JP2000212732A - Vacuum vapor deposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum vapor deposition device which is capable of continuously and uniformly forming a mixture film consisting of different elements and having a prescribed composition ratio and target thickness on a traveling film surface. SOLUTION: A vacuum vapor deposition device comprises a crucible 9 capable of holding vapor deposition materials of different kinds, an electron beam gun 4 to heat the vapor deposition materials for vapor deposition, an X-ray generator 7a to irradiate the mixture film on a film 18 formed by the electron beam gun 4 with the X-ray, a semi-conductor detector 7b to measure the intensity of the characteristic X-ray excited by the X-ray generator 7a, and a measuring means to output the thickness data for each composition of the mixture film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum deposition apparatus suitable for producing various film products, and more particularly to a vacuum deposition apparatus for forming a mixed film of different elements on a film running in a vacuum chamber.

[0002]

2. Description of the Related Art As a method of depositing and shaping a thin film on a polymer film running in a vacuum chamber, for example, Japanese Patent Application Laid-Open No.
There is a method described in 6273. In this method, a horizontally elongated evaporation source facing and disposed across the width of the polymer film in a direction perpendicular to the moving polymer film is irradiated with an electron beam from a non-scanning electron gun and heated. A thin film is formed on a molecular film. When irradiating the electron beam from the electron gun, the magnetic field is controlled so that the electron beam has the same incident angle at each position of the evaporation source.

However, in this method, since there is no means for monitoring the thickness of the deposited film, for example, when the deposition rate changes due to a change in the degree of vacuum in the vacuum chamber or a change in the surface shape of the deposition material, There is a problem that the thickness of the deposited film varies and is not constant. In addition, this method cannot form a mixed film of these vapor deposition materials on a polymer film by simultaneously vapor depositing a plurality of vapor deposition materials.

[0004] As a vacuum evaporation apparatus invented to solve such a problem, for example, a detector for detecting a part of the evaporation amount when an evaporation source in a vacuum chamber is heated by an electron gun, and a detector for detecting a part of the evaporation amount. And means for controlling the output of the evaporation source based on the detected value of the above. This type of detector is provided with a crystal oscillator, and utilizes the principle that, when a deposited film adheres to the crystal oscillator, the oscillation frequency varies depending on the film thickness. This vacuum evaporation apparatus indirectly controls the thickness of a thin film formed on a polymer film using a part of the evaporation amount from an evaporation source as a control index.

[0005] However, when the above-described detector has a plurality of different types of vapor deposition sources, the detected signal cannot be decomposed into information on each component, and as a result, the chemical composition ratio and the control of the thickness are not controlled. There is a problem that the accuracy is significantly reduced. In addition, due to indirect control, for example, when the direction of the evaporation beam at the time of vapor deposition is changed, the measured value of the detector may not match the actually measured value. Furthermore, the above-mentioned detector requires measures such as switching the detector during measurement when performing long-term continuous measurement due to the limitation of the total deposition amount on the detector, and there is a problem in the reliability of the measurement. For example, Japanese Patent Application Laid-Open No. Hei.
There is an apparatus described in Japanese Patent Publication No. 5 (JP-A) No. 5 (1994). This apparatus includes an electron gun for exciting an characteristic X-ray by injecting an electron beam at an acute angle into a vapor-deposited film on a substrate after vapor deposition, a detector for measuring the characteristic X-ray intensity, and a detector for measuring the characteristic X-ray intensity. Means for controlling the output of each deposition source based on the detected value. This apparatus can directly measure a vapor-deposited thin film, so that film forming properties are improved as compared with the above-described apparatus.

[0006] However, the characteristic X-ray is RHEED
Since (high-energy electron beam) is excited by being incident on the vapor-deposited film at an acute angle, only information on the very surface layer of the vapor-deposited thin film can be obtained. That is, since information on the entire vapor-deposited thin film cannot be obtained, sufficient information cannot be obtained as an apparatus for producing a vapor-deposited film having a constant composition ratio and total thickness of the mixed film. Further, since the excitation source of the characteristic X-ray is a high energy electron beam, there is also a problem that the irradiated film surface at the irradiated portion is damaged.

[0007]

As described above, in the conventional apparatus, a mixed film composed of two kinds of components is uniformly dispersed and formed in the width direction and the running direction of the running film, and has a constant composition ratio and a constant thickness. Therefore, it is difficult to form continuously and stably for a long time.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to form a mixed film comprising different elements on a running film surface and having a predetermined composition ratio and a target thickness continuously and in a desired manner. An object of the present invention is to provide a vacuum deposition apparatus that can be formed uniformly. In the present invention, "film"
The term “collectively” refers to a material having a thin shape with respect to the width and the length, and is used as a concept including not only an original film but also a sheet material.

[0009]

The above object is achieved by the invention described in the claims. That is, the characteristic configuration of the vacuum deposition apparatus according to the present invention is such that a holding film capable of forming a mixed film made of different elements on a film traveling in a vacuum chamber and holding different types of deposition materials, Heating means for heating and steaming the material; and X-rays for irradiating the mixed film on the film formed by the heating means with X-rays.
X-ray irradiating means, a semiconductor detector for measuring the intensity of characteristic X-rays excited by the X-ray irradiating means, and a measuring means for outputting thickness data for each component of the mixed film. .

[0010] According to this configuration, the characteristic X-ray intensity of each component is directly and in real time obtained from the mixed film formed on the running film by the vaporized components evaporated from the different types of vapor deposited materials held by the holding means. Can be converted and output as thickness data of each mixed film forming component from the measured value, and based on this thickness data, for example, a comparison is made with a target value of each component preset by a separately provided control means. , It is possible to perform processing such as obtaining these deviation values. By doing so, it becomes possible to perform feedback control of the heating means based on such processing, and a mixed film having a predetermined chemical composition and a desired thickness can be formed into a film with high accuracy. In addition, since the X-rays are irradiated to detect the thickness data of the vapor-deposited mixed film forming components, unlike the irradiation with the high energy electron beam, the mixed films are not damaged. Further, since a semiconductor detector is used, the entire apparatus can be made compact, and even if a plurality of detectors are arranged, it does not occupy a large space, and high-precision measurement can be performed in the film width direction. As a result, a mixed film having a composition ratio and a target thickness of a mixed film of different elements is continuously formed on the running film surface,
In addition, a vacuum evaporation apparatus that can be formed uniformly can be provided.

The X-ray irradiating means preferably irradiates the mixed film whose thickness is to be measured substantially perpendicularly. By doing so, the characteristic X-ray to be excited can be conveniently obtained as information in the entire thickness direction of the mixed film. Here, “substantially perpendicular” is used as a concept that includes not only vertical in a strict sense in measurement but also an approximate posture thereof.

The thickness monitoring devices comprising the X-ray irradiating means and the detector are arranged in a zigzag manner at substantially equal intervals in the film width direction, or are arranged at substantially equal intervals in a row in the film width direction. Preferably. When the thickness monitor devices are arranged in a staggered manner, it is difficult to be restricted by the shape of the thickness monitor device, so that a large amount of thickness information can be simultaneously and accurately measured in real time over the entire width of the mixed film, which is convenient.
In addition, when the thickness monitor devices are arranged at substantially equal intervals in a line in the film width direction, the number of devices can be reduced, the configuration can be made relatively inexpensively, and almost the entire width of the mixed film can be measured simultaneously and in real time. convenient. Moreover, in the above-described manner, even when a plurality of thickness monitors are arranged facing each other in the film width direction, the mixed film whose thickness is to be measured can be irradiated with X-rays substantially perpendicularly. Here, the term “substantially equal intervals” is used as a concept including not only equal intervals in a strict sense in terms of measurement but also a slight shift in intervals.

It is preferable that the apparatus further comprises a control means for automatically controlling the heating means based on the thickness data output from the measuring means. In this case, by controlling the heating means in accordance with the output thickness data, a desired thickness can be formed over the entire width and length of the film, which is convenient.

It is preferable that the control means includes an arithmetic means for approximately predicting thickness data of a deposited film between the thickness monitor devices based on thickness data measured by a plurality of thickness monitor devices. In this case, the thickness between the measurement points is approximately predicted based on the measured information,
The controllability is further improved, and the control can be performed with high accuracy even with a particularly small thickness monitor arrangement, which is convenient.

