JPS5920467A - Vapor deposition device - Google Patents

Abstract

PURPOSE:To provide a vapor deposition device which enables the formation of a vapor-deposited film subjected to an exact measurement and control, by the constitution wherein a thick film sensor is disposed above a vessel for vapor deposition sample and an attenuator having a slit part in the driving part provided on the outside of a vapor deposition space part is moved forward and backward. CONSTITUTION:A thick film sensor 7 constituted of a crystal oscillator is disposed above a vessel 5 for a vapor deposition sample and the thickness of the thin film is measured and controlled therewith to form the film to a specified thickness and to stop the operation of vapor deposition in a vapor deposition device which evaporates an oxide or the like from the vessel 5 in a vacuum vessel 1 provided on a base plate 2 and forms the thin film on a glass substrate 4 supported and rotated by a rotary frame 3 and preheated with a heater 6. An attenuator 12 having a slit part 13 which is moved back and forth by a driving part 14 is provided on the front surface of the sensor 7 so that the long term use of the sensor 7 is made possible. The part 14 is disposed on the outside of the space part for the vapor deposition to avert the decrease in the efficiency of vapor deposition.

Description

Detailed Description of the Invention +a) Technical Field of the Invention The present invention relates to a vapor deposition apparatus, and more particularly to an attenuator for a vapor deposition film thickness sensor that continuously measures the thickness of a vapor deposited film while it is being formed in a vapor deposition tank. Regarding improvements.

Background of fbl Technology As various display devices are being developed with the rapid development of the information industry, the demand for EL display panels and PDP panels is increasing significantly. In the manufacturing process, for example, M
A process of forming a vapor deposited film of oxides such as gO+Al2O3+' to equal glass is frequently appearing.

In order to form this vapor-deposited film on a single substrate such as a glass plate in mass production, a plurality of the substrates are held in a rotating frame in an evacuated vapor deposition tank and moved one after another to a predetermined position, or the substrates are continuously moved to a predetermined position. A method has been adopted in which the evaporation sample is evaporated onto the evaporation sample. At this time, controlling the thickness of the deposited film is particularly important from the standpoint of maintaining the quality and reliability of the product.

(C) Prior Art and Problems An example of a mass-production method for forming the above-mentioned oxide on a substrate is conceptually shown in the sectional view of FIG.

The vacuum chamber 1 is evacuated via the base 2, and the vacuum chamber l
In the rotatable frame 3 provided inside.

A plurality of glass substrates 4 are held regularly at 111.

A set of glass substrates 4 are continuously rotated by a force A to move them to a predetermined deposition position for each vapor deposition process by an external mechanical drive. The vapor deposition sample (MgO, etc.) is placed in the vapor deposition sample container 5.
(in this case, 2 pieces).

It is deposited on the substrate 4 which has been preheated by the heater 6 .

The surface of the vapor-deposited sample is evaporated by the impact of an electron beam emitted from an electron beam gun (not shown), forming a vapor-deposited film on the glass substrate 4.

The thickness of the deposited film is constantly measured by two film thickness sensors 7 provided at the top of the vacuum chamber 1, and the system automatically stops the deposition when a predetermined film thickness is obtained. A rotary attenuator 8, which will be described later, is provided in front of the film thickness sensor 7.

A quartz plate is used as a film thickness sensor for a deposited film of an oxide such as MgO or AIz03. The operating principle will be described next.

As is well known, a crystal cut at a certain appropriate angle has a certain electric natural oscillation frequency f determined by its mechanical properties. Generally, crystals have a piezo effect, and there is an exchange of energy between mechanical energy and electrical energy. In particular, when a substance (mass) is added to the crystal plane, the characteristic oscillation frequency f decreases. The mass of the deposit is M
, let K be the constant determined by the mechanical structure of the crystal oscillator.

The following relationship exists between the natural oscillation frequency f of the crystal oscillator.

f = /M (11) Therefore, by measuring the natural oscillation frequency f of the crystal plate, the mass of the vapor deposited film deposited on the crystal plate, and therefore the film thickness, can be calculated from the fl1 formula.

