JPH02104659A - Thin film manufacturing equipment - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film manufacturing apparatus for melting a material to generate steam and depositing the material on a substrate to form a thin film.

Conventional Techniques Conventionally, sputtering methods and vacuum evaporation methods have been used to form thin films on substrates. Considering mass productivity, a high deposition rate is desired, so the latter is more suitable. Methods for melting materials include resistance heating and electron guns (hereinafter referred to as E).
EB) which involves heating but can be applied to high melting point materials
Heating has been frequently used in recent years.

FIG. 2 shows a schematic structural diagram of a conventional metal thin film deposition apparatus. M in the installation hearth 2 cooled by the cooler 1
An evaporation crucible 3 made of a heat-resistant material such as qO is installed, and a metal 4 is placed inside. Metal 4 is melted by EBs. Metal vapor generated from the molten metal 4 is deposited on the substrate 6 to form a metal thin film. 7 is a mask, and 8 is a vacuum chamber wall.

Problems to be Solved by the Invention However, the large EB input input into the evaporation crucible, for example, the amount of heat Q1 used to evaporate the metal, the amount of heat Q2 due to radiation from the surface of the hot molten metal in the evaporation crucible, and the amount of heat Q2 from the back side of the evaporation crucible. Roughly divided into the amount of heat lost to the installation hearth 2 Q3, the amount of heat Q1 used for net metal evaporation is EB
The current situation is that the large input is about 2Q% and is not being used effectively.

Further, the radiant heat Q2 from the surface of the molten metal in the evaporation crucible directly irradiates the substrate 6 at the negative portion, and irradiates the surrounding vacuum chamber 8 at the other portion, is absorbed, and re-radiates to the substrate 6. Alternatively, the light is reflected by the vacuum chamber 8 and irradiates the substrate 6. As a result, the heat received by the substrate 6 is greater from the radiant heat from the evaporation source than from the condensation heat of the metal vapor, and thermal deformation of the substrate is largely due to the radiant heat. It has also been found that the loss of heat Q3 from the back surface of the evaporation crucible is not only due to heat conduction, but also due to radiation when viewed microscopically. If the heat loss from the back side is large, in extreme cases, only the part of the molten metal surface that is irradiated with EB will be at a high temperature, and the temperature difference with the surrounding area will be large and the molten metal surface temperature distribution will be uneven6.As a result, the molten metal surface temperature will change. Since the corresponding saturated vapor pressure distribution becomes non-uniform, the molten metal level fluctuates and molten metal flies. A problem occurred in that the flying molten metal (hereinafter referred to as "splash") adhered to the substrate 6, and the degree of completion of the metal thin film was extremely reduced.

An object of the present invention is to solve the problems of the prior art.

SUMMARY OF THE INVENTION The present invention includes an evaporation crucible for melting material supported on an installation hearth to generate vapor of the material, a substrate, and means for reducing radiant heat from the evaporation crucible.

One means of reducing radiant heat is to provide a wall of low emissivity material between the evaporation crucible and the substrate that is concave with respect to the evaporation crucible.

Alternatively, as a means to reduce radiant heat, the evaporation crucible is housed in a container made of a low emissivity material and a gap is provided between it and the installation hearth.

Operation The present invention operates as follows by means of the above-mentioned means. By reducing the radiant heat from the surface of the molten metal in the evaporation crucible, thermal deformation of the substrate can be prevented. Furthermore, since the radiant heat from the back side of the evaporation crucible is reduced, heat loss from the back side of the evaporation crucible is reduced and the heat insulation effect is improved. Therefore, not only the input EB power is effectively used, but also the temperature distribution on the surface of the molten metal is made uniform, so that splashes are less likely to occur and a thin film with a high degree of perfection is formed.

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

FIG. 1 is a structural diagram showing an outline of a thin film manufacturing apparatus according to an embodiment of the present invention.

In the figure, a cooler 1 and an installation hearth 2. Evaporation crucible 3
．． Material 4. Substrate 6. The mask 7 and the vacuum chamber wall 8 are the same components as in FIG. 2 described above, and are indicated by the same numbers.

