JPH089770B2 - Vacuum deposition equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a vapor deposition apparatus used for vacuum vapor deposition or the like, and in particular, a vapor guide as a vapor flow control wall surface between a substrate for forming a thin film and a crucible containing a vapor deposition substance. The present invention relates to a vacuum vapor deposition device using a duct.

[Conventional technology]

In recent years, a so-called metal thin film type magnetic recording medium in which a ferromagnetic material is deposited as a thin film on a substrate has attracted attention as a recording medium having a much higher recording density. Such a metal thin film type magnetic recording medium is usually manufactured by forming a thin film on a substrate by vapor deposition, sputtering or the like in a vacuum state.

As a conventional vapor deposition device, a ferromagnetic material contained in a crucible is heated and evaporated by an electron beam that can be emitted from an electron gun, and the ferromagnetic material is vapor-deposited on a polymer forming substrate that runs on the upper part of the crucible. The method of making is done.

However, this method requires a relatively large space above the crucible to secure the passage of the electron beam emitted from the electron gun to the crucible. For this reason, even in the case where a vapor flow control means constituted of, for example, an appropriate wall surface is provided in the upper part of the crucible to suppress the diffusion of evaporation from the crucible,
Since a gap must be formed between the vapor flow control means and the crucible, the vapor of the ferromagnetic material is scattered and the vapor deposition efficiency is not good, and the vapor flow control means has been improved. (See, for example, Japanese Patent Laid-Open No. 57-194252) Furthermore, as a method for improving the vapor deposition efficiency, the present applicant has previously shown a vacuum container (not shown) as shown in FIG.
A vapor flow control means 4 is provided between a substrate 1 and a crucible 3 made of a ferromagnetic material as a vapor deposition material 2 under a so-called vacuum, and the vapor flow control means 4 extends directly above the crucible 3. A vapor deposition apparatus has been proposed in which the vapor flow control means 4 is arranged so as to completely surround the periphery of the vapor flow, high frequency induction heating is used as the heating means 5, and the incident angle regulating mask 6 is provided.

[Problems to be solved by the invention]

However, in such an evaporator, although the evaporation efficiency is significantly increased, if the area of the evaporation surface (So) of the crucible is increased in order to increase the evaporation rate in order to improve the productivity, the incident angle of the evaporation flow is taken into consideration. Then, the wall surface of the steam flow control means must be lengthened, and the crucible and the steam flow control means become large.

In addition, the power consumption for increasing the heating of the large-sized crucible and steam flow control means becomes very large. For this increase in energy consumption, the crucible and steam flow control means due to the higher steam pressure There is a drawback that the vapor deposition efficiency is not improved because the collision and scattering of particles in the inside increase and the directivity of vapor decreases.

Furthermore, in the conventional configuration, there is a limitation that the evaporation direction is limited to just above.

It is an object of the present invention to eliminate the above-mentioned drawbacks of the conventional apparatus, and to effectively guide a vapor molecule flow of a vapor deposition substance in a desired direction to a substrate to provide a vacuum vapor deposition apparatus with high vapor deposition efficiency. I am trying.

[Means for solving problems]

As a result of intensive studies by the present inventor, in the conventional crucible, the upper part of the crucible was opened and the surroundings of the crucible were surrounded by evaporation flow control means between the base and the crucible. By forming an enclosed crucible and guiding a vapor guide duct for guiding a vapor deposition substance from a part of the crucible wall, and further by controlling the inner wall surface temperature of the crucible and the vapor guide duct,
It has been found that the vapor deposition material can be realized as a highly directional vapor molecular flow in any direction.

That is, an object of the present invention is to store a vapor deposition material in a vacuum container and to cover the upper side of the vapor deposition material almost completely, and to completely seal the crucible leaving an opening for vaporization of the vapor deposition material, and the crucible. Has a vapor guide duct that extends from the opening provided above the liquid surface of the vapor deposition substance toward the base body that forms the vapor deposition film and guides vapor of the vapor deposition substance, and to the crucible. Is provided over substantially the entire outer circumference of the crucible with heating means for keeping the inner wall temperature above the temperature at which the vapor deposition material can be vaporized, and the vapor guide duct has an inner surface temperature not lower than the melting point of the vapor deposition material and It is achieved by a vacuum vapor deposition apparatus characterized in that a heating means is provided for keeping the vapor deposition substance attached to the inner surface of the guide duct in a state of being melted in the crucible so as to be fluidized.

Further, the area of the opening continuing to the vapor guide duct is 30 with respect to the evaporation area of the vapor deposition material in the crucible.
% Or less is preferable.

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

FIG. 1 is a vertical sectional view of essential parts of a crucible and a steam guide duct in a vacuum vapor deposition apparatus of the present invention.