[0015]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic structure of a vacuum evaporation apparatus according to the present embodiment. In this vacuum evaporation apparatus, a polymer film such as polyethylene terephthalate (PET) was used as an example of a film-shaped material to be evaporated. The polymer film 18 set on the unwinding roll 1 of the vacuum chamber 6 travels on the cooling roll 3, passes through the measuring roll 5, and is wound by the winding roll 2. The degree of vacuum in the vacuum chamber 6 is controlled by an exhaust system 10 such as an oil diffusion pump (not shown).
Maintains a predetermined degree of vacuum. FIG. 8 shows a shielding plate for forming a uniform and good deposited film on the material to be deposited.

At the bottom of the vacuum chamber 6, a crucible 9 as an example of holding means for holding the vapor deposition material 16 is arranged. The crucible 9 is moved toward an electron gun 4 as an example of a heating means. It moves at a low speed while maintaining an equilibrium relationship with the surface to be deposited. That is, the crucible 9 is moved closer to or away from the electron gun 4 in FIG. 1 so that the vapor deposition conditions are kept constant with respect to the moving polymer film. Irradiation conditions (e.g. distance between electron gun and electronic material)
Are arranged to be as constant as possible. The electron gun 4 irradiates an electron beam 19 to the vapor deposition material 17 stored in the crucible 9. A part of the evaporation material heated and evaporated by the electron beam 19 is evaporated on the surface of the polymer film 18 running on the cooling roll 3.

Next, a description will be given of a thickness monitoring device 7 arranged above the vacuum chamber 6 for measuring the thickness of a thin film deposited on the surface of the polymer film 18. An X-ray generator 7 a for exciting characteristic (fluorescent) X-rays from the film constituent components is arranged in the monitor device 7 substantially perpendicular to the measurement roll 5. From the X-ray generator 7a, the minus part of the characteristic X-rays excited by the X-rays emitted substantially perpendicularly to the vapor-deposited polymer film 18 traveling on the measurement roll 5 is 30 It is guided to the Si (Li) semiconductor (lithium semiconductor to which silicon is added) detector 7b arranged at an angle of °. In the semiconductor detector 7b,
A weak current pulse is generated in proportion to the energy of the incident characteristic X-ray. This current pulse is converted by the preamplifier 11 into a voltage pulse proportional to the amount of the current pulse. Further, after being amplified by the amplifier 12, the wave height analyzer 13
, An energy spectrum is formed. The characteristic X-ray intensity converted into the energy spectrum is converted into the thickness of each element by the thickness calculator 14 and then input to the control amount calculator 15. Here, the thickness monitor 7, the preamplifier 11, the amplifier 12, the wave height analyzer 13, and the thickness calculator 14 constitute online thickness measuring means.

The control amount calculator 15 compares the previously set target reference thickness data of each element with the input measured thickness data to determine a deviation value. Based on the obtained deviation value information, control data for automatically controlling the electron gun is automatically generated. This control data is sent to the electron gun controller 16. The electron gun controller 16 controls the power supplied to the electron gun 4 and the scanning time of the electron beam according to the input control data. Here, the control amount calculator 15 and the electron gun controller 16 constitute control means.

[0019]

The following is an example of the actual operation.

Example 1 A polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., E5100: trade name) was used as the polymer film 18 to be deposited. Other polymer films that can be used include polypropylene, polyethylene, nylon 6, nylon 6
6, nylon 12, nylon 4, polyvinyl chloride, polyvinylidene chloride, etc., but the polymer film is not particularly limited to materials.

The evaporation material (evaporation source) as aluminum oxide in which the 3~5mm about the size of the particulate (Al ₂ 0
₃ , purity 99.5%) and silicon oxide (SiO ₂ , purity 9)
9.9%). One crucible for holding these materials is made of copper, and has a structure in which a cooling water cooling tube 21 having an outer diameter of 20 mmΦ is provided at the bottom. The flow rate of the cooling water is approximately 4 m ³ . In this crucible 9, 2 mm-thick carbon stripping plates 20 are arranged at intervals of 100 mm in the width direction in order to alternately arrange the vapor deposition materials in a line opposite to the film width direction, and a total of 8 blocks of material are stored. A structure that can be used. The threshold plate 20 is arranged to be inclined at an angle substantially equal to an angle at which an electron beam 19 of the electron gun 4 described later is incident on each deposition material. The two types of vapor deposition materials were alternately and uniformly accommodated in each block secured by the partition plate 20. 2 and 3 show a schematic structure of the crucible 9 used in this embodiment.

As the electron gun 4, a 250 kW electron gun was arranged so as to face a crucible 9 arranged in parallel with the film width direction. The electron gun 4 provided a total of 8 blocks of SiO _{2 and} 4 blocks of Al ₂ O ₃ alternately arranged in the crucible.
It was designed to deposit the deposition material of the block. In this embodiment, one electron gun is used. However, when the total amount of energy to be charged into the crucible 9 cannot be secured by one unit or when a wide polymer film is deposited, a plurality of electron guns are used. Thus, a method of dividing the deposition region may be adopted, and the number of electron guns to be installed is not particularly limited.

The pressure in the vacuum chamber during the deposition is 4 × 10 ⁻⁴ Pa
The exhaust system was designed to ensure the following at all times. Specifically, the structure was such that an oil diffusion pump of 50,000 L / sec was directly connected to the bottom of the vacuum chamber. In addition, the thickness of the mixed film layer after the vapor deposition was continuously measured by the thickness monitor 7 which was arranged almost directly above the measurement roll and at the center in the width direction of the polymer film 18.

Next, the thickness monitor 7 will be described in detail. First, the rhodium X-ray tube 7a is supplied with 40 kV, 50 mA.
Of the film 1 running on the measuring roll 5
8 was irradiated with primary X-rays perpendicularly. In this case, film 1
The X-rays applied to the deposited film on 8 are collimated 3
It is a light beam of 0 mmφ. A part of the characteristic (fluorescent) X-rays excited by the X-rays is substantially equidistant from the measurement position of the mixed film, and is located at an incident angle of approximately 30 ° with respect to the measurement roll surface 5. To the vessel 7b. The semiconductor detector 7b outputs a weak current when receiving the characteristic energy intensity of the elemental components of Si and Al, is converted into a voltage value (0 to 5V), and is converted into a voltage by an A / D converter (not shown). It is converted into a bit digital signal and output. In this embodiment, the semiconductor detector is a Si (Li) semiconductor detector.
An e (Li) semiconductor detector, a high-purity Ge semiconductor detector, or a high-purity Si semiconductor detector may be used, and the composition of the semiconductor is not particularly limited. However, when measuring the thickness of an element such as Si and Al whose energy distributions are balanced, it is preferable to use a Si (Li) semiconductor detector having high energy resolution.

As another method for detecting characteristic X-rays, there is a method using a proportional counter or the like.
The problem is that a crystal spectroscopy plate is required to narrow the line wavelength to a wavelength that depends on the target element, and the spectroscopy crystal plate and the proportional coefficient tube are required for the number of elements to be extracted, resulting in a large-scale device. is there.

The digital signal input to the pulse height analyzer 13 is converted into an energy spectrum in which the horizontal axis represents energy and the vertical axis represents a count value (intensity). From the spectrum data, the intensity of 1.84 keV, which is the energy of Si, and A
An intensity of 1.56 keV, which is an energy of 1, was obtained and converted into each thickness by the thickness calculator 14. In addition, the conversion method is defined as a value obtained by multiplying the vapor deposition film thickness of a plurality of vapor deposition samples having known thicknesses by X
A calibration curve of the line intensity was created in advance, and a method of converting the data into thickness data based on the calibration curve was adopted.

The thickness monitor 7 is arranged in a bird-like shape so that it can be arranged almost directly above each vapor deposition material in the width direction of the film.
A total of eight units were arranged in a row. An example of the arrangement is shown in FIG. The interval in the width direction of each thickness monitor 7 is 100 mm
It is. Note that the intervals, the number of arrangements, the number, and the like of the staggered arrangement may be determined based on the width dimension of the deposited film and the required quality of the deposited thin film, and are not particularly limited.