A concave mirror 9 installed between the evaporation crucible 3 and the substrate 6 has a mirror finish with a surface roughness of about 0.2 S, and is arranged so as to be concave with respect to the evaporation crucible 3. Further, the evaporation melt 3 is housed in a container 1o made of a high melting point material (for example, tungsten, molybdenum, etc.), and the outer surface of the container 10 is also mirror-finished 9, with an emissivity of 0. A low emissivity surface of about 2 to 0.3 has been achieved. A gap 11 is formed between the installation hearth 2 and the installation hearth 2.

Next, the operation of the above embodiment will be explained.

The material 4 in the evaporation crucible 3 is melted by EB (non-oral transfer), and the generated vapor is deposited on the substrate 6 to form a thin film. The heat received by the substrate 6 at this time is the condensation heat Q1 of the steam and the radiant heat Q2 from the surface of the molten metal in the evaporation crucible. Of the radiant heat Q2, the radiant heat other than the heat that directly enters the substrate 6 enters the concave mirror 9. However, since the surface of the concave mirror 9 has a mirror finish and is concave with respect to the evaporation crucible 3, the radiant heat Q2 incident on the concave mirror 9 is reflected and does not enter the substrate 6, but on the molten metal surface of the evaporation crucible. Re-enter. As a result, the radiant heat Q2 received by the substrate 6 is reduced, and thermal deformation of the substrate 6 is reduced.

Furthermore, since a vacuum gap 11 exists between the container 1o in which the evaporation crucible 3 is stored and the installation hearth 2, convection,
There is almost no heat loss due to conduction.

Heat loss Q3 due to radiation has an emissivity of 0 on the outer surface of the container 11.
．． Since a low emissivity surface of about 2 to 0.3 has been achieved,
greatly reduced. Therefore, in addition to the reduction in Q2, a very high heat insulating effect is exhibited. As a result, the temperature distribution on the surface of the molten metal in the evaporation crucible is made uniform, and fluctuations in the molten metal level due to the saturated vapor pressure difference are reduced, making it difficult to generate splash and making it possible to form a highly complete thin film.

In addition, the reduction in radiant heat improves insulation, so the EB required to ensure the same evaporation rate compared to the conventional configuration is
It requires less power and is highly effective in terms of energy conservation. Furthermore, since the temperature distribution on the surface of the molten metal is made uniform, the evaporation rate distribution is also made uniform, and it is also possible to make the film thickness distribution uniform even on a large-area substrate.

As will be apparent from the detailed description of the invention, the present invention comprises an evaporation crucible for melting a material and generating vapor of the material, a substrate, and means for reducing radiant heat from the evaporation crucible. Since thermal deformation of the substrate is prevented, temperature distribution on the surface of the molten metal is made uniform to reduce fluctuations in the molten metal level, and occurrence of splash is prevented, a highly complete thin film can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram schematically showing a thin film manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a structural diagram schematically showing a conventional manufacturing apparatus. 1...Cooler, 2...Installation hearth, 3
...Eye...Evaporation crucible, 6...Substrate, 7...
...Mask, 8.. Vacuum chamber wall, 9..Concave mirror, 1o..Low emissivity material container. Name of agent: Patent attorney Shige Awano, Takashi Haga 16th
1 Fig. 9 - Concave mirror 1 o - I Emissivity material container 1]... Gap 2 Fig. 1 -> Cooling device 2... Installation hearth 3 - Steaming white crucible 2]

Claims (3)

[Claims] (1) A thin film manufacturing apparatus comprising an evaporation crucible that melts a material supported by an installation hearth to generate material vapor, a substrate on which the vapor is deposited, and means for reducing radiant heat from the evaporation crucible. (2) The thin film manufacturing apparatus according to claim 1, further comprising a wall of high reflectance material that is concave with respect to the evaporation crucible and is provided between the evaporation crucible and the substrate. (3) The thin film manufacturing apparatus according to claim 1, wherein a gap is provided between the evaporation crucible housed in a low emissivity material container and the installation hearth.