In FIG. 1, a vapor deposition material 2 is heated in a crucible 8 by a crucible heating means 9 to be evaporated, and steam is vaporized from a part of an opening 10 in a wall of the crucible to a steam guide duct.
Through 11 towards the substrate 1. In this case, crucible 8
A heating means 9 is provided on the outer circumference (upper and lower surfaces and substantially the entire six surfaces of the side surfaces) of the crucible for maintaining the inner wall temperature of the crucible at, for example, a boiling point temperature or higher at which vapor deposition substance 2 is hardly condensed on the inner wall. Further, on the outer circumference of the steam guide duct 11, heating means for keeping the temperature of the inner surface of the duct above the melting point of the vapor deposition substance 2 and in the vicinity thereof.
Twelve are provided.

Further, the steam guide duct 11 may be fixed in a desired direction in general, but is adjustable so that it can be attached in any direction from the opening 10 of the crucible and vaporized if necessary. .

The crucible 8, the steam guide duct 11, the substrate 1, the heating means 9 and 12 are housed in a vacuum container (not shown).

The apparatus of the present embodiment can be widely used as a general vacuum vapor deposition apparatus, but particularly when used in a method of manufacturing a magnetic recording medium, Fe, Co,
Ni and these alloys or those to which elements such as V, Mo, Mn and Pd are added according to the purpose are used. If necessary, N,
O or the like may be contained in the metal film.

The material of the crucible 8 of the present embodiment is not particularly limited, but for example, MgO, ZrO ₂ , Al ₂ O ₃ , CaO, Y ₂ O
₃ , ThO ₂ , BN, BeO, CaO stabilized ZrO ₂ (90% to 98% of ZrO ₂
+ CaO is 10% to 2%), Y ₂ O ₃ stabilized ZrO ₂ (ZrO ₂ is 90% to 9%)
Ceramics such as 8% + Y ₂ O ₃ is 10% to 2%) and other heat resistant materials can be used.

The vapor guide duct 11 in the present invention is heated to a temperature higher than the melting point of the vapor deposition material, and the vapor deposition material adhering to the surface is melted and flowed into the crucible. Therefore, the temperature may be lower than that of the crucible 8. The same material can be used.

As the heating means 9 of the crucible 8 and the heating means 12 of the steam guide duct 11 in the present invention, it is preferable to use high frequency induction heating means. A frequency of 50 to 200 KHZ and an output capacity of 20 KW to 100 KW are used as conditions for high frequency induction heating.

The substrate used in the present invention is not particularly limited as a non-magnetic material, and a commonly used one can be used.

As a specific example, polyethylene terephthalate (PE
T), polypropylene, polycarbonate, polyethylene phthalate, polyamide, polyamide imide, polyimide, etc., which is a polymer molded body substrate, and may be a non-magnetic metal material such as aluminum foil or stainless steel foil depending on the purpose. The thickness of the substrate is generally 3 to 50 μm, preferably 5 to 30 μm. When the present invention is used as a method for producing a magnetic material, the substrate is vapor-deposited by traveling in a vacuum container.

 The operation of this embodiment will be described below.

Thus, in order to melt and evaporate the evaporation material in the vacuum container, the crucible 8 having the opening 10 that is considerably smaller than the evaporation area of the liquid surface S ₀ of the evaporation material, and vapor from this opening 10 to the substrate 1. And a steam guide duct 11 for guiding. The crucible 8 is provided with a heating means 9 for keeping the inner wall temperature of the vapor deposition substance above the concentration of the vaporized substance on the inner wall and a heating means 12 for keeping the inner surface temperature of the crucible 8 at the melting point of the vaporized substance or more. Therefore, first, inside the crucible that evaporates the evaporation material 2 (the space surrounded by the liquid surface of the evaporation material and the left, right, front, rear, and upper wall surfaces), so-called free molecular motion can be realized, while the vapor guide duct.
In 11, heating is performed at a temperature lower than in the crucible (the temperature at which the material attached to the inner wall of the duct melts), the vapor deposition material attached to the inner wall of the duct in the duct melts and falls into the crucible, and As in the crucible, the molecular air flow in the duct is stably guided toward the substrate 1 without being further activated by the external energy and without further activation of the molecular motion.

Further, it is desirable to keep the ratio of the cross-sectional area S of the guide duct 11 from which the liquid surface S ₀ evaporates to S / S ₀ <0.3.

Further, by keeping the inner wall temperature of the crucible at a temperature at which vapor deposition molecules hardly condense (evaporation temperature or higher), vapor deposition molecules in the crucible fly in random directions.

Needless to say, the inner wall temperature To of the crucible at this time depends on the deposition material, but the relation of τ ₀ exp (Ed / kTo) <τ ₁ to the adsorption energy Ed of the deposition material to the inner wall material of the crucible is T. give.

However, τ ₁ ; average time for particles to fly in crucible Te; temperature of vapor deposition particles L; mean free path m; mass of vapor deposition particles k; Boltzmann constant, Is.