However, when the thickness of the vapor deposited film on the crystal plate of the film thickness sensor 7 exceeds a certain thickness, stress is generated in the vapor deposited layer, and a part of the part in close contact with the crystal plate peels off. As a result, the natural oscillation frequency f of the crystal oscillator becomes unstable, and the film thickness sensor becomes useless and is considered to be at the end of its life.

Therefore, when the thickness of the evaporated film is large or when the process of forming the evaporated film is repeated many times, the above-mentioned attenuator is provided in front of the film thickness sensor in order to extend the life of the film thickness sensor. This is a kind of slit. In the case of FIG. 1, it is a circular plate with slits in order to deposit the vapor deposition sample in a uniform distribution on the crystal plate of the film thickness sensor 7.

Rotate it in front of the film thickness sensor 7. The mass number of the vapor deposition sample deposited on the quartz plate of the film thickness sensor 7 becomes smaller by a certain ratio than the mass on the substrate 1, that is, the shielding rate becomes smaller, and the life of the film thickness sensor 7 can be extended accordingly. I can do it.

By the way, in the case of FIG. 1, the attenuator 8 has a large rotating slit plate and also includes a gigantic gear part 9 with a side G of the rotating machine. It is provided diagonally above the vacuum chamber 1, avoiding the space between it and the substrate 4.

Next, we will discuss the direction of evaporation of oxides due to electron beam bombardment. Figure 2 (8) is a conceptual diagram showing a normal evaporation state, where the evaporation sample 1 is bombarded by the electron beam 10.
The directional distribution of the evaporation amount of 1 roughly follows the cosine law as shown by the arrow. However, in the case of substances that have high viscosity and surface tension during evaporation, such as oxides, which are sublimable, the surface of the evaporation sample in the evaporation sample container 5. It is easy to have deep holes in some areas,
Therefore, the directional distribution number of the amount of evaporation of the sample deposited by the electron beam 10 is (b).

As shown in the fC1 diagram, it is biased to one side. Now it's time to move the electron beam 10 across the surface of the evaporation sample.
Even if you adjust the firing point in various ways, it is difficult to avoid.

For the above reasons, as the surface of the vapor deposition sample 11 in the vapor deposition sample container 5 changes its shape due to the impact of the electron beam, the evaporation direction distribution of the vapor deposition sample changes. It is difficult to say that the film thickness of the vapor deposition sample on the quartz plate of the sensor 7 is necessarily representative of the film thickness on the substrate 4, and there is a problem that the reliability of the indicated value of the film thickness sensor 7 becomes low.

(d) Purpose of the Invention The present invention has been made in view of the above-mentioned points. The purpose is to reduce the discrepancy between the value and the thickness of the deposited film on the glass substrate 1 as much as possible to improve the reliability of the measured value.

tel Structure of the Invention An object of the above invention is to arrange a film thickness sensor composed of a crystal oscillator above a vapor deposition sample container, and to connect a slit portion that makes reciprocating motion to a vapor deposition sample in front of the film thickness sensor. A vapor deposition apparatus is used, characterized in that it has an attenuator for the film thickness sensor, which is constituted by a drive section that drives the slit section provided outside the vapor deposition space between the container and the surface of the object to be vapor deposited. This is easily achieved by

(fl Embodiment of the Invention As a result of various experiments, it was found that the evaporation direction distribution in the direction directly above the evaporation source has little relation to changes in the shape of the evaporation sample 11 and is approximately constant.Using this fact, We will focus on the fact that the film thickness sensor 7 can be installed directly above the vapor deposition sample container 5. In this case, the film thickness sensor 7 is small, but since the mechanism of the attenuator 8 is large, its shielding effect makes it difficult for the substrate 4 There is a concern about non-uniform distribution of the thickness of the deposited film.Embodiments of the present invention that eliminate these drawbacks will be described below with reference to the drawings.

FIG. 3 is a conceptual cross-sectional view showing the structure of a vapor deposition apparatus equipped with a new attenuator based on the present invention.

