JPS62287617A - Apparatus for forming thin film - Google Patents

Abstract

PURPOSE:To enable evaporation to be performed at a high speed by using tungsten as the material of at least the inner surface portion of a crucible containing the evaporation material, thereby preventing chromium as the evaporation material and the crucible material from reacting even if the crucible is heated to a high temperature. CONSTITUTION:In the apparatus for forming a thin film wherein a crucible 4 is heated in a vacuum bath 1 to cause a cluster of the evaporation material to be jetted thereby forming a thin film on a substrate, the evaporation material is chromium, and at least the inner surface of the crubible 5 is consisted of tungsten. Since the material of the crucible is composed of tungsten, even if chromium which is the evaporation material is heated to a high temperature of 1500 deg.C or higher, chromium does not react with tungsten, so that stable evaporation can be performed at a high speed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a vapor deposition apparatus for forming a thin film in vacuum.

[Conventional technology]

FIG. 3 is a sectional view showing a thin film forming apparatus disclosed in, for example, Japanese Unexamined Patent Publication No. 54-9592. In the figure, 1 is a vacuum chamber, 2 is a vacuum exhaust port, 3 is an evacuation Roparve, and 4 is a vapor deposition device. The substance 5 is a crucible containing the vapor deposition substance 4, and the material is tantalum or carbon.

6 is a crucible support base, 7 is an electron bombardment filament that emits electrons to heat the crucible 5, 8 is an ionization filament that emits electrons to form the crucible 5 and the electron bombardment filament, and 12 is an ionization filament 11. Electronic extraction grid that extracts electrons, 13
14 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 electron extracted from the ionization filament 11 by the electron extraction grid 12, and 16 is an acceleration 17 is an accelerating electrode insulator that supports the accelerating electrode; 18 is a neutral cluster of the vapor deposition material 4 ejected from the crucible 5; 19 is an ionized cluster of the vapor deposition material 4 ionized by the ionized electrons 15; 20 is a neutral cluster 18 and a cluster beam containing the ionized clusters 19; 21, a shutter that blocks the cluster beam 20; 22, a shutter support rod that supports and rotates the shutter 21; 23, a shutter support rod seal portion where the shutter support rod 22 passes through the vacuum chamber 1; 24; is a substrate, 25 is a substrate holder, 26 is a substrate holder seal part, 27 is a crucible 5
This is a nozzle installed in the

Next, the operation will be explained. In a high vacuum area that is evacuated from the vacuum outlet 2 of the vacuum chamber 1 through the vacuum outlet valve 3, the crucible 5 containing the deposition material 4 is subjected to electron bombardment by electrons emitted from the electron bombardment filament 7. The vapor deposition material 4 is heated to a temperature such that the vapor pressure in the crucible 5 becomes several Torr. Next, the nozzle 27 provided in the crucible 5
The vapor of the vapor deposition material 4 is ejected into the high vacuum region from the vapor deposition material 4, and at this time, a cluster beam 20 is generated due to a supercooled state due to adiabatic expansion. By colliding the cluster beam 20 with ionized electrons 15 extracted from the ionized filament 11 by the electron extraction grid 12, the cluster is ionized and an ionized cluster 19 is formed. Some of the clusters do not collide with the ionized electrons 15 and are deposited as neutral clusters 18 onto the substrate 24 at the rate of ejection from the crucible 5. The ionization cluster 19 is
A potential difference is applied between the electron extraction grid 12 and the ionization heat shield plate 13 and the accelerating electrode 16 so that the former is positive and the latter is negative, and the particles are accelerated and deposited on the substrate 24. The shutter 21 is an opening/closing device that controls the cluster beam 20 and allows the thin film formed on the substrate 24 to have a required thickness.

[Problem that the invention seeks to solve]

As described above, in conventional thin film forming apparatuses, the crucible that houses the vapor deposition material is tantalum or carbon, so when the vapor deposition material, chromium, is heated to a high temperature of approximately 1500°C or higher, the chromium reacts with the crucible material. However, there was a problem in that pure ROM could not be deposited.

This invention was made to solve the above-mentioned problems, and provides a thin film forming device that can deposit chromium at high speed without causing any reaction between the chromium, which is the deposition substance, and the crucible material even when the crucible is heated to a high temperature. The purpose is to obtain.

[Means for solving problems]

In the thin film forming apparatus according to the present invention, at least the inner surface of the crucible containing the vapor deposition material is made of tungsten.

[Effect]

In this invention, since only tungsten comes into contact with the chromium, which is the vapor deposition material, in the crucible containing the vapor deposition material, contact with a substance that reacts with chromium and the subsequent reaction can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, numerals 1 to 3 and 6 to 27 are similar to the conventional device described above.

4 is a crucible made of chromium, which is a vapor deposition substance, and 2nd is a crucible made of tungsten.

In this example, as mentioned above, since the material of the crucible is tungsten, 15
Even at high temperatures of 00° C. or higher, chromium does not react with tungsten, and stable vapor deposition can be performed at high speed.

FIG. 2 shows another embodiment of this invention, and in this embodiment,
The crucible 29 is formed by closely adhering a thin tungsten plate 31 to the inner surface of a tantalum or carbon material 30.

In this embodiment as well, chromium, which is the vapor deposition material, does not come into contact with any substance other than tungsten, so no reaction occurs, and stable vapor deposition can be performed at high speed.

In addition, in the above embodiment, the case of a thin film forming apparatus using ion clusters has been described, but other HW forming apparatuses that require ion blating or crucibles may be used (although the same effects as in the above embodiment can be achieved). .

〔Effect of the invention〕

As described above, according to the present invention, since at least the inner surface of the crucible containing the vapor deposition material is made of tungsten, contact with a substance that reacts with chromium, which is the vapor deposition material, and the subsequent reaction are prevented, and chromium can be evaporated at high speed. It can be deposited stably.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a thin film forming apparatus according to one embodiment of the present invention, FIG. 2 is a sectional view showing a thin film forming apparatus according to another embodiment of the present invention, and FIG. 3 is a sectional view showing a conventional N film forming apparatus. FIG. 2 is a crucible made of tungsten, 29 is a crucible for vapor deposition, 30 is a Kuntal or carbon material, and 31 is a tungsten thin plate. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A thin film forming apparatus that heats a crucible containing a vapor deposition material in a vacuum chamber to eject clusters of the vapor deposition material to form a thin film on a substrate, wherein the vapor deposition material is chromium, and at least the inner surface of the crucible A thin film forming apparatus characterized in that the material is made of tungsten. (2) The thin film forming apparatus according to claim 1, wherein the entire crucible is made of tungsten. (3) The thin film forming apparatus according to claim 1, wherein the crucible has a thin tungsten plate attached to the inner surface of a tantalum or carbon material.