JPH09228033A - Formation of thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of reducing an energy source, capable of the continuous repetition of impurity removing treatment and film forming treatment and enabling efficient floating impurity removing treatment in an energy beam heating type vacuum vapor deposition method. SOLUTION: In a method in which a vacuum depositing material in a crucible is irradiated with an energy beam in a vacuum, by which the vacuum depositing material is heated, is melted to evaporate and is vacuum-deposited on a base material to form a thin film on the base material, in the suitable process from the start of the melting to the film formation, in the case there occurs the need of removing impurities floating on the soln. surface of a melting soln. in the crucible, the energy beam emitted from a single energy beam source is regulated to an energy level higher than the energy level at the time of the film formation and is applied to the impurities to remove the foating impurities.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an energy beam heating type vacuum deposition method, and more specifically,
When depositing a film on a substrate by irradiating an energy beam such as an electron beam onto a material to be deposited (hereinafter referred to as vapor deposition material) under vacuum and heating the material, the liquid level of the molten vapor deposition material in the crucible is The present invention relates to a method for forming a film while removing floating impurities.

[0002]

2. Description of the Related Art The vacuum vapor deposition method is a method in which a vapor deposition material is heated, melted and vaporized in a high vacuum to be deposited (vapor deposited) as a thin film on the surface of a substrate to be vapor-deposited such as a plate. Generally, in the vacuum vapor deposition method, impurities such as metal oxides attached to the surface of the vapor deposition material float on the liquid surface of the molten material (melt liquid) obtained by melting the vapor deposition material, and during film formation. Evaporated particles of the impurity component are mixed in the thin film, so that defects are likely to occur in the thin film. Further, the above-mentioned impurities become extremely high in temperature due to the irradiation of the energy beam. Therefore, when the high-temperature impurities come into contact with the molten liquid, the molten liquid causes bumping and adheres to the substrate as droplets. Therefore, there is a problem that a uniform thin film cannot be formed.

Therefore, in order to solve the above problems, a method of removing oxygen gas and oxide film which are impurities on the surface of the vapor deposition material by ion bombarding with a reducing gas plasma before heating the vapor deposition material (Japanese Patent Application Laid-Open No. Hei 10-1999) No. 3-236465), a crucible containing a vapor deposition material melted by resistance heating is vibrated by an exciter to float oxides and bubbles as impurities in the melt, and A method of evaporating by irradiating a laser beam (see Japanese Patent Laid-Open No. 4-247866) has been proposed.

[0004]

However, in the above method using reducing gas plasma, it is impossible to remove impurities in a short time because the reduction treatment of impurities requires more than 5 minutes. However, it is inconvenient because the removal process cannot be performed even if impurities are generated after melting the vapor deposition material because the impurity removal process cannot be performed. A new reduction is performed before heating the material each time one process from impurity removal to film formation is completed. Since it takes time to introduce a reactive gas to generate plasma, there is a problem that efficiency is low.

Further, in the method of vibrating with the above exciter,
Impurity removal efficiency is poor because the suspended solids of impurities are scattered on the liquid surface of the melt. At least two energy sources for thin film formation and laser oscillation sources for impurity removal are required, resulting in equipment cost. There is a problem in that the process is bulky, and the impurity removal process and the film formation process cannot be repeated continuously, so that the efficiency of these processes is poor.

In view of the above, the present invention eliminates the inclusion of impurities in a thin film and the adhesion of molten liquid droplets to a substrate in the energy beam heating type vacuum deposition method, and enables the number of energy sources to be reduced, thereby removing impurities. It is an object of the present invention to provide a method that enables continuous repetition of treatment and film formation treatment and makes the impurity removal treatment efficient.

[0007]

In order to solve the above problems, a thin film forming method by energy beam heating type vacuum vapor deposition according to the present invention comprises irradiating a vapor deposition material in a crucible under a vacuum with an energy beam. In the method of forming a thin film on the surface of the substrate by heating the vapor deposition material to melt and evaporate it to form a thin film on the surface of the substrate, melting in the crucible is performed in an appropriate process from melting of the vapor deposition material to film formation. When it becomes necessary to remove impurities floating on the liquid surface of the liquid, by irradiating the impurities with the energy beam emitted from a single energy beam source at an energy level higher than the energy level during film formation. It is characterized in that the impurities are removed.

