JPS6147223B2 - - Google Patents

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 the improvement of

(b) Technology background With the rapid development of the information industry, various display devices are being developed.
Demand for panels has increased significantly. In the manufacturing process, a step of forming a vapor-deposited film of oxides such as MgO, Al ₂ O ₃ and Vycor glass frequently appears.

In order to form this vapor-deposited film on a 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 is used in which the evaporation sample is evaporated onto the rotating evaporator. 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 to a vacuum via the base 2, and a rotatable rotating frame 3 provided within the vacuum chamber 1 has a
A plurality of glass substrates 4 are held regularly, and one set of glass substrates 4 is moved to a predetermined deposition position or continuously rotated for each deposition process by external mechanical drive. . A vapor deposition sample (MgO, etc.) is placed in vapor deposition sample containers 5 (two in this case), and is vapor deposited onto a substrate 4 that has been preheated by a 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 vapor deposited films of oxides such as MgO and Al ₂ O ₃ . 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 piezoelectric 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 natural oscillation frequency decreases. When the mass of the deposit is M and the constant determined by the mechanical structure of the crystal oscillator is K, the following relationship exists between the mass and the natural oscillation frequency of the crystal oscillator.

=K/M (1) Therefore, by measuring the natural oscillation frequency of the crystal plate, the mass of the vapor deposited film deposited on the crystal plate, and hence the film thickness, can be calculated from equation (1).

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, causing part of the portion in close contact with the crystal plate to peel off. As a result, the natural oscillation frequency 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 deposited film is thick or the deposited film formation operation is repeated many times, the 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, a disk with slits is used to deposit the sample on the crystal plate of the film thickness sensor 7 in a uniform distribution.
Rotate it in front of the film thickness sensor 7. The mass of the vapor deposition sample deposited on the crystal plate of the film thickness sensor 7 is equal to that of the substrate 1.
The mass is reduced by a certain ratio, that is, the shielding rate, and the life of the film thickness sensor 7 can be extended accordingly.

By the way, in the case of FIG. 1, the attenuator 8 has a large rotating slit plate, and its rotating mechanism includes a huge gear part 9, so that the evaporation sample container 5 and the substrate 4 are arranged so as not to interfere with evaporation. It is provided diagonally above the vacuum chamber 1, avoiding the space between the two.

Next, we will discuss the direction of evaporation of oxides due to electron beam bombardment. FIG. 2A is a conceptual diagram showing a normal evaporation state, and the directional distribution of the amount of evaporation of the evaporation sample 11 bombarded by the electron beam 10 roughly follows the cosine law, as shown by the arrows. However, in the case of substances that have high viscosity and surface tension during evaporation, such as the oxides treated here, or substances that sublimate, deep holes may be formed partially on the surface of the evaporation sample in the evaporation sample container 5. Therefore, the directional distribution of the amount of evaporation of the sample deposited by the electron beam 10 is biased to one side as shown in figures b and c. This is difficult to avoid even if the electron beam 10 is swept and the impact point on the surface of the evaporation sample is adjusted in various ways. 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 indicated 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.

(e) Structure of the Invention The object of the invention described above is to provide a film thickness sensor composed of a crystal oscillator above a vapor deposition sample container, and to provide a slit portion that reciprocates in front of the film thickness sensor. A vapor deposition apparatus 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 vapor deposition sample container and the surface of the object to be vapor deposited. This is easily achieved by using

(f) Embodiments of the Invention As a result of various experiments, it has been found that the evaporation direction distribution in the direction directly above the evaporation source is substantially constant regardless of changes in the shape of the evaporation sample 11. Taking advantage of this fact, attention is paid to the fact that the film thickness sensor 7 may be provided directly above the vapor deposition sample container 5. In this case, although the film thickness sensor 7 is small, the attenuator 8 has a large mechanism, so there is a concern that the thickness of the deposited film on the substrate 4 may be unevenly distributed due to its shielding effect. 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, the film thickness sensor 7
Both are arranged directly above the vapor deposition sample container 5, respectively. The film thickness sensor 7 itself also prevents a part of the vapor deposition sample from evaporating from the vapor deposition sample container 5 and
Although there is a concern that the thickness of the vapor deposited film on the glass substrate 4 may become non-uniform, since the film thickness sensor 7 is small, its shielding effect is small, and in the conventional case, the film thickness of the portion directly above the evaporation source of the glass substrate 4 is The film was slightly thick, but the shape has been corrected, and the film thickness distribution has become flat, giving a rather good result.

The problem is the attenuator, but a slit portion 13 that can reciprocate in a predetermined direction has been introduced. As a result, 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, and the driving section 14 is moved into the evaporation space between the glass substrate 4 and the evaporation sample container 5. This makes it possible to arrange only the slit portion 13 in front of the film thickness sensor.

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. In addition, both parts have a thin ring-shaped connecting part 1 so as not to interfere with the vapor deposition.
Connected by 3A.

FIG. 4 is a perspective view showing an embodiment of the structure of the slit portion 13 and the drive portion 14. Drive section 14
The link mechanism 15 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 the 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 rough rectangular slit groups 18 in a direction perpendicular to the reciprocating motion. Although a fine mesh structure is conceivable for the slit portion 13, this type is unsuitable because it has the drawback of being easily clogged by the deposition of the deposition 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.

In addition, the structure of the slit portion 13 is a flat plate with reciprocating motion, but as shown in FIG. part 18
But that's fine.

Furthermore, in the above explanation, the present invention was applied to a vapor deposition process using electron beam bombardment in a vacuum, but it is also applicable to sputtering, ion beam, or thermal evaporation methods in which a deposition sample is heated and evaporated. It is possible.

(g) Effects of the invention As is clear from the above explanation, when a vapor deposition film is formed on the surface of an object by vaporizing a vapor deposition 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 glass substrate, 5 is a vapor deposition sample container, 6 is a heater, 7 is a film thickness sensor, 8 and 12 are attenuators, 9 is a gear unit, 10
11 is an electron beam, 11 is a vapor deposition sample, 13 is a slit portion, 14 is a driving portion, 15 is a link mechanism, 16 is a rotating shaft, 17 is a floating support portion, 18 is a group of slits,
F indicates an electron beam source, respectively.

Claims (1)

[Claims] 1. In a vapor deposition apparatus equipped with a film thickness sensor composed of a crystal oscillator, the film thickness sensor is disposed above the vapor deposition sample container directly facing the vapor deposition sample container, and the entire surface of the film thickness sensor an attenuator for the film thickness sensor, comprising a slit portion that makes reciprocating motion in the slit portion and a drive portion that drives the slit portion provided outside the evaporation space between the evaporation sample container and the surface of the object to be evaporated; A vapor deposition apparatus characterized by: