermined temperature by the film thickness (oscillation frequency) of the formed thin film. In FIG. 7, each line is represented for each output frequency of the oscillator (5.00 MHz (new, no thin film), 4.97 MHz, 4.90 MHz, 4.80 MHz, 4.70 MHz) that decreases depending on the film thickness. The

  The SC-Cut crystal resonator used for the description has a rotation angle θ around the Z axis of the crystal crystal axes X, Y, and Z of 34 ° and a rotation angle φ around the X axis of 22 ° 30 ′. It was cut to become.

  As shown in FIG. 6, in the SC-Cut crystal resonator, when a thin film is not formed (5.00 MHz) and a thin film is formed most (4.70 MHz), the maximum is about 40 Hz. Only changes. This is about 1/10 of the change in the frequency of the AT-Cut crystal resonator, and even if the film thickness is increased, that is, even if the film forming process is repeated a plurality of times, the frequency-temperature of the crystal resonator. Indicates that the characteristic does not change.

  Similarly, the time change of the frequency with respect to the thermal shock shown in FIG. 7 also changes only about 40 Hz at the maximum, and the change is small as compared with the AT-Cut crystal resonator. That is, the SC-Cut crystal resonator has little change in both frequency-temperature characteristics and frequency change due to thermal shock regardless of the film thickness, and even when the film forming process is repeated a plurality of times, measurement with a small error can be performed. Can be maintained. As a result, the film formation control apparatus using the SC-Cut crystal resonator as the sensor head can perform suitable vapor deposition rate control.

  Next, a method for determining the cut angle of the SC-Cut crystal resonator, that is, a method for manufacturing the film formation control apparatus will be described.

  As described above, in the SC-Cut crystal resonator, the change in the frequency-temperature characteristic according to the film thickness and the change in the frequency with respect to the thermal shock do not change according to the film thickness as compared with the AT-Cut crystal resonator. For this reason, in order to minimize the frequency change due to the frequency-temperature characteristics and thermal shock when the film thickness is gradually increased by repeating the film forming process and forming a thin film on the crystal resonator, What is necessary is to minimize the frequency change due to the frequency-temperature characteristics and thermal shock when the thin film is not formed.

  In the present embodiment, a film formation control device is obtained by obtaining θ and φ of an SC-Cut crystal resonator capable of minimizing frequency changes due to frequency-temperature characteristics and thermal shock when no thin film is formed. The configuration of the SC-Cut crystal resonator suitable for the above was determined.

  Specifically, an SC-Cut crystal resonator having θ and φ that has a frequency-temperature characteristic of ± 10 ppm or less when the temperature of the crystal resonator is 20 to 65 ° C. (condition 1). Alternatively, the SC having θ and φ in which the change in frequency when applied to the surface of the thermal shock crystal resonator with respect to the frequency before the thermal shock of 50 ° C. or less is applied to the surface of the crystal resonator is ± 10 ppm or less. -Cut crystal resonator (condition 2). It is assumed that the crystal resonator rotates θ around the Z axis and rotates φ around the X axis in the orthogonal coordinate system X-axis, Y-axis, and Z-axis that are crystal crystal axes. The crystal resonator may satisfy either one of the above conditions 1 and 2, or may satisfy both.

Specifically, the rotation angle θ around the Z axis and the rotation angle φ around the X axis are defined as θ ₁ and φ ₁ , respectively. The frequency - relates temperature characteristics, the frequency difference between the reference temperature and compared temperature when crystal oscillator having a theta ₁ and phi ₁ is defined as [Delta] F _1. Next, three sets of (θ ₁ , φ ₁ , ΔF ₁ ) are determined. Further, a first equation θ ₁ x + φ ₁ y + ΔF ₁ z = 0, which is a plane equation passing through three sets of (θ ₁ , φ ₁ , ΔF ₁ ), is obtained.

Also, θ and φ are defined as θ ₂ and φ ₂ . And, the maximum value of the difference of frequency in a while on the surface of the crystal oscillator having a theta ₂ and phi ₂ thermal shock at a predetermined temperature is added to the previous applied is defined as [Delta] F _2. Next, three sets of (θ ₂ , φ ₂ , ΔF ₂ ) are determined. Further, a second equation θ ₂ x + φ ₂ y + ΔF ₂ z = 0, which is a plane equation passing through three sets of (θ ₂ , φ ₂ , ΔF ₂ ), is obtained.

