JPH10230193A - High-frequency vibration spray nozzle for thin-film manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a nozzle port from clogging or a thin-film thickness from being spotted by providing a needle valve body conducting high-frequency vibration in the axial direction of the nozzle port at the vicinity of the inside of the nozzle port being provided with a minute opening spraying fluid for thin-film forming in minute droplets introduced into the inside of the nozzle via a liquid-communicating conduit into an inside of a vacuum device. SOLUTION: A position of a needle valve body 50 is coarsely controlled by manually rotating a micrometer 62 of a coarse control mechanism and then the needle valve body 50 is finely controlled to a specified position to a nozzle port 46 by applying a direct current bias voltage of a fine-control mechanism to a vibrating body 56 to elongate the vibrating body 56. High-frequency voltage is superimposed on the d.c. bias voltage and under the condition wherein the needle valve body 50 is finely vibrated up and down coaxially to the nozzle port 46 by the frequency, fluid A for thin-film forming from a storage tank is allowed to be turbulent flow at a pressure not less than an atmospheric pressure via a fluid passage 78 and a gap passage between a shaft 44 and a rod 52 and ejected from the nozzle port 46 in fine particles. As a result, clogging of the nozzle port is eliminated and particle sizes in ejected fluid are considerably reduced by allowing possibly entering dust particles to be discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an apparatus for manufacturing an organic engineering thin film and the like in a vacuum.
More specifically, the present invention relates to a spray nozzle for a thin film manufacturing apparatus capable of forming a thin film having a uniform thickness on a substrate with high efficiency without causing troubles such as clogging.

[0002]

2. Description of the Related Art Optical functional thin films related to optoelectronics technology and optical functional thin films related to electronic technology are formed.
Various technologies have been developed for some time. Among them, an inorganic substance or an organic substance is dissolved or dispersed in a solvent or a dispersion medium, and these are sprayed from a spray nozzle into a high vacuum vessel to be deposited on a substrate, and then the deposited layer is subjected to a heat treatment. The method of forming a thin film is an excellent method as a method for producing a high-performance composite optical thin film, and development for practical use is underway.

FIGS. 3 and 4 show an example of this type of spray nozzle conventionally used. The spray nozzle is connected to the vacuum vessel 2 via an O-ring 4 with bolts 6.
And is detachably fixed. The spray nozzle is configured by inserting a bonnet 10 into a recess forming a valve chamber of the valve body 8 and fixing the bonnet 10 with a bonnet nut 12. That is, a diaphragm 16 whose periphery is fixed by a holding adapter 14 is disposed in the concave portion, and a disk 18 connects the diaphragm 16 to the valve seat 8.
By pressing to the b side, the nozzle hole 8a is closed. The upper surface of the disk 18 is in contact with the lower end of the stem 22 which moves up and down by the rotation of the handle 20.
The stem 22 is urged upward by an elastic body 24.

[0004] The inner surface of the valve body 8 has a fluid outlet 8a.
The fluid supply pipe 26 is fixed on the upper surface side of the taper surface 8c. The fluid A for forming a thin film flows from the fluid supply pipe 26 into the fluid introduction passage 28 in the valve body 8, and when the nozzle hole 8 a is in a closed state, the fluid A enters the gap G formed between the diaphragm 16 and the upper surface of the valve body 8. It has accumulated.

FIG. 4 is a sectional view of a main part when the nozzle hole 8a is in an open state. When the handle 20 is rotated to raise the stem 22, the disk 18 is raised by the elastic force of the elastic body 24, the diaphragm 16 is separated from the valve seat 8b by its own elasticity, and the nozzle hole 8a is opened. At this time, the fluid A is ejected as minute droplets from the nozzle hole 8a into the vacuum vessel 2 through the fluid supply pipe 26, the fluid introduction path 28, and the gap G as indicated by arrows. The microdroplets adhere to a substrate (not shown) arranged in a vacuum vessel,
When the substrate is heated, the solvent or dispersion medium in the fluid evaporates and is absorbed by a nearby cold trap (not shown), and a thin film of an inorganic or organic substance as a solute is formed on the substrate.

