JPH02250958A - Vacuum deposition equipment - Google Patents

Abstract

PURPOSE:To prevent contamination of the vapor deposition material due to peeling of the inner wall of a crucible at a time for coagulating and shrinking this vapor deposition material by constituting a vacuum deposition device so that the crucible housing the vapor deposition material can be closed and the vapor deposition material is heated in such a state that closure is held and also inert gas can be supplied into the closed vessel. CONSTITUTION:The vapor deposition material 13 is heated by a heater 14 via a crucible 12 and evaporated and a thin film is formed on a substrate 11. Then in the case of replacement, etc., of the substrate 11, a pneumatic cylinder 24 is actuated to the direction shown in an arrow D in such a state that the material 13 has been melted by electrifying the heater 14. A cover 21 is rotated to the lower direction, pressed and brought into contact with an O-ring 20 and thereafter a vacuum vessel 10 is leaked. Then a valve 19 is opened and inert gas is introduced while measuring the pressure of the space 26 by a vacuum indicator 18. The valve 19 is closed when the pressure of the space is regulated to the prescribed pressure. Evaporation of the material 13 is inhibited by pressure rise of inert gas. Therefore contamination of the material 13 resulting from peeling of the inner wall of the crucible 12 can be avoided by preventing coagulation and shrinkage of hte material 13.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a vacuum evaporation apparatus.

Conventional technology In vacuum evaporation equipment, when air is introduced into the vacuum container for substrate replacement or internal maintenance, when there is a so-called leak, the evaporation material comes into contact with the air and reacts with oxygen and moisture in the air. Otherwise, there is a problem that a high-quality thin film cannot be formed due to contamination caused by adsorption of these substances.

In order to deal with this issue, for example, Japanese Patent Laid-Open No. 63-2
As shown in Japanese Patent No. 70457, a means for maintaining the vapor deposition material in a vacuum atmosphere was provided so that the vapor deposition material did not come into contact with the atmosphere when the atmosphere was introduced into the vacuum container.

Problems to be Solved by the Invention However, although the above-mentioned conventional method is effective against contamination of the vapor deposition material from the atmosphere, it is not effective against the problem described in FIG. 3 shown below.

In FIG. 3, the vapor deposition material 2, which has been deposited into the crucible 1 after completion of vapor deposition, begins to solidify at the portion where it contacts the inner wall 3 of the crucible. When the vapor deposition material 2 is a high melting point metal or the like, a sintered ceramic is usually used for the melt 1.

Since the surface of the sintered ceramic is smooth, the vapor deposition material 2 solidifies while entering the unevenness 4. The vapor deposition material 2 begins to shrink due to a decrease in temperature. Then, the vapor deposition material 2 that has entered the unevenness 4 of the crucible 1 is pulled to the center of the vapor deposition material 2 while peeling off the inner wall 3 of the crucible, and the surface of the vapor deposition material 2 that was in contact with the crucible 1 is drawn as shown in the opening in Figure 3. Broken pieces 6 of the crucible material will adhere.

Further, even if the surface of the crucible 10 is smooth, such peeling may occur due to chemical affinity between the vapor deposition material 2 and the crucible 1. When the vapor deposition material 2 is heated and melted again for vapor deposition, the broken pieces 6 float on the surface of the vapor deposition material 2 as shown in FIG. 3C, since ceramics are usually lighter than metals.

This effectively reduces the evaporation area of the evaporation material 2 and reduces the film formation rate, or in the case of electron beam evaporation, the electron beam hits the fragments 6, causing the fragments 6 to evaporate and impurities in the thin film. There were major issues that could not be addressed with conventional methods, such as the intrusion of particles and the deterioration of the quality of thin films.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problem by preventing the inner wall of the crucible from being peeled off, and to provide a vacuum evaporation apparatus capable of forming a high-quality thin film.

Means for Solving the Problems And in order to solve the above problems, the present invention heats the vapor deposition material in a state in which the crucible containing the vapor deposition material is kept hermetically sealed by a sealing means that can selectively maintain the crucible in a closed state and an open state. At the same time, an inert gas is supplied into the sealed container.

Function The present invention solves the above problems by preventing the solidification and shrinkage of the vapor deposition material so that the inner wall of the crucible is not peeled off, and also by supplying an inert gas to reduce the pressure inside the closed container. The temperature is raised to a state where evaporation of the heated vapor deposition material can be suppressed or prevented. Therefore, the consumption of the evaporation material due to heating and the deposition of vapor of the evaporation material on the inside of the closed container are less likely to cause contamination.

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

FIG. 1 is a sectional view showing the overall configuration of the present invention.

In FIG. 1, reference numeral 10 denotes a vacuum vessel, and a substrate mount 27 for supporting the substrate 11 is fixed to the upper part. 12 is a crucible for storing a vapor deposition material 13, and 14 is a heater supported by a heat insulating material 16. 17 is an inert gas passage, 18 is a vacuum gauge, and 19 is a valve. Reference numeral 21 denotes an opening/closing lid having a recess 21-1, which is fixed to a shaft 22, and a pinion 28 is fixed to one end of the shaft 22. The shaft 22 is rotatably supported by bearings 23 at both ends. Binion 28 is vacuum container 1
By the reciprocating motion of the air cylinder 24 provided on the outside of the rack 24 in the directions of arrows C and D, the motion is transmitted to the rack 26, which rotates in the directions of arrows E and F. Note that a known evacuation means for evacuating the vacuum container 1o is omitted.