In this case, continuous vapor deposition can be performed by alternately repeating the high energy level impurity removing process and the low energy level film forming process. It is better to avoid impurities floating freely around the surface of the melt as much as possible. Therefore, in order to enable such a thing, in the method of the present invention, first, the surface of the melt is Impurities floating on the surface of the liquid are collected and removed at a specific place on the surface of the liquid. Secondly, by making the crucible a structure in which the vapor deposition material supply side and the vaporization side are separated, it is possible to prevent impurities generated during the vapor deposition material supply from flowing out to the vaporization side, and The emitted energy beam is irradiated to the supply side and the evaporation side while changing the energy level of the energy beam.

In the first method, the crucible is rotated in a horizontal plane or the crucible is vibrated to collect impurities at a specific place. At this time, the center of rotation may be a center position inside the crucible, an eccentric position, or a position outside the crucible. Although not particularly limited, an eccentric position is preferable. There is a method of applying vibration from one side of the crucible or from two opposite sides. Although not particularly limited, it is preferable to provide a vibrator on one side. Even if the vibrator is provided on one side, it is preferable to use a plurality of vibrators and to slightly separate the intervals so that the vibration applying direction of each vibrator converges to one point on the opposite side of the crucible. More preferable. In the first method, it is preferable to provide the crucible with a stirring means such as a blade provided at the bottom of the crucible or the like so that the impurities can easily float on the liquid surface.

In the second method, the inside of the crucible having a single-chamber structure is divided into a supply side and an evaporation side of the vapor deposition material by a partition, or two supply side and evaporation side tanks are connected by a pipe. In the latter case, it is preferable that the crucible has a structure capable of heating itself in order to prevent the melt from solidifying due to the temperature decrease on the side not irradiated with the energy beam. In the present invention, although not particularly limited, the energy level during the impurity removing process is set to be 2 to 1000 times the energy level during the film forming process, and the energy beam irradiated during the impurity removing process is pulsed. That is, before the impurity removal process, the irradiation of the energy beam is once stopped and the molten liquid is cooled to such an extent that it does not solidify, and then the energy beam having an energy level higher than the energy level during the film formation process is irradiated to the impurities. Preferably.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The vapor deposition material used in the present invention may be any material as long as it can be melted and vaporized by irradiation with an energy beam, for example, Ag, Al, Cu, Au, Pt, P.
It is possible to use metals such as d, Pb, Ni, Ti, In and the like. As the energy beam source used for melting the vapor deposition material, removing impurities from the melt, and vaporizing the vapor deposition material, in addition to the electron beam generation source, an excimer laser,
It is possible to use a high power laser such as a YAG laser or a CO ₂ laser. The output of the energy beam irradiated when the vapor deposition material is melted, when impurities are removed, and when the vapor deposition material is vaporized is different if the vapor deposition material and the material of the crucible are different, but it is possible to implement the present invention even if the output is different due to these differences. is there.

Among the methods of forming a thin film while removing impurities of the present invention, a basic continuous vapor deposition method will be described below with reference to the drawings, but the present invention is limited to the following examples. Not done. The vapor deposition material had a purity of 9 in all the examples.
9.99% Ag was used. The energy beam used was an electron beam in all the examples.

Embodiment 1 FIG. 1 shows an electron beam output value and a shutter opening / closing timing in time series, FIG. 2 shows a vapor deposition material supply and impurity removing treatment step, and FIG. 3 shows a thin film forming treatment step. . In this embodiment, since the thin film forming process can be continuously performed,
As shown in FIGS. 2 and 3, a supply side reel 3 of a hoop base material 5 as a base material to be vapor-deposited, a take-up side reel 4 and a supply reel 6 of a vapor deposition material (Ag wire) 7 are provided in a vacuum chamber 1. ing.