[0006]

However, the conventional spray nozzles shown in FIGS. 3 and 4 have the following disadvantages. First, the first problem is that the fine droplets to be sprayed have a relatively large particle size, and as a result, the thickness of the formed thin film tends to be uneven. That is, in the spray nozzles shown in FIGS. 3 and 4, it is necessary to adjust the ejection flow rate of the fluid to about 100 μl / min from the viewpoint of the deposition rate of the fluid on the substrate. Has been selected. On the other hand, the fluid supply pressure is usually several tens kg / cm.
^{When the} fluid is sprayed from the nozzle hole 8a under this fluid pressure, the particle diameter of the fine droplet becomes relatively large, and as a result, unevenness occurs in the thickness of the thin film formed on the substrate. Become. Because the diaphragm 16 and the nozzle hole 8
a even if the passage gap between the nozzle hole 8 and the nozzle hole 8 is finely adjusted.
This is because “a” itself is fully opened with respect to the fluid A.

[0007] The second problem is that when dust generated inside the spray nozzle or dust generated inside the fluid supply device enters the fluid, the dust becomes a nucleus and clogs the nozzle hole 8a. That is to do. That is, since the length of the nozzle hole 8a is about 0.1 mm, once the dust particles bite into the inside of the nozzle hole 8a, the particles are unlikely to be spontaneously dislodged by the subsequent fluid flow. The subsequent fluid A is deposited as a nucleus, and the nozzle hole 8a is clogged.
It should be noted that if the length of the nozzle hole 8a is considerably shorter than 0.1 mm, the degree of biting of the dust particles becomes smaller. However, if the length is shortened, the flow of the fluid becomes unstable near the nozzle hole 8a due to the high fluid pressure, and the particle diameter of the fine droplets varies, making it impossible to form a uniform thin film. . Therefore, the length of the nozzle hole should be about 0.1
mm or less. Further, when the minute nozzle hole 8a is clogged, it takes a long time to repair the nozzle hole 8a, and the worst case of interrupting the thin film forming process occurs.

On the other hand, a needle valve system as shown in FIG. 5 has been developed in order to improve the above disadvantages. This needle valve system is disclosed in JP-A-6-306181 and JP-A-7-306181.
No. 252670 and Japanese Unexamined Patent Application Publication No. 7-252671, each of which discloses a needle-shaped needle valve 32.
Is inserted into the nozzle hole 30, and the needle valve 32 is moved up and down by the opening and closing mechanism 34 to adjust the ejection flow rate of the thin film forming fluid supplied from the liquid reservoir 36.

Since the needle valve 32 has a tapered shape, when the needle valve 32 is lowered, the gap between the needle valve 32 and the nozzle hole 30 becomes narrower, the particle diameter of the ejected fine droplets becomes smaller, and the uniformity of the thin film formed on the substrate is reduced. Certainly get better. However, similarly to the conventional example, the clogging phenomenon in the nozzle holes 30 due to dust particles could hardly be improved, and the emergence of a new technology that enables the thin film forming process to proceed smoothly has been expected.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks in the conventional spray nozzle for a thin film manufacturing apparatus. In a spray nozzle for a thin film manufacturing apparatus that forms a deposited layer of a fluid on a substrate by spraying a thin film forming fluid into a vacuum vessel, a fluid passage for introducing the thin film forming fluid into the nozzle, A nozzle hole having a minute opening for spraying a fluid flowing from the fluid passage into the vacuum device in the form of minute droplets, a needle valve body disposed near the inside of the nozzle hole, and a nozzle hole A high-frequency vibration type spray nozzle for a thin film manufacturing apparatus, comprising a vibrator that vibrates in the axial direction at a high frequency.

A second aspect of the present invention is characterized in that a position adjusting mechanism for adjusting the vertical position of the needle valve body coaxially with respect to the nozzle hole is added to the first aspect of the present invention.
A high frequency vibration type spray nozzle for a thin film manufacturing apparatus, wherein the position adjustment mechanism is divided into a coarse adjustment mechanism by mechanical means and a fine adjustment mechanism by electric means.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the needle valve element is moved from several kilohertz to several tens by the vibrator.
A high-frequency vibration is applied at a frequency of 00 kilohertz to control the particle size of the fine droplets of the sprayed fluid. The invention of claim 5 is the invention according to claim 1, wherein the fluid is supplied to the nozzle hole. This is a high-frequency vibration type spray nozzle for a thin film manufacturing apparatus in which a dispersion of a fluid is provided in a passage portion to be introduced, and the flow of the flowing fluid is made turbulent to further reduce the particle diameter of fine droplets.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a high frequency vibration type spray nozzle for a thin film manufacturing apparatus according to the present invention, and FIG. 2 is an enlarged sectional view of a main part of the spray nozzle.