On the other hand, it is desirable that the vapor guide duct has a high adhesion rate in order to orient the vapor deposition particles, but sticking to the inner wall surface causes the vapor guide duct to be blocked by the deposition of vapor deposition particles. Undesired, so melting point Tm
It needs to be kept reasonable.

The adhesion rate at this time is not always 1, but generally 0.5
The above can be a substrate.

Since the heating temperature is high in the space inside the crucible as described above, the opening 10 forms a substantial liquid surface. This means that the opening 10 can be provided anywhere as long as it faces the space, and the degree of freedom in forming the opening 10 is increased.

By the evaporation method having such characteristics, the vapor guide duct 11 may be attached at any position corresponding to the space portion of the crucible 8 (the space surrounded by the liquid surface of the vapor deposition material and the left, right, front, rear, and upper wall surfaces). Moreover, it is possible to extract a molecular flow having a high directivity in an arbitrary direction.

〔Example〕

As the crucible, a crucible with an evaporation surface of 50 mmφ is used. The high frequency induction heating power source has a frequency of 200 KHZ, the output capacity is 25 KW, the polymer molded body has a polyethylene terephthalate film of 100 mm width, 13 μm thick, and the vapor deposition drum has a diameter of 300 mm (surface temperature of about 0 ° C ), The vapor guide duct was taken out with a width of 20 mmφ, and vapor deposition was performed with the vapor deposition guide duct outlet of vapor deposition molecules being 120 mm × 10 mm.

As a result of vaporizing Co at a film pressure of about 1500Å at a conveying speed of the polymer molded body of 15 m / min, a vapor deposition efficiency of 25% was obtained. At this time, the inner wall surface of the crucible was 2000 ° C and the inner surface of the vapor deposition guide duct was
Maintained at 1600 ° C.

〔The invention's effect〕

As described above, the present invention provides a crucible having an opening that is considerably smaller than the size of the evaporation area of the liquid surface of the vapor deposition material in order to melt and vaporize the vapor deposition material, and a vapor guide duct that guides vapor from this opening to the substrate. And a heating means for keeping the temperature of the inner wall of the crucible above the temperature at which the vapor deposition substance hardly condenses on the inner wall, and a heating means for keeping the temperature of the vapor guide duct above the melting point of the vaporized substance.

Therefore, in the inner space of the crucible for evaporating the evaporating substance, free molecular motion of evaporating particles can be realized, while in the guide duct, the material adhering to the inner wall of the duct is heated to a temperature at which it melts, The vapor deposition material adhering to the inner wall of the duct inside the duct melts and falls into the crucible, and the molecular airflow inside the duct does not receive energy from the outside as in the crucible, and the molecular motion is not further activated. Since the vapor deposition material is stably guided toward the substrate, the vapor deposition material can be realized in a highly directional vapor molecular flow in an arbitrary direction, whereby the vapor deposition efficiency is remarkably improved, and the guide duct in the vapor deposition apparatus is conventionally used. It has a smaller size and does not require a higher heating temperature than necessary, so it is possible to promote compactness and minimize power consumption. It was.

[Brief description of drawings]

FIG. 1 is a partial side sectional view for explaining a crucible and a vapor guide duct portion of a vapor deposition apparatus of the present invention, and FIG. 2 is a partial side sectional view for explaining a crucible and a vapor flow control means of a conventional vapor deposition apparatus. Is. 1 ... Substrate, 2 ... Deposition material 3 ... Crucible, 4 ... Vapor flow control wall surface 5 ... Heating means, So ... Evaporation surface 6 ... Incident angle control mask 8 ... Crucible 9 ... Heating means ( Electric furnace) 10 …… Opening 11 …… Steam guide duct 12 …… Heating means (for steam guide duct)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-145168 (JP, A) JP-B 49-29463 (JP, B2) JP-B 57-50874 (JP, B2)

Claims (2)

[Claims] 1. A crucible that is configured to store a vapor deposition material in a vacuum container and to cover the upper side of the vacuum vessel and to completely seal the vapor deposition material leaving an opening for vaporization of the vapor deposition material, and a wall surface of the crucible. The crucible has a vapor guide duct that extends from the opening provided above the liquid surface of the vapor deposition material toward the substrate that forms the vapor deposition film and guides vapor of the vapor deposition material, and the crucible has an inner wall thereof. Heating means for maintaining the temperature above the temperature that enables vaporization of the vapor deposition material is provided over substantially the entire outer circumference of the crucible, and the vapor guide duct has an inner surface temperature that is equal to or higher than the melting point of the vapor deposition material and that of the guide duct. A vacuum vapor deposition apparatus comprising heating means for maintaining a temperature at which a vapor deposition substance attached to an inner surface of the crucible is melted in a melted state. 2. The area of the opening continuing to the vapor guide duct is 30% or less of the evaporation area of the vapor deposition material in the crucible.
The vacuum vapor deposition device according to the item.