[Supply / Melting of Vapor Deposition Material and Impurity Removal Processing] During supply / melting of the vapor deposition material and impurity removal processing, the shutter 16 is closed and feeding of the hoop base material 5 is stopped. As shown in FIG. 2, the vacuum chamber 1
The vapor deposition material 7 was sent from the supply reel 6 into the crucible 8a. A direct current electron beam 10 having an acceleration voltage of 10 kV and an emission current of 60 mA emitted from an electron gun 9 is bent by a beam direction changing magnet 12 and irradiated with the vapor deposition material 7 sent into the crucible 8a to melt the vapor deposition material 7, A melt 13 was obtained. As you can see in the figure,
The crucible 8a is supported by a holder 11a, and the magnet 12 is built in the holder 11a. The output value of the electron beam 10 when the vapor deposition material is melted is shown in FIG.
As shown in (4), the output value was the same as the output value when the Ag film was formed on the substrate 5 (during film formation).

When the vapor deposition material 7 is made into the molten liquid 13, the impurities contained in the vapor deposition material 7 float on the liquid surface of the molten liquid 13 as the floating impurities 14a. As shown in FIG. 1, with respect to the above floating impurities 14a, an acceleration voltage of 10 kV, which is as high as 10 times the output when the vapor deposition material is melted,
The direct current electron beam 10 having an emission current of 600 mA was irradiated. Then, the floating impurities 14 a were evaporated and scattered and removed from the liquid surface of the melt 13. At this time, most of the evaporated impurities 14b were scattered toward the shutter 16 which was closed in advance.

[Film Forming Treatment] After the above-mentioned impurity removing treatment, as shown in FIG. 3, the supply of the vapor deposition material 7 to the crucible 8a is stopped, the shutter 16 is opened, and the hoop base material 5 is fed, while the crucible 8a is being fed. As shown in FIG. 1, on the clean liquid surface of the molten liquid 13 in which the floating impurities 14a do not exist, the acceleration voltage 10 which is a low output reduced to 1/10 of the output at the time of impurity removal.
DC electron beam 10 with kV and emission current 60mA
When the molten liquid 13 was evaporated by irradiating with, the evaporation particles 15 of the vapor deposition material were vapor-deposited on the surface (lower surface) of the base material 5, and a thin film was formed on the surface of the base material 5.

[Continuously repeating a series of treatments] When the amount of the melt 13 in the crucible 8a becomes small due to the above thin film formation, the feeding of the hoop base material 5 is stopped again, the shutter 16 is closed, and the above-mentioned process is performed. The vapor deposition material 7 was supplied / melted and impurities were removed, and then the thin film forming process was performed again. In this way, from the supply and melting of the vapor deposition material to the thin film formation processing through the impurity removal processing, as shown in FIG.

[Results] As a result of carrying out as described above, film defects are not caused due to the inclusion of impurities in the base material caused by the impurities floating on the liquid surface of the melt and the adhesion of melt droplets. Was able to be significantly reduced. It was also possible to realize continuous vapor deposition. Moreover, these could be done with a single energy beam source.

Example 2 In this example, impurities floating on the liquid surface of the molten material were collected in one place so that the impurities could be efficiently removed. As shown in FIG. 4, while the blade 81 is provided on the bottom of the crucible 8a,
The crucible 8a was installed in a holder 11b having a vertical support shaft 17 on its bottom surface, and the motor 18 was used to rotate the support shaft 17. In this case, attach the crucible 8a to the holder 1
It was installed eccentric to 1b. Therefore, the crucible 8a rotates horizontally with the eccentric position inside the crucible 8a as the center of rotation.

In the figure, the parts having the same numbers as those used in the first embodiment indicate the same components. Other configurations are shown in FIGS.
Since it is the same as, the description is omitted. When the crucible 8a was rotated, the blade 81 stirred the melt 13 in the crucible 8a, so that the impurities in the melt 13 floated on the liquid surface of the melt 13 easily and quickly. Impurities 14 floating / floating on the liquid surface
Since a is gathered in the vicinity of the center of rotation by the eccentric rotation of the crucible 8a, the concentrated floating impurities 14a are intensively irradiated with a high-power electron beam, so
a was effectively removed.

The supply / melting of the vapor deposition material and the thin film forming treatment were performed in the same manner as in Example 1, and the point similar to that of Example 1 was that the supply of the vapor deposition material to the thin film forming treatment were continuously repeated. In this example, the impurities were easily and quickly concentrated at one location on the liquid surface of the molten material, so that the impurity removal treatment time could be shortened as compared with Example 1.