In FIG. 1 and FIG. 2, a shaft insertion hole 40 is formed in a vacuum container 38 having an internal vacuum degree of about 1 × 10 ⁻⁴ Pa, and a nozzle 42 is screwed into the shaft insertion hole 40. The fitted shaft 44 is inserted. A nozzle hole 46 is formed at the center of the lower end of the shaft 44. The diameter φ and length L of the nozzle hole 46 are set to φ = 20 μm and L = 0.1 mm as shown in FIG. I have. Further, the inside of the nozzle hole 46 is formed in an inverted conical tapered surface 48, and an inverted conical needle valve body 50 is arranged coaxially with the tapered surface 48.

The inclination angle β of the distal end portion 50a of the needle valve body 50 is set to 30 degrees, and by adjusting the vertical position of the needle valve body 50,
distance L ₀ between the inner end surface of the b and the nozzle hole 46 is freely adjusted, the interval L ₀ when the fluid spray is set to a divisor μm~ number 10 [mu] m. Further, the needle valve body 50 is
The rod 52 is further fixed to an elastic body seat 54.
Is screwed on.

The connecting portion 79 between the needle valve body 50 and the rod 52 is formed in an octagonal column shape.
To form a fluid dispersion for making the flow turbulent.
That is, when the flow of the fluid A at the time of reaching the nozzle hole 46 is laminar, the droplets may be ejected with laminar flow without miniaturization. For this reason, in the present embodiment, the fluid dispersion is provided in the passage portion of the fluid, whereby the flow of the fluid reaching the nozzle hole 46 is made turbulent.

In FIG. 1 and FIG. 2, the octagonal column-shaped connecting portion 79 is formed as a fluid dispersion so that a gap passage between the shaft 44 and the rod 52 is formed to have a uniform cross-sectional width. Of the fluid A in the ring-shaped passage 81 by changing from a ring-shaped passage 80 of FIG.
Is made to be turbulent. Also, in FIGS. 1 and 2, the octagonal connecting portion 79 is a fluid dispersion, but any fluid dispersion may be used. For example, a spiral groove may be formed on the outer peripheral surface of the connecting portion 79. Alternatively, a dispersion member having an appropriate shape for making the flow of the fluid A turbulent may be provided in the space 82 above the nozzle hole 46.

The elastic body receiving seat 54 is integrally connected to a vibrating body fixing base 58 via a vibrating body 56, and the vibrating body fixing base 58 is connected to a micrometer 62 via a shaft 60. Further, since the elastic body receiving seat 54 is constantly urged upward by the elastic body 64, the vibrating body 56 and the vibrating body fixing base 58 are pressed against the lower end of the shaft 60.

By rotating the micrometer 62, the shaft 60
Is lowered, the elastic body receiving seat 54 descends while resisting the elastic force of the elastic body 64, and the needle valve body tip 50 b approaches the nozzle hole 46. When the micrometer 62 is reversed, the needle valve body tip 50b moves away from the nozzle hole 46.

The shaft 44 has O-rings 66, 66.
Are fixed to the lower surface of the valve body 68 by bolts 70. Also, the valve body 68 has an O-ring 7
It is air-tightly fixed to the upper surface of the vacuum container 38 via the bolts 74 via 2 and 72. Further, the micrometer 62 is integrally fixed to the upper surface of the valve body 68 by bolts 76,76.

The fluid A for forming a thin film flows from a storage tank (not shown) through a fluid passage 78 into an intermediate portion of the rod 52, and from the periphery of the rod 52 via a needle valve 50 through a nozzle hole 46 to a vacuum vessel 38. It is ejected toward a substrate (not shown) inside.

In this embodiment, a piezo element is used as the vibrator 56. When a high-frequency voltage of several kilohertz to several hundred kilohertz is applied, the piezo element repeatedly expands and contracts in synchronization with this frequency. Using the mechanical vibration of the piezo element, the needle valve body 50 is slightly vibrated in the vertical direction. The high-frequency vibration of the needle valve body 50 by the vibrating body 56 is an important element of the present invention. As another example of the vibrating body 56, a method in which a high-frequency current is supplied to a coil to finely vibrate a permanent magnet vertically, A known micro-vibration technique such as a pickup method for generating vibration and a method using ultrasonic vibration can be applied.