The thickness data calculated and output by the thickness calculator 14 is sent to the control amount calculator 15. here,
Based on the thickness data, the input power of the electron gun and the stay time of the electron beam are calculated. These control data are used to determine the evaporation rate (corresponding to the evaporation thickness) in each crucible determined in the experiment.
It was calculated based on the relational expression between energy and input energy. FIG.
It is the result showing the relationship between the input energy in the crucible 9 and the film deposition thickness. In the figure, A1, A2, A3, and A4 indicate positions of Al ₂ O _{3 in} the crucible, and S1, S2, and S
3, S4 not indicate the respective positions of the SiO ₂ in the crucible, the by different components adjacent alternately are sequentially arranged so as to face in the width direction of the film. As can be seen from FIG. 4, the target thickness and composition ratio can be controlled by adding or subtracting the energy amount corresponding to the deviation between the current thickness and the target value to or from the current value. However, since the energy supplied to these materials is the electron beam 19 emitted from the same electron gun 4, the energy supplied to each material is actually changed by changing the staying time of the electron beam for each crucible. Energy can be distributed. These relational expressions are shown below.

[0029] _{ta n = [Pa n / (} ΣPa + ΣPs)]
× t0 here, ta _n: electron beam scanning time Pa _n of aluminum oxide block n: amount of energy put into aluminum oxide block n ΣPa: total amount of energy put into the aluminum oxide a total of four blocks ShigumaPs: four Total energy amount to be input to silicon oxide of the block t0: Time constant depending on hardware (ms: millisecond) The distribution of gas evaporating from each evaporation block indicates the evaporation characteristics of each evaporation material in the crucible in FIG. As shown at 31 (evaporation component from the silicon oxide block) and 32 (evaporation component from the aluminum oxide block), the distribution is such that the intensity is highest immediately above, and the intensity decreases as it spreads laterally. The distribution intensity and shape mainly depend on the intensity of the electron beam, the angle at which the electron beam is incident, the distance between the electron gun and the crucible, and the evaporation area. Therefore, in order to form a film having the same composition ratio in the width direction and the running direction of the film forming the thin film and having a uniform target total thickness, the arrangement of the vapor deposition material is most important. The arrangement of the materials in this example is
As shown in FIGS. 2 and 3, the distance between the electron gun and the surface of the crucible closest to the electron gun was 1000 mm. In the figures, A and S indicate that Al ₂ O ₃ and SiO ₂ are stored, respectively.

The vapor deposition material is thin thin plate 20 shown in FIG.
The material was divided and arranged, and the polymer film 18 was deposited under the conditions described above. The running speed of the film is 300
m / min and a total of 40,000 m was deposited. The crucible is
It was moved at a speed of 2 mm / min toward the electron gun (the driving device is not shown). In order to confirm the effect of the automatic control, a comparison was made between the case where the automatic control was performed and the case where the control system was disconnected with the monitor device operating only. The control cycle of the automatic control was 30 seconds. Table 1 shows the results.
It can be seen that when the automatic control is not performed, the total thickness variation and the composition ratio variation are large, but when the automatic control is performed, a very stable film is formed.

(Example 2) A total of four thickness monitor devices 7 were arranged at regular intervals in a line in the film width direction. An arrangement example is shown in FIG. The interval in the width direction of each monitor device 7 is 2
00 mm. In this embodiment, it is not possible to measure the entire thickness of the deposited film just above each of the deposited materials as in the first embodiment. In order to solve this problem, a method of controlling each crucible by predicting the thickness between them by linear approximation based on measurement data was implemented. In the present embodiment, the approximation predicting means is performed by a linear expression. However, when there are many measurement points, approximation by a polynomial may be used, and there is no particular limitation. Other implementation conditions are:
This is the same as the first embodiment.

A comparison was made between the case where the automatic control was performed to confirm the effect of the automatic control and the case where the control system was cut off with the thickness monitor only operating. The control cycle of the automatic control was 30 seconds. Table 1 shows the results. It can be seen that when the automatic control is not performed, the total thickness variation and the composition ratio variation are large, but when the automatic control is performed, a very stable film is formed.