-Embodiment 3 In this embodiment, as in the case of Embodiment 2, impurities floating on the liquid surface of the molten material are collected in one place so that the impurities can be efficiently removed. As shown in FIG. 5, the vibrators 19 and 19 were installed on the two opposite side surfaces of the holder 11a supporting the crucible 8a. By the excitation of the oscillator 19, the impurities in the melt 13 are collected as floating impurities 14a in one place on the liquid surface of the melt 13, and the concentrated floating impurities 14a are irradiated with a high-power electron beam 10. This floating impurity 14a
Was removed.

In this embodiment, the molten liquid 13 forms a wave front by applying the above-mentioned vibration, and the floating impurities 1 ride on the wave.
4a is concentrated near the center of the crucible 8a. The supply / melting of the vapor deposition material and the thin film forming treatment were performed in the same manner as in Example 1, and the point that the supply of the vapor deposition material and the thin film forming treatment were continuously repeated was also performed in the same manner as in Example 1.

As a result of carrying out as described above, the impurity removing treatment time can be shortened as compared with the first embodiment. Further, as compared with Example 2, the impurities could be concentrated on one place of the liquid surface by a simple mechanism of vibrating by the vibrator. -Example 4- In this example, the crucible has a vapor deposition material supply side and an evaporation side.

As shown in FIG. 6, the crucible 8a having a single tank structure.
A partition plate 82a having the same height as the height of the crucible in the center of the
The inside of the tank was divided into a vapor deposition material supply side 83a and a vapor deposition material vaporization side 83b by providing the head so as to be slightly above the liquid surface. Below the partition plate 82a is the crucible 8a.
There is a gap 82b with the bottom of the
The melt 13 obtained in 3a can be transferred to the evaporation side 83b of the vapor deposition material through this gap 82b.

Irradiation with an energy beam (not shown) was alternately applied to the vapor deposition material supply side 83a and vaporization side 83b. In order to prevent the temperature of the melt on the side not hit by the energy beam from decreasing, the crucible holder 11a
The heater 20 is provided on the inside of the crucible 8b so as to surround the melt 1.
3 was kept warm.

Further, the melt 13 on the supply side 83a
In order to collect the floating impurities 14a on the liquid surface in one place, a vibrator 19 is provided on one side surface of the crucible holder 11a. In the figure,
Portions with the same numbers as in Example 1 represent the same components. The other structure is similar to that of FIGS. In this embodiment, the partition plate 82a could prevent the impurities 14a floating on the liquid surface of the vapor deposition material supply side 83a from flowing into the vapor deposition material vaporization side 83b. Further, the melt 13 near the bottom of the vapor deposition material supply side 83a moves to the vapor deposition material evaporation side 83b through the gap 82b, but the melt near the bottom has extremely less impurities than the melt near the liquid surface. Therefore, it was possible to supply the melt 13 containing less impurities to the vapor deposition material evaporation side 83b than in the first to third embodiments.

Similar to the first embodiment, the process from the supply / melting of the vapor deposition material to the thin film forming process is continuously repeated. Impurities are constantly generated during melting of the vapor deposition material 7, but the floating impurities 14a existing on the liquid surface of the vapor deposition material supply side 83a are transferred to the vapor deposition material evaporation side 83b.
Since it can be blocked by a, the evaporation material evaporation side 83
It was possible to continue evaporation at b. Therefore, one film forming treatment time was long.

As a result of carrying out as described above, Examples 1 to 3
Compared with the above, the number of impurity removal treatments could be reduced, the thin film formation treatment could be performed for a long time, and a cleaner thin film could be formed. Example 5 In this example as well, the crucible has a vapor deposition material supply side and an evaporation side.

In this embodiment, a crucible having two tanks was used, one tank serving as the vapor deposition material supply side and the other tank serving as the vapor deposition material evaporation side. As shown in FIG. 7, the crucible 8b has two tanks, that is, a vapor deposition material supply side 83a and a vapor deposition material evaporation side 83b. The bottoms of the crucible 8b are connected by a pipe 83c, and the molten material is provided at the center of the pipe 83c. A valve 21 was provided to allow the supply amount of 13 to be adjusted.