Next, in the first expression and the second expression, x and y are obtained by setting z = 0 simultaneously. That is, θ and φ when the frequency changes ΔF ₁ and ΔF ₂ due to frequency-temperature characteristics and thermal shock are 0 are obtained. Then, an SC-Cut crystal resonator having a rotation angle θ around the Z axis and a rotation angle φ around the X axis based on the obtained x and y is incorporated into the sensor head, thereby manufacturing the film formation control apparatus.

  Furthermore, the range of θ and φ in which the change in frequency due to the frequency-temperature characteristics and the thermal shock is ± 10 ppm or less is also obtained based on the first and second expressions. This makes it possible to obtain θ and φ that are suitable for frequency change due to frequency-temperature characteristics and thermal shock, and to provide a sensor head having a crystal resonator with excellent measurement accuracy by suppressing frequency fluctuation due to temperature in a high temperature environment. The film formation control apparatus provided can be manufactured.

  Hereinafter, a specific example will be described. The oscillation frequency of the SC-Cut crystal resonator is 5 MHz.

In order to obtain the first equation θ ₁ x + φ ₁ y + ΔF ₁ z = 0, three sets of (θ ₁ , φ ₁ , ΔF ₁ ) were obtained as follows. For θ ₁ and φ ₁ , numerical values were arbitrarily selected with reference to θ = 34 ° and φ = 22 ° 30 ′ as a reference. ΔF ₁ was obtained by measuring using an SC-Cut crystal resonator having each θ ₁ and φ ₁ . ΔF ₁ was a frequency change at a comparative temperature of 65 ° C. with respect to a reference temperature of 20 ° C. (frequency change at 20 to 65 ° C.).

(Θ ₁ , φ ₁ , ΔF ₁ ) = (33 ° 40 ′, 23 ° 20 ′, −75),
(33 ° 40 ', 24 ° 00', -82),
(33 ° 50 ', 24 ° 00', -147)

The formula of the plane passing through the three points was as follows.
[Equation 1]
−108.55x−1.12y−0.2672z−3659.85 = 0 (1)

Further, in order to obtain the second equation θ ₂ x + φ ₂ y + ΔF ₂ z = 0, three sets (θ ₂ , φ ₂ , ΔF ₂ ) were obtained as follows. θ ₂ and φ ₂ were set to the same values as θ ₁ and φ ₁ . ΔF ₂ was obtained by measuring using an SC-Cut crystal resonator composed of θ ₂ and φ ₂ . The thermal shock was set so that the surface temperature of the crystal unit was 50 ° C. by using a 30 W halogen lamp. That is, ΔF ₂ is a frequency change when a thermal shock is applied to the surface of the crystal resonator with respect to a frequency before the thermal shock of 50 ° C. or less is applied.

(Θ ₂ , φ ₂ , ΔF ₂ ) = (33 ° 40 ′, 23 ° 20 ′, −33),
(33 ° 40 ', 24 ° 00', -51),
(33 ° 50 ', 24 ° 00', -63)

The formula of the plane passing through the three points was as follows.
[Equation 2]
-20.04x-2.88y-0.2672z + 730.24 = 0 (2)

Next, x and y when z = 0 are obtained. That is, θ and φ when the frequency changes ΔF ₁ and ΔF ₂ are 0 are obtained. As a result, (θ, φ) = (33 ° 30 ′, 20 ° 25 ′) was obtained.

Next, the range of θ and φ in which the frequency-temperature characteristic is ± 10 ppm and the frequency change due to thermal shock is ± 10 ppm is obtained. In the case of a 5 MHz crystal resonator, ΔF ₁ and ΔF ₂ may be ± 50 Hz in order to obtain ± 10 ppm. Therefore, θ and φ when ΔF ₁ and ΔF ₂ are the following combinations are obtained by the above formulas (1) and (2). The results are as follows.

