JPS61256623A - Thin film formation equipment - Google Patents

Abstract

PURPOSE:To almost eliminate the leakage of the vapor of an evaporation material from a fitted part and to improve the efficiency of the evaporation of the material to a substrate by making the construction of a crucible wherein the side wall of an upper lid is fitted with the inner wall of the crucible and the upper lid reaches near the bottom of the crucible. CONSTITUTION:This equipment has an upper lid 5a wherein the side wall of the lid is fitted with the inner wall of a crucible 5b and the upper lid 5a is inserted in the crucible 5b and reaches near the bottom of the crucible 5b. An evaporation material 4 is filled to approx. 80% of the volume of the crucible 5b. The operation is similar to that of a conventional equipment wherein the evaporation material 4 heated to a liquid state is evaporated from the liquid surface, the vapor is exhausted from the small hole 5c of the upper lid 5a and evaporated on a substrate 24 placed at the upper part of a vacuum tank 1 but in this equipment, the melted liquid of the evaporation material 4 is filled in the fitted part of the crucible 5b and the upper lid 5a and almost no melted liquid leaks from the fitted part. In this way, this equipment can extremely improve the efficiency of the evaporation of the material on the substrate.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention provides i4m! ! ! ! This invention relates to a thin film forming apparatus for vapor depositing.

[Conventional technology]

FIG. 2 is a sectional view showing a conventional thin film forming apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. 54-9592, and in the figure,
1 is a vacuum chamber, 2 is a vacuum exhaust port, 3 is a vacuum exhaust port valve,
4 is a vapor deposition material, 5 is a crucible in which the vapor deposition material 4 is placed, 5d
is the upper lid of the crucible 5, 5b is the crucible body, and 5c is a small hole in the upper lid 5d of the crucible. The reason why the crucible upper lid 5d and the crucible body 5b are separated here is to facilitate processing and to facilitate replenishment of the vapor deposition substance 4. 6 is a crucible support base; 7 is an electron bombardment filament that emits electrons to heat the crucible 5;
8 is a crucible heat shield plate that blocks heat radiation from the crucible 5 and the electronic bombardment filament 7; 9 is a crucible insulator that supports the crucible support 6; and 10 is a crucible heat shield plate insulator that supports the crucible heat shield plate. things, 11
12 is an ionizing filament that emits electrons for ionizing clusters made of vapor of the vapor deposition substance 4 ejected from the crucible 5; 12 is the ionizing filament 1;
13 is an ionization heat shield plate that blocks heat radiation from the ionization filament 11; 14 is an ionization heat shield plate insulator that supports the ionization heat shield plate 13; 15 is an ionization heat shield plate insulator that supports the ionization filament 11'; , 16 is an accelerating electrode, 17 is an accelerating electrode insulator that supports the accelerating electrode, 18 is a neutral cluster of the vapor deposited material 4 ejected from the crucible 5, 19 20 is a cluster beam containing the neutral cluster 18 and the ionized cluster 19; 21 is a shutter that blocks the cluster beam 20; 22 is a shutter that blocks the cluster beam 20; A shutter support rod 23 for supporting and rotating is a shutter support keyaki seal portion 2 through which the shutter support rod 2□2 passes through the vacuum chamber 1.
4 is a substrate, 25 is a substrate holder, and 26 is a substrate holder seal portion.

Next, the operation will be explained.

The air inside the vacuum chamber 1 is evacuated from the vacuum exhaust port 2 through the evacuated pulp 3 to make the inside of the vacuum chamber 1 a high vacuum region. Thermal electrons emitted from the electron bombarded filament 7 are transferred to the vapor deposition material 4.
The crucible 5 containing the crucible is bombarded with electrons to heat and evaporate the deposited material 4 in the crucible 5. Deposited substance 4 in the crucible 5
is heated to a temperature where the vapor pressure of the sample becomes several Torr. By doing so, the vapor of the vapor deposition substance 4 is ejected from the small hole 5c of the crucible upper lid 5d into the high vacuum region. At this time, the ejected steam is supercooled by adiabatic expansion due to the pressure difference between the crucible 5 and the vacuum chamber 1, and becomes a cluster beam 20.

