KR100611667B1 - apparatus for detecting a thickness of a vapor deposition - Google Patents

Abstract

 The present invention relates to a thin film deposition measuring apparatus that extends the life of a crystal oscillator by adjusting the amount of deposited deposits, and is particularly located in front of the body and the first exposure window on which the first exposure window is exposed. And a barrier plate formed with a second exposure window, and when the blocking plate or the body rotates so that the first exposure window and the second exposure window overlap, the deposit is deposited on the crystal vibrator.

Thin Film Deposition, Evaporation Source, Crystal Oscillator, Blocker

Description

Apparatus for detecting a thickness of a vapor deposition

1 is a perspective view of an embodiment of a thin film deposition measuring apparatus according to the present invention.

2A, 2B, and 2C show various embodiments of the shape of the second exposure window formed in the blocking plate.

** Explanation of symbols in main part of drawing **

100: body,

110: crystal oscillator,

120: first exposure window,

150: blocking plate,

160: second exposure window.

The present invention relates to a thin film deposition measuring apparatus for measuring the rate (deposition rate) or the thickness of depositing a thin film on a substrate, and more particularly, the thin film deposition measurement which extends the life of the crystal oscillator by adjusting the amount of deposited deposits. Relates to a device.

BACKGROUND OF THE INVENTION Organic light emitting devices are rapidly developing on the background of advantages such as low voltage driving, low power consumption, high brightness, fast response, wide viewing angle, and thinness compared to liquid crystal display devices. .

In the organic light emitting device, electrons and holes injected through a cathode and an anode recombine to an organic layer to form excitons, and light of a specific wavelength is generated by energy from the formed excitons. Use the phenomenon.

The organic light emitting display device has a stacked structure of an anode, a multilayer organic thin film, and a cathode on a substrate. The organic thin film is largely divided into a polymer organic thin film and a low molecular organic thin film, and the polymer organic thin film forms a thin film using spin coating, dip coating, inkjet printing, and the like. Vacuum deposition using an evaporator at ^-7 torr vacuum.

A thin film deposition measuring apparatus is used to measure the thickness or deposition rate of a thin film deposited on a substrate in a vacuum deposition process. As a thin film deposition measuring apparatus, a device using a crystal oscillator is commonly used.

Apparatuses for measuring deposition rates using crystal oscillators are disclosed in US Pat. No. 3,383,842 or US Pat. No. 3,541,894. It coats the metal on both the front and back sides of the crystal oscillator and connects it to the appropriate oscillator circuit as anode and cathode, respectively. At this time, the equivalent admittance of the crystal vibrator is maximized at the natural frequency. If the natural frequency of the crystal oscillator changes, so does the frequency of the oscillator.

The crystal oscillator is placed in a vacuum chamber where vacuum deposition takes place and exposed to deposits (eg, low molecular weight organic materials) from the evaporation source. As deposits adsorb on the surface of the crystal oscillator, the mass of the crystal oscillator increases and its natural frequency decreases. By measuring the natural frequency variation, the rate at which the deposit is deposited or the thickness of the deposit is determined.

The biggest disadvantage of the thin film deposition measurement apparatus using the crystal oscillator is that the lifetime of the crystal oscillator is very limited. This is because deposits on the surface of the crystal oscillator weaken the resonance and eventually the crystal oscillator does not vibrate. Therefore, it is necessary to replace the crystal oscillator at regular intervals to measure accurate deposition rate. However, if the replacement cycle is too short, the process must be stopped every time, causing the process to be delayed. Also, if excess deposits are adsorbed onto the crystal oscillator before the replacement cycle, an error in deposition rate will occur. In order to solve the above problems, various methods for extending the life of the crystal oscillator have been proposed.

US Patent No. 4,817,430 proposes a method of monitoring the state of the crystal oscillator to inform the time of replacement. However, this can only know the replacement time, there is a problem that does not extend the life of the crystal oscillator itself.

US Patent No. 5,112,642 proposes a method for extending the life of the crystal oscillator by forming a buffer layer between the crystal oscillator and the positive electrode layer. However, this is only possible for limited deposits and there is a problem that the extended period is also limited.

US Patent No. 5,025,664 proposes a thin film deposition measuring apparatus which extends the overall life by mounting a plurality of crystal vibrators in one sensor and changing the crystal vibrators one by one. However, even with this document, there is a problem that does not extend the life of the crystal oscillator itself.

The technical problem to be achieved by the present invention is to provide a thin film deposition measuring apparatus that can be used for a longer time without affecting the sensitivity of the crystal oscillator to solve the above problems.

In order to solve the above technical problem, the present invention includes a body having a first exposure window to which a crystal oscillator is exposed and a blocking plate formed on a front surface of the first exposure window and having a second exposure window overlapping the first exposure window. A deposit is deposited on the crystal vibrator as the plate rotates to overlap the first and second exposure windows.

The area of the second exposure window is preferably larger than 0.5 times the area of the first exposure window.

Preferably, the rotation period of the blocking plate is greater than 0.1 times the sampling period of the crystal vibrator, and the rotation period of the blocking plate is preferably greater than at least 1 Hz.

On the other hand, the present invention includes a body formed with a first exposure window is exposed to the crystal oscillator and a blocking plate formed on the front of the first exposure window and the second exposure window overlapping the first exposure window, the body is rotated to the first A deposit is deposited on the crystal vibrator when the first and second exposure windows overlap.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present embodiment is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments make the disclosure of the present invention complete, and the scope of the invention to those skilled in the art to the fullest extent. It is provided to inform you. Shapes of elements in the drawings may be exaggerated parts to emphasize more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements.

1 is a perspective view of an embodiment of a thin film deposition measuring apparatus according to the present invention.

Referring to FIG. 1, the thin film deposition measuring apparatus according to the present exemplary embodiment includes a body 100 and a blocking plate 150.

 Inside the body 100, one crystal vibrator 110 or a plurality of crystal vibrators are mounted. An example of a body equipped with a plurality of crystal vibrators is disclosed in US Pat. No. 5,025,664. Although a plurality of crystal vibrators are mounted on the body 100, only one crystal vibrator 110 is exposed to the outside through the first exposure window 120. The deposit injected through the evaporation source (not shown) is deposited on the surface of the crystal oscillator 110 exposed through the first exposure window 120 so that the thin film deposition measuring apparatus measures the deposition rate.

In order to control the amount of deposits flowing into the first exposure window 120, the blocking plate 150 is disposed on the front surface of the present invention. In the blocking plate 150, a second exposure window 160 is formed to overlap the first exposure window 120 so that deposits may be introduced. The deposit is deposited on the crystal vibrator 110 only when the second exposure window 160 and the first exposure window 120 overlap.

In this embodiment, the blocking plate 150 is rotated so that the first exposure window 120 and the second exposure window 160 overlap each other at regular intervals. That is, if the second exposure window 160 is stopped, the amount of deposits flowing into the crystal vibrator 110 is not changed. However, if the second exposure window 160 is rotated so as to overlap the first exposure window 120 at a predetermined cycle, the blocking plate 150 serves as a kind of shutter so that the crystal vibrator 110 is exposed to the deposit at regular intervals. Result.

There is no restriction on the method of rotating the blocking plate 150. In this embodiment, the rotating shaft of the motor (not shown) is connected to the blocking plate 150 to rotate.

In order to minimize the amount of deposits introduced without affecting the sensitivity of the crystal vibrator 110, the rotation period of the blocking plate 150 and the shape of the second exposure window 160 are important.

In this embodiment, the rotation period of the blocking plate 150 is greater than 0.1 times the sampling frequency of the crystal vibrator 110. That is, the blocking plate 150 is rotated sufficiently smaller than the sampling period of the crystal vibrator 110.

The controller (not shown) connected to the crystal vibrator 110 calculates the deposition rate at a constant sampling period. For example, a device using a conventional crystal oscillator has a sampling period of 10 Hz (samples once every 0.1 seconds) and outputs an average of 10 times. That is, output once every second. In this embodiment, the rotation period of the blocking plate 150 is determined at 1 Hz, which is 0.1 times the sampling frequency of the conventional device, 10 Hz. That is, the blocking plate 150 rotates once a second.

In addition, if the sampling period of the crystal oscillator 110 is too small, the rotation period of the blocking plate 150 is too small, there is a problem in the control of the rotation of the blocking plate 150 due to the friction force. Therefore, in this embodiment, the minimum value of the rotation period of the blocking plate 150 is 1 Hz. That is, at least the blocking plate 150 is to rotate one second per second.

2A, 2B and 2C show various embodiments of the shape of the second exposure window formed in the blocking plate.

If the sizes of the second exposure windows 210a, 210b, and 210c are too small, the amount of deposited deposits may be too small to measure the deposition rate. In the present embodiment, the areas of the second exposure windows 210a, 210b, and 210c are 0.5 times larger than the areas of the first exposure windows 220a, 220b, and 220c.

One or more second exposure windows 210a, 210b, and 210c may be formed. At this time, the area of each second exposure window may be the same, but may be different.

That is, the second exposure window may have various forms to adjust the amount of deposits flowing into the crystal vibrator in consideration of the amount of deposits coming from the evaporation source and the rotation period of the blocking plate.

The operation of the thin film deposition measuring apparatus according to the present embodiment configured as described above will be described with reference to FIG. 1. When the deposit is injected from the evaporation source (not shown), the blocking plate 150 starts to rotate. As the blocking plate 150 rotates, the first exposure window 120 and the second exposure window 160 overlap each other at predetermined intervals, and the amount of deposits flowing into the crystal vibrator 110 is reduced than when the blocking plate 150 is not present. . Thus, the life of the crystal oscillator 110 is extended and the life of the device is increased by that. If you use multiple crystal oscillators alternately, the life of the device can be dramatically increased.

A second embodiment of the thin film deposition measuring apparatus according to the present invention will be described below.

The second embodiment according to the present invention has the same configuration as the first embodiment except that the blocking plate stops and the body rotates. In the first embodiment, the blocking plate is rotated while the body is stopped, but the same effect can be obtained even when the body is rotated while the blocking plate is stopped. Therefore, the same reference numerals are used to denote the first embodiment, and duplicate description thereof will be omitted.

As the body 100 rotates, the first exposure window 120 and the second exposure window 160 overlap each other at regular intervals. That is, if the first exposure window 120 is rotated so as to overlap the second exposure window 160 at a predetermined period, the blocking plate 150 serves as a kind of shutter to expose the crystal vibrator 110 to the deposit at a predetermined period. Result.

The rotation period of the body 100 is greater than 0.1 times the sampling period of the crystal oscillator 110. That is, the body 100 rotates smaller than the sampling period of the crystal oscillator 110. In addition, if the sampling period of the crystal oscillator 110 is too small, the rotation period of the body 100 is too small, there is a problem in the rotation control of the body 100 due to the friction force. Therefore, the minimum value of the rotation period of the body 100 is to be 1 Hz. That is, at least one body spins a second.

Except for the above matters, the description is the same as in the first embodiment, and thus the description thereof is omitted.

 As described above, according to the present invention, the life of the crystal vibrator is extended by installing a blocking plate on the front surface of the crystal vibrator and rotating the blocking plate or the body so that deposits are deposited on the crystal vibrator at regular intervals.

Therefore, the replacement timing of the thin film deposition measuring apparatus can be delayed, thereby improving productivity.

Claims (8)

A body having a first exposure window through which the crystal oscillator is exposed A blocking plate formed on a front surface of the first exposure window and having a second exposure window overlapping the first exposure window; And depositing the deposited material on the crystal vibrator when the blocking plate rotates so that the first exposure window and the second exposure window overlap each other. The method of claim 1, And the area of the second exposure window is greater than 0.5 times the area of the first exposure window. The method of claim 1, And the rotation period of the blocking plate is greater than 0.1 times the sampling period of the crystal oscillator. The method of claim 3, wherein And the rotation period of the blocking plate is greater than at least 1 Hz. A body having a first exposure window through which the crystal oscillator is exposed A blocking plate formed on a front surface of the first exposure window and having a second exposure window overlapping the first exposure window; And depositing the deposit on the crystal vibrator when the body rotates to overlap the first and second exposure windows. The method of claim 5, And the area of the second exposure window is greater than 0.5 times the area of the first exposure window. The method of claim 5, And the rotation period of the body is greater than 0.1 times the sampling period of the crystal oscillator. The method of claim 7, wherein And a rotation period of the body is greater than at least 1 Hz.

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