Next, the operation of the high frequency vibration type spray nozzle according to the present invention will be described. First, the needle valve element 50 is set at an appropriate position with respect to the nozzle hole 46 by operating the position adjusting mechanism. That is, first, the micrometer 62 which is a mechanical means as a coarse adjustment mechanism is manually rotated,
The position of the needle valve body 50 is roughly adjusted. Next, a DC bias voltage, which is an electrical means, is applied to the vibrating body 5 as a fine adjustment mechanism.
6, the vibrating body 56 is extended, and the needle valve body 50
Is finely adjusted to a desired position with respect to the nozzle hole 46.

At this time, it is desirable that the interval L ₀ is set to several μm to several tens μm. The smaller the _value of L ₀ , the smaller the gap between the needle valve tip 50 b and the inner peripheral edge of the nozzle hole 46, and the smaller the particle diameter of the fine droplet formed when the fluid is ejected from the nozzle hole 46. In addition, the smaller the particle size is, the more uniform the thickness of the thin film formed on the substrate becomes, so that a thin film having a uniform thickness can be formed. The adjustment limit of L ₀ by mechanical means such as a micrometer and electric means such as a DC bias voltage is about several μm, and L ₀ may be 0.1 to 0.1 μm depending on conditions.
It can be as large as 0.2 mm, and these will vary depending on the conditions for forming the thin film.

A high frequency voltage of several kilohertz to several hundred kilohertz is superimposed on the DC bias voltage, and the needle valve body 50 is vibrated up and down coaxially with respect to the nozzle hole 46 at the frequency. Then, under this condition, the thin film forming fluid A is ejected from the nozzle hole 46 through the fluid passage 78 at a pressure higher than the atmospheric pressure from a storage tank (not shown). That is, the thin-film forming fluid A pressed into the gap passage 80 between the shaft 44 and the rod 52 through the fluid passage 78 is completely turbulent while passing through the gap passage 81 provided with the fluid dispersion 79. Then, by flowing toward the nozzle hole 46, the particles are ejected as fine particles.

The first reason for finely vibrating the needle valve body 50 is to further reduce the particle diameter of the fine liquid droplets ejected from the nozzle hole 46. Needle valve body 50
When the tip 50b vibrates in the fluid, the tip 50b triggers the formation of fine droplets, and the particle size decreases as the frequency increases. If the frequency is lower than the lower limit of several kilohertz, the particle size of the droplet hardly changes. If the frequency is higher than the upper limit of several hundred kilohertz, it becomes difficult to further reduce the particle size.

The second reason is that the dust particles contained in the particles mesh with the wall surface near or inside the nozzle 46, and the thin film material in the particles precipitates with the particles as nuclei to cause nucleus growth. This is because, even if it occurs, the micro-vibration pressure wave by the needle valve body 50 acts to separate the nucleus from the wall surface. That is, the diameter of the nozzle hole 46 is about 20 μm.
Fluid interruption by nucleus growth, in other words, clogging phenomenon, was the biggest weak point of this type of spray nozzle. The present invention has succeeded in completely overcoming the problem of clogging due to fine vibration of the needle valve element. Further, even when dust particles are not mixed, a clogging phenomenon is easily induced when the viscosity of the fluid is high. However, the clogging phenomenon can be suppressed even for such a high viscosity fluid in the present invention.

As described above, the pressure applied to the fluid can be arbitrarily set, but is usually about 1 to 100 kg / cm ² . Further, since the inside of the vacuum vessel 38 is maintained at a high vacuum, the fluid A can be sprayed on the substrate even at a pressure lower than the atmospheric pressure (1 kg / cm ² ). The fluid pressure and the spray flow rate are directly related, and the fluid pressure can be freely adjusted according to the design in the context of the spray time, the spray pattern, and the desired film thickness of the thin film.

The fluid for forming a thin film used in the present invention is, for example, a solution or dispersion obtained by dissolving or dispersing an organic optical material in an organic solvent. However, since the organic solvent is adsorbed to the nearby cold trap during the spray flight or on the heated substrate, a thin film of, for example, only the organic optical material is formed on the substrate. The high frequency vibration type spray nozzle of the present invention described above can be applied to any thin film forming fluid as described above.