As shown in the figure, in the present invention, both film thickness sensors 7 are arranged directly above the vapor deposition sample container 5, respectively. Although there is a concern that the film thickness sensor 7 itself may obstruct a part of the vapor deposition sample evaporating from the vapor deposition sample container 5 and cause non-uniformity in the thickness of the vapor deposited film on the glass substrate 4, since the film thickness sensor 7 is small, The shielding effect is small, and in the conventional case, the glass substrate 4
The thickness of the film directly above the evaporation source was corrected, and the film thickness distribution became flat, yielding even better results.

The problem is the attenuator, but the structure is such that the slit portion 13 of the attenuator 12 and its driving section 14 are separated so as not to interfere with the deposition of the evaporation sample onto the glass substrate 4. It is provided outside the vapor deposition space between the sample container 5 and has a structure in which only the slit portion 13 is placed in front of the film thickness sensor 7.

As shown in the figure, the slit portion 13 consists of two plate-shaped portions having a predetermined shielding rate, each of which shields its respective film thickness sensor 7. Moreover, the image parts are connected by a thin ring-shaped connecting part 13^ so as not to interfere with the vapor deposition.

FIG. 4 is a perspective view showing an embodiment of the structure of the slit portion 13 and the drive portion 14. As shown in FIG. Link mechanism 1 of drive unit 14
5 is driven by a rotating shaft 16 that is driven and rotated from outside the vacuum chamber 1, and gives the slit portion 13 reciprocating motion in the direction shown by the arrow in the figure. One end of the slit portion 13 is connected to a link mechanism 15, and the other end is supported by a floating support portion 17 in a reciprocating manner.

The slit portion 13 has a plurality of roughly rectangular slit groups 18 in a direction perpendicular to the reciprocating motion. A fine mesoche structure can be considered in the slit portion 13.

This type is not suitable because it tends to cause clogging due to evaporation of the evaporation sample.

In the above description, two evaporation sources are provided, but of course there is no problem with one or three or more evaporation sources, and the type of material of the substrate on which the evaporation sample is to be evaporated does not matter.

Further, the structure of the slit portion 13 is also a flat plate shape that causes reciprocating motion, but as shown in FIG. It may also be part 18.

Furthermore, in the above explanation, the present invention was applied to a deposition process using electron beam bombardment in a vacuum, but the same applies to a sputtering method, an ion beam method, or a thermal evaporation method in which a deposition sample is heated and evaporated. It can be applied.

(gl) Effects of the Invention As is clear from the above explanation, a case where a deposited film is formed on the surface of an object by evaporating a deposited sample.

Use of the vapor deposition apparatus according to the present invention has the advantage that a highly reliable vapor deposition film that is accurately measured and controlled can be formed.

[Brief explanation of the drawing]

Fig. 1 shows the structure of a conventional vapor deposition apparatus for mass production, and Fig. 3 conceptually shows the structure of a vapor deposition apparatus equipped with an attenuator for a film thickness sensor with a new structure according to the present invention. Figure 2 is an explanatory diagram showing the evaporation direction distribution of the deposited sample due to the impact of the electron beam, Figure 4 is a perspective view showing the structure of the new attenuator according to the present invention, and Figure 5 is the attenuation shown in Figure 4. It is a perspective view showing a modification of the structure of the vessel. 1 is a vacuum chamber, 2 is a base, 3 is a rotating frame, 4 is a large board,
5 is a vapor deposition sample container, 6 is a heater, 7 is a film thickness sensor, 8.
12 is an attenuator, 9 is a gear part, 10 is an electron beam, 11 is a layered sample, 13 is a slit part, 14 is a sliding part, 15 is a link mechanism, 16 is a rotating shaft, 17 is a floating support part, 18 is a The slit group and F indicate the electron beam source, respectively.

Claims (1)

[Claims] In a vapor deposition apparatus equipped with a film thickness sensor composed of a crystal oscillator, the film thickness sensor is disposed above a vapor deposition sample container, and a slit portion that reciprocates in front of the film thickness sensor and a vapor deposition sample are arranged above the vapor deposition sample container. A vapor deposition apparatus characterized by having an attenuator for the film thickness sensor that is constituted by a drive section that drives the slit section provided outside the vapor deposition space between the container and the surface of the object to be vapor deposited.