The cluster beam 20 collides with the ionized electrons 15 extracted from the ionized filament 11 by the electron extraction grid 12, whereby the cluster is ionized and becomes an ionized cluster 19. Some clusters do not collide with ionized electrons 15 and are neutral clusters 18
collides with the substrate 24 at the speed of ejection from the crucible 5,
It is deposited on the substrate 24. At this time, ionization cluster 1
9 is accelerated by an electric field formed between the electron extraction grid 12, the ionization heat shield plate 13, and the accelerating electrode 16, with the former being positive and the latter being negative, and the neutral cluster 1 is
8 and is deposited on the substrate 24. The shutter 21 is an opening/closing device that controls the cluster beam 20 and is used to form WIIII of a required thickness on the substrate 24.

[Invention, Power, Problems to be Solved] The conventional thin film forming bag device has a structure in which the crucible body and the top cover rub against each other on the outside and side of the crucible body, as described above, to deposit materials. It was intended to be sealed and stuffed into the claw."'l'
, l: Therefore, the vapor of the vapor deposited substance easily leaks from the rubbing part, and the crucible 5. A part of the substance evaporated inside the substrate leaks from this contact area, and there is a problem that the ratio of the amount that should be originally evaporated and deposited on the substrate, that is, the evaporation efficiency decreases by 1:1.

This invention was made in order to solve the problems as described above. The purpose of the present invention is to provide a thin film forming apparatus that can increase vapor deposition efficiency.

[Means for solving problems]

The thin film forming apparatus according to the present invention has a structure in which the crucible body has an upper lid whose side wall is in sliding contact with the inner wall of the crucible body and extends to near the bottom of the crucible body. ,・(Function) In this invention, since the molten liquid of the vapor deposition substance exists in the sliding contact portion between the side wall of the upper lid and the inner wall of the crucible body,
There is almost no leakage of the vapor of the vapor deposited material from the sliding contact area,
The efficiency of vapor deposition of the vapor deposition material onto the substrate can be increased.

〔,Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a thin film forming apparatus according to an embodiment of the present invention,
In the figure, the same symbols as in FIG. 2 indicate the same parts.

Reference numeral 5a denotes an upper lid whose side wall is inserted into sliding contact with the inner wall of the crucible body 5b and reaches near the bottom of the crucible body 5b. Here, the vapor deposition substance 4 is approximately 80% of the volume of the crucible body 5b.
%, and when the vapor deposition substance 4 evaporates to some extent and becomes low, it is replenished.

Next, the effects will be explained.

The vapor deposition substance 4 heated in the crucible 5 and turned into a liquid evaporates from the liquid surface, and the vapor is ejected from the small hole 5C of the upper lid 5B and is vapor deposited on the substrate 24 placed on the top of the vacuum chamber 1. The operation is similar to that of the conventional device, but in this device, the crucible body 5b
The sliding contact area between the upper lid 5a and the upper lid 5a is filled with the melt of the vapor deposition material 4, and there is almost no leakage of the melt from the sliding contact area. In this manner, the present apparatus can significantly improve the efficiency of vapor deposition of the vapor deposition substance onto the substrate.

For example, when gold is heated to 1800°C, the gold vapor pressure in the melting device is approximately 3 Torr. In this case, pressure is required to push up the liquid in the gap, and the internal pressure is 3T.

The combined liquid column that balances with rr is about 2 mm, and it is unlikely that the gold liquid will be pushed up through the gap and leak out of the crucible. Therefore, material leakage can be almost completely eliminated. .

〔Effect of the invention〕

As described above, according to the thin film forming apparatus according to the present invention,
Since the crucible has an insert-type top lid that reaches close to the bottom of the crucible, there is no leakage of material vapor from the sliding contact between the crucible body and the top lid, which improves the efficiency of evaporation of the evaporation material onto the substrate. This has the effect of improving the yield of vapor deposition material.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing a thin film forming apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional side view showing a conventional WtPA forming apparatus. 5a... Upper lid, 5b... Crucible body, 5C...
In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a thin film forming apparatus that deposits a thin film on a substrate by ejecting the vapor of a vapor deposition material in a crucible into a vacuum chamber, the crucible that accommodates the vapor deposition material and generates the vapor of the vapor deposition material has a crucible whose side wall is a crucible. A thin film forming apparatus characterized by having an upper lid that is inserted into the crucible main body in sliding contact with the inner wall of the main body and reaches near the bottom of the crucible main body.