Next, the operation will be explained.

Film formation is performed as follows with the air cylinder 24 operated in the direction of arrow C and the lid 21 opened in the direction of arrow E. The heater 14 is energized to heat the vapor deposition material 13 through the crucible 12 and evaporate it to form a thin film on the substrate 11 . If the vapor deposition material 13 is a material with high vapor pressure such as a high melting point metal,
Although not shown, a known electron beam heating means may be used, or other heating means may be used, or the heater 14 may be used in combination with them.

Next, the vacuum container 1 is
When leaking 0, the heater 14 is energized and the vapor deposition material 1 is leaked.
3, while maintaining the melting state, the air cylinder 24 is first operated in the direction of the arrow, and the lid 21 is rotated in the direction F to bring it into pressure contact with the O-ring 20. Next, the vacuum container 10 is leaked. Then, as the pressure inside the vacuum container becomes atmospheric, the pressure inside the vacuum container becomes higher than the pressure in the space 26 sealed by the lid 21, and finally the lid 21 is pressed by atmospheric pressure and is tightly fixed to the wreath 16. Next, the valve 19 is opened and a so-called inert gas that does not react with the melted vapor deposition material 13 is introduced into the space 2.
6 is introduced while measuring it with a vacuum gauge 18, and when the required pressure is reached, the valve 19 is closed.

As the pressure of the inert gas introduced into the space 26 increases, the evaporation of the vapor deposition material 13 is suppressed, and when the pressure becomes higher than the vapor pressure of the vapor deposition material 13, the evaporation is completely suppressed. Usually, the vapor pressure varies depending on the type of vapor deposition material 13 and the heating temperature, but since it is 10 -5 Torr to 10 Torr, the pressure in the space 26 will not become higher than atmospheric pressure and the lid 21 will not open.

Therefore, since the vapor deposition material 13 does not undergo solidification shrinkage, the inner wall of the crucible 12 is not peeled off as in the conventional case. Furthermore, problems such as the vapor deposition material 13 evaporating into the space 26 and being consumed, and the lid 21 being contaminated with a film attached thereto are less likely to occur.

Next, other embodiments of the present invention will be described.

Components common to those in FIG. 1 are given the same numbers and their explanations will be omitted.

In the embodiment described above, a rotatable lid 21 is used as one element of the means for sealing the Haruppo 12, but a sliding lid may also be used.

In FIG. 2, 3o is a subchamber partitioned off by a known gate valve 31. 32 is a connecting rod between the air cylinder 33 and the hearth 16. Vapor deposition is carried out by lifting the hearth 16 up to the broken line inside the vacuum vessel 10 with the air cylinder 33 with the gate valve 31 open.
When leaking, the hearth 16 is lowered to the solid line position within 3 degrees of the sub-chamber by the air cylinder 33, the gate valve 31 is closed, the vapor deposition material 13 is heated by the heater 14 as described above, and an inert gas is introduced. . With this configuration, the hearth 16 does not remain inside the vacuum container 10, so the vacuum container 10
It has the advantage that internal maintenance etc. can be easily performed.

In the above description, the heater 14 is used as a heating means for preventing the evaporation material from shrinking due to confusion, but the present invention is not limited to this, and induction heating or electron beam heating may be used.

Effects of the Invention As described above, according to the present invention, when a leak occurs in a vacuum container, the crucible is sealed while heating the vapor deposition material, and an inert gas is supplied, thereby evaporating the heated vapor deposition material inside the sealed container. By suppressing or suppressing this, it is possible to prevent the inner wall of the crucible from being peeled off due to solidification shrinkage of the vapor deposition material. As a result, it is possible to prevent contamination of the vapor deposition material by fragments torn off from the inner wall of the crucible, and to form a stable, high-quality thin film.

[Brief explanation of drawings]

Fig. 1 is a partially sectional front view of an embodiment of the present invention, Fig. 2 is a partially sectional front view of another embodiment of the invention, and Fig. 3 is a front view showing a cross section for explaining a conventional example. It is a diagram. 1o...Vacuum container, 11...Substrate, 1
2... Crucible, 13... Vapor deposition material, 1
4...Heater, 17...Inert gas passage, 18...Vacuum gauge, 19...Valve, 2
o...o-ring, 21...lid. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (2)

[Claims] (1) A vacuum container, a substrate and a crucible provided in the vacuum container, a first heating means for heating and vapor depositing the vapor deposition material stored in the crucible to form a thin film on the substrate, and the crucible. a sealing means capable of selectively holding the crucible in a closed state and an open state; a second heating means for heating the vapor deposition material while the crucible is held tightly sealed by the sealing means; and a means for supplying an inert gas. (2) The vacuum evaporation apparatus according to claim 1, wherein the first and second heating means are the same heating means.