In the case of (ΔF ₁ , ΔF ₂ ) = (50, 50), (θ, φ) = (33 ° 26 ′, 16 ° 20 ′)
In the case of (ΔF ₁ , ΔF ₂ ) = (50, −50), (θ, φ) = (33 ° 19 ′, 26 ° 20 ′)
In the case of (ΔF ₁ , ΔF ₂ ) = (− 50, 50), (θ, φ) = (33 ° 41 ′, 14 ° 29 ′)
When (ΔF ₁ , ΔF ₂ ) = (− 50, −50), (θ, φ) = (33 ° 35 ′, 24 ° 29 ′)

As a result, the range of θ and φ where the frequency change is ± 10 ppm or less is (θ, φ) = (33 ° 30 ′ ± 11 ′, 20 ° 25 ′ ± 6 °)
It becomes. When (θ, φ) = (33 ° 30 ′, 20 ° 25 ′), the temperature drift frequency of the SC-Cut crystal resonator can be minimized.

  As described above, the crystal resonator according to the present embodiment, the sensor head having the crystal resonator, the film formation control device, and the film formation control device manufactured by the method for manufacturing the film formation control device have a frequency even if a thin film is formed. -By utilizing the characteristics of the SC-Cut crystal resonator that changes in temperature characteristics and frequency changes due to thermal shock are small, it is possible to measure the film thickness and control the evaporation rate with high accuracy while suppressing frequency fluctuations due to temperature in high temperature environments It becomes possible.

  Further, in the method of manufacturing the film formation control apparatus according to the present embodiment, in an SC-Cut crystal resonator in which no thin film is formed, θ and φ excellent in frequency-temperature characteristics and frequency change due to thermal shock are approximated and obtained. It was. Thereby, even when a thin film is formed, highly accurate film thickness measurement and evaporation rate control can be realized as in the case where a thin film is not formed.

  Further, as shown in FIGS. 8 to 10 below, the film formation control device including the sensor head using the SC-Cut crystal resonator is the film formation control device including the sensor head using the AT-Cut crystal resonator. Control is possible with higher accuracy than

  FIG. 8 shows a temporal change in the oscillation frequency of a crystal resonator between a film forming apparatus having a sensor head using an AT-Cut crystal resonator and a film forming apparatus having a sensor head using an SC-Cut crystal resonator. It is the graph which compared.

  FIG. 9 is a graph comparing the time variation of the deposition rate between a film forming apparatus having a sensor head using an AT-Cut crystal resonator and a film forming apparatus having a sensor head using an SC-Cut crystal resonator. It is.

  FIG. 10 is a graph comparing power output changes over time in a film forming apparatus including a sensor head using an AT-Cut crystal resonator and a film forming apparatus including a sensor head using an SC-Cut crystal resonator. It is.

  8 to 10 show an example in which a low-rate film is formed by opening the closed shutter when 250 seconds have elapsed. In the case of a sensor head using an AT-Cut crystal resonator, the output of the power supply gradually increases, so that the crystal resonator and the sensor head drift due to radiant heat even when the shutter is closed. When is opened, the oscillation frequency of the crystal resonator is shifted to the higher side due to thermal shock. On the other hand, in the case of a sensor head using an SC-Cut crystal resonator, it can be seen that there is almost no influence of temperature drift and thermal shock even under the same conditions.

  Thus, the film forming apparatus including the sensor head using the SC-Cut crystal resonator includes the sensor head using the AT-Cut crystal resonator in the frequency change, the deposition rate change, and the power output change. The film forming process can be controlled without being affected by the temperature in a higher temperature environment.

  In addition, although the film-forming control apparatus in this embodiment demonstrated the vacuum evaporation system as an example, you may apply to a sputtering device or a CVD apparatus.

  FIG. 11 is a schematic configuration diagram of a sputtering apparatus to which the film formation control apparatus according to this embodiment is applied.

  The sputtering apparatus 21 arranges a substrate 32 and a target electrode 33 formed in accordance with the composition of the film forming material in a vacuum chamber 31 so as to face each other. In the vacuum chamber 31, a plasma atmosphere 35 is formed by applying a predetermined power from a high-frequency power supply 34 to cause glow discharge. The sputtering apparatus 21 accelerates and collides ions of a rare gas ionized in the plasma atmosphere 35 toward the target, and sputters particles (target atoms) generated thereby are deposited and deposited on the substrate surface. Thereby, the sputtering apparatus 21 forms a thin film.