[0033]

[Table 1] [Other Embodiments] (1) In the above-described embodiment, an example in which a so-called one-chamber system is used as a vacuum chamber has been described. However, a chamber in which a material to be deposited such as a film travels is different from a chamber in which a deposition material is heated. The present invention is also applicable to a so-called two-chamber type apparatus in which vacuum deposition is performed under reduced pressure.

(2) In the above embodiment, the example in which the unwinding roll and the take-up roll of the material to be vapor-deposited are arranged in the vacuum chamber is shown. However, the present invention can also be applied to a continuous apparatus in which vapor deposition is performed in a high vacuum chamber.

(3) In the above embodiment, a polymer film is described as an example of the film-shaped material to be deposited, but the material to be deposited may be paper, cloth, or the like. In addition, as the vapor deposition material, various elements and compounds can be used in addition to the above-described aluminum oxide and silicon oxide. Further, a mixed film composed of two or more elements or components using two or more vapor deposition materials can be used. It may be formed.

(4) In the above embodiment, the heating means is an electron gun. However, the invention can be applied to a vapor deposition apparatus for heating a crucible by an induction heating coil.

[0037]

As described above, according to the present invention, a mixed film having a composition ratio of a mixed film of different elements and a target thickness is continuously formed on a running film surface for a long time in a film width direction and a running direction. Thus, it was possible to provide a vacuum vapor deposition apparatus capable of forming a film uniformly and stably.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a vacuum evaporation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a crucible used in a vacuum evaporation apparatus according to an embodiment of the present invention and an arrangement thereof.

FIG. 3 is a diagram illustrating the structure of the crucible of FIG.

FIG. 4 is a graph for explaining a relationship between a crucible input energy amount and a film deposition rate.

FIG. 5 is a graph illustrating the vapor deposition characteristics of each vapor deposition material block.

FIG. 6 is a diagram illustrating a method of arranging monitor devices.

[Explanation of symbols]

 Reference Signs List 4 heating means 6 vacuum tank 7 thickness monitor 7a X-ray irradiation means 7b semiconductor detector 9 holding means 15, 16 control means 18 film

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tsukasa Oshima 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyobo Research Co., Ltd. (72) Inventor Kiyoji Iseki 2-1-1 Katata, Otsu-shi, Shiga Prefecture F-term in Toyobo Co., Ltd. Research Laboratory (reference) 2F067 AA27 BB12 CC08 HH04 KK01 LL02 LL15 LL19 NN03 QQ01 2G001 AA01 BA04 CA01 EA03 GA01 KA01 KA09 LA20 MA05 NA18 4K029 AA11 AA25 CA01 DB21 EA01 EA09

Claims (6)

[Claims] 1. A vacuum deposition apparatus for forming a mixed film made of different elements on a film running in a vacuum chamber, a holding means capable of holding different types of deposition materials, and a heating device for heating and depositing the deposition materials. Means, X-ray irradiating means for irradiating the mixed film on the film formed by the heating means with X-rays, and a semiconductor detector for measuring the intensity of characteristic X-rays excited by the X-ray irradiating means; And a measuring means for outputting thickness data for each component of the mixed film. 2. The vacuum deposition apparatus according to claim 1, wherein the X-rays radiated by the X-ray radiating means are radiated substantially perpendicularly to the mixed film. 3. The vacuum vapor deposition apparatus according to claim 1, wherein the thickness monitoring devices including at least the X-ray irradiating means and the detector are arranged in a zigzag manner at substantially equal intervals in the film width direction. 4. The vacuum evaporation apparatus according to claim 1, wherein a thickness monitor comprising at least the X-ray irradiating means and the detector is arranged in a line in the film width direction at substantially equal intervals. 5. The vacuum deposition apparatus according to claim 1, further comprising control means for automatically controlling said heating means based on the thickness data output by said measurement means. 6. The vacuum evaporation apparatus according to claim 5, wherein said control means includes an arithmetic means for approximately predicting thickness data of a deposited film between said thickness monitoring apparatuses based on thickness data measured by a plurality of thickness monitoring apparatuses. Signage device.