In the present invention, the needle valve element 50 can be set at a desired position with respect to the nozzle hole 46 by the position adjusting mechanism including the coarse adjustment mechanism and the fine adjustment mechanism. Can be arbitrarily adjusted, and the flow rate of the fluid A can be easily controlled. Also, by adjusting the opening, the internal pressure of the fluid can be varied, and simultaneously, by adjusting the external pressure applied to the fluid, the spray pattern of the fluid from the nozzle hole can be changed, and a desired thin film can be formed. Will be possible. Further, although a micrometer is illustrated as a coarse adjustment mechanism, a known axis moving mechanism can be applied. In addition, although the elongation effect of the piezo element by the DC bias voltage has been disclosed as the fine adjustment mechanism, other known electric mechanisms can be used.

The present invention is not limited to the above-described embodiment, but includes various modifications and design changes within the technical scope thereof without departing from the technical idea of the present invention. is there.

[0032]

As described above, according to the present invention, the needle valve body is vertically vibrated with respect to the nozzle hole by the vibrating body, so that even if dust particles are mixed in the fluid, these particles are forcibly discharged. In addition, even if the particles are engaged in the nozzle hole, the particles can be separated by the high frequency vibration pressure wave of the fluid. as a result,
The clogging phenomenon of the nozzle hole is almost completely overcome.

Further, even if the viscosity of the fluid becomes high, forced ejection of the fluid becomes possible by forced micro-vibration, so that clogging is suppressed.

Further, since the needle valve element can be set at a desired position with respect to the nozzle hole by the position adjusting mechanism, the opening degree of the nozzle hole can be adjusted, and the flow rate of the fluid can be easily adjusted. A body is provided in the fluid passage to make the flow of the fluid turbulent and then to the nozzle hole. As a result, the particle size of the fine droplets of the ejected fluid can be significantly reduced, and the spray pattern can be controlled by changing the internal pressure of the fluid. The present invention has excellent practical effects as described above.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a high frequency vibration type spray nozzle according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a longitudinal sectional view of a conventional spray nozzle.

FIG. 4 is an enlarged sectional view of a main part when the valve of FIG. 3 is opened.

FIG. 5 is a schematic configuration diagram of another conventional spray nozzle.

[Explanation of symbols]

A is a fluid for forming a thin film, β is an inclination angle of a tip portion of a needle valve, 38 is a vacuum container, 40 is a shaft insertion hole, 42 is a nozzle portion, 44 is a shaft, 46 is a nozzle hole, and 48 is an inverted conical tapered surface. , 50 is a needle valve body, 52 is a rod, 5
4 is an elastic body seat, 56 is a vibrating body, 58 is a vibrating body fixing table,
60 is an axis, 62 is a micrometer, 64 is an elastic body, 66
Is an O-ring, 68 is a valve body, 70 is a bolt, 72
Is an O-ring, 74 is a bolt, 76 is a bolt, 78 is a fluid passage, 79 is a fluid dispersion, and 80 and 81 are gap passages.

Claims (5)

[Claims] 1. A spray nozzle for a thin film manufacturing apparatus fixed to a wall surface of a vacuum container and spraying a thin film forming fluid into the vacuum container to form a deposited layer of the fluid on a substrate,
A fluid passage for introducing a fluid for forming a thin film into a nozzle, a nozzle hole having a minute opening for spraying a fluid flowing from the fluid passage into a vacuum device in the form of minute droplets, and disposed near the inside of the nozzle hole A high frequency vibration type spray nozzle for a thin film manufacturing apparatus, comprising: a needle valve element thus obtained; and a vibrator for vibrating the needle valve element in a high frequency direction with respect to the nozzle hole. 2. The high frequency vibration type spray nozzle for a thin film manufacturing apparatus according to claim 1, further comprising a position adjusting mechanism for adjusting the vertical position of the needle valve body coaxially with respect to the nozzle hole. 3. The high frequency vibration type spray nozzle for a thin film manufacturing apparatus according to claim 2, wherein said position adjusting mechanism comprises a coarse adjusting mechanism by mechanical means and a fine adjusting mechanism by electric means. 4. The vibrating body is from several kilohertz to several hundreds of kilohertz.
High frequency vibration of the needle valve at a frequency of kilohertz,
2. The high frequency vibration type spray nozzle for a thin film manufacturing apparatus according to claim 1, wherein the particle size of the fine droplet of the liquid to be sprayed is controlled. 5. A dispersion of a fluid is provided in a passage portion for introducing a liquid for forming a thin film into a nozzle hole, and a flow of the flowing liquid for forming a thin film is made turbulent to reduce a particle diameter of a microdroplet generated. A high-frequency vibration type spray nozzle for a thin film production apparatus according to claim 1.