  Such a sputtering apparatus 21 includes a film formation control apparatus 22 including a sensor head 36, an oscillator 37, and a film thickness meter 38, as in the vacuum vapor deposition apparatus illustrated in FIG. 1. In addition, an impedance matching unit 39 for matching impedance between the high frequency power supply 34 and the target electrode 33 is provided.

  Such a sputtering apparatus 21 and a CVD apparatus are exposed to plasma and thus have a high temperature and require water cooling. However, the sensor head provided with the SC-Cut crystal resonator in this embodiment has less temperature drift than the AT-Cut crystal resonator. For this reason, the sensor head in the present embodiment can be suitably used for the sputtering apparatus 21 and the CVD apparatus.

  Note that the SC-Cut crystal resonator can be reused by being used in the film forming process, and then removing the formed thin film and electrode and forming the electrode again.

DESCRIPTION OF SYMBOLS 1 Vacuum evaporation apparatus 2 Film formation control apparatus 10 Vacuum tank 11 Evaporation source 12 Film formation target 13 Shutter mechanism 14 Sensor head 15 Oscillator 16 Film thickness meter 17 Evaporation source power source 21 Sputtering apparatus 22 Film formation control apparatus 31 Vacuum tank 32 Substrate 33 Target electrode 34 High frequency power source 35 Plasma atmosphere 36 Sensor head 37 Oscillator 38 Film thickness meter 39 Impedance matching device

Claims (5)

An SC-Cut crystal resonator used in a sensor for a film formation control device,
The crystal resonator is a crystal crystal axis that is rotated by θ around the Z axis in the Cartesian coordinate system X-axis, Y-axis, and Z-axis and φ-rotated around the X-axis, and the θ is 33 ° 30 ′, A crystal resonator in which the φ is 20 ° 25 ′ . The crystal resonator according to claim 1 ;
And a holder for holding the crystal unit. A film formation control apparatus comprising the sensor head according to claim 2 on a sensor head of a vapor deposition apparatus, a sputtering apparatus, or a CVD (chemical vapor deposition) apparatus. It has a crystal resonator using an SC-Cut crystal plate determined by a rotation angle θ around the Z axis and a rotation angle φ around the X axis in the orthogonal coordinate system X axis, Y axis, and Z axis that are crystal crystal axes. In the manufacturing method of the film formation control apparatus provided with the sensor head,
When θ and φ are θ ₁ and φ ₁ and the crystal plate has θ ₁ and φ ₁ , the frequency difference between the reference temperature and the comparison temperature is defined as ΔF _1, and three sets of ( theta _1, phi _1, [Delta] F ₁₎ to determine the three sets of the (theta _1, phi _1, and obtaining a first expression _{θ 1 x + φ 1 y +} ΔF 1 z = 0 is the equation of a plane passing through the [Delta] F ₁₎ ,
When θ and φ are θ ₂ and φ ₂ and the quartz plate has θ ₂ and φ ₂ and before the thermal shock of a predetermined temperature is applied to the surface of the crystal resonator, 3 pairs of the maximum value of the difference in frequency is defined as [Delta] F ₂ in the _{(θ 2, φ 2, ΔF} 2) determining the three sets of the _{(θ 2, φ 2, ΔF} 2) of a plane passing through the Obtaining a second equation θ ₂ x + φ ₂ y + ΔF ₂ z = 0, which is an equation;
Obtaining x and y by simultaneously setting z = 0 in the first formula and the second formula;
And a step of incorporating a crystal resonator having a crystal plate in which the obtained x and y are respectively θ and φ into the sensor head. Obtaining the range of θ and φ based on the first and second formulas such that the frequency change due to frequency-temperature characteristics and thermal shock is ± 10 ppm or less;
The method of manufacturing a film forming control apparatus according to claim 4 , further comprising a step of incorporating a crystal resonator having a crystal plate having the θ and φ within the determined range of θ and φ into the sensor head.

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