In the figure, the parts with the same numbers as in the first embodiment represent the same components. The other structure is similar to that of FIGS. Although not particularly limited, when the valve 21 is opened, the vapor deposition material melting side 8 is opened.
It is preferable to temporarily stop the supply of the vapor deposition material 7 to 3a. Similar to the first embodiment, the process from the supply / melting of the vapor deposition material to the thin film forming process is continuously repeated.

The difference between this embodiment and Embodiments 1 to 4 is that
Until the impurities contained in the melt 13 on the vapor deposition material supply side 83a that have not been floated are completely floated on the liquid surface, and then the impurities 14a floating on the liquid surface are irradiated with the electron beam 10 to be removed. Keep valve 21 closed,
The point is that the melt 21 can be supplied from the vapor deposition material supply side 83a to the vapor deposition material vaporization side 83b by opening the valve 21 after removing the floating impurities 14a.

Since the molten liquid after the floating of the impurities was sufficiently completed on the vapor deposition material supply side 83a was supplied to the vapor deposition material evaporation side 83b, a cleaner thin film than in Example 4 could be formed. -Example 6- In this example, since the floating impurities and the molten liquid are evaporated at the same time by the high-power electron beam irradiation during the impurity removal processing,
The method for removing impurities was improved so that evaporation of the melt could be suppressed.

FIG. 8 shows the output value of the electron beam and the shutter opening / closing timing in time series in this embodiment. Also in this embodiment, during the impurity removal process,
Similar to Example 1 and the like, the shutter is closed and the feeding of the hoop base material is stopped to melt the vapor deposition material and impurities are removed from the liquid surface of the melt, and the shutter is opened to feed the hoop base material from the melt. Although the vapor deposition material is evaporated to form a film, unlike Example 1 or the like, as shown in the figure, after the vapor deposition material is melted and before the impurity removal processing, the electron beam irradiation is temporarily stopped (energy level Is zero), and after cooling the melt to such an extent that it does not solidify, a high-power (acceleration voltage 100 kV, emission current 1 A) pulsed electron beam (pulse width 5) is applied to the impurities floating on the surface of the melt.
ns, a repetition frequency of 1 kHz) was applied to remove floating impurities.

Supplying and melting of vapor deposition materials and thin film formation processing are
It is also similar to Example 1 in that the same process as in Example 1 is performed, and the process from the supply of the vapor deposition material to the thin film forming process is continuously repeated. As a result of carrying out as described above, unlike Example 1, the electron beam used at the time of removing impurities was not a DC continuous wave but a pulse shape, and the molten liquid was once cooled before the impurity removing process. Example 1
It was possible to suppress the evaporation of the melt during the impurity removal process.
As a result, the waste of the evaporation material can be reduced.

[0036]

The thin film forming method by energy beam heating vacuum evaporation according to the present invention has the following effects because it is configured as described above. Claim 1
In the invention described in (1), since a single energy beam source is used for both the thin film forming process and the impurity removing process, and an impurity removing device other than the single energy beam source is not required, the equipment cost can be reduced as compared with the conventional case.

In the invention described in claim 2, the above-mentioned claim 1
In addition to the effects of the invention described in 1), since the impurity removal process and the film formation process can be continuously performed within one badge by adjusting the energy power, the film formation is simpler, faster, and in a larger amount than before. it can. In the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2,
The impurities can be efficiently removed by collecting the impurities at a specific position on the surface of the melt.

In the invention described in claim 4, the above-mentioned claim 3
In addition to the effects of the invention described in (1), by rotating the crucible, impurities can be driven to the center or edge of the liquid surface of the melt by centrifugal force, and the impurities can be removed efficiently by irradiating with a high energy beam there. It can be carried out. In the invention described in claim 5, in addition to the effect of the invention described in claim 4, by eccentrically rotating the crucible, stirring of the melt in the crucible is promoted, and impurities in the melt are easily dissolved. The impurities can be efficiently removed by irradiating the surface with a high energy beam.

In the invention according to claim 6, the above-mentioned claim 3
In addition to the effect of the invention described in (1), by installing ultrasonic transducers on two opposing side surfaces of the crucible holder, impurities can be collected in one place near the center of the liquid surface of the melt, which is efficient. Can remove impurities. According to the invention of claim 7, in addition to the effect of the invention of claim 6,
Compared to the crucible rotating structure, the floating impurities can be collected in one place with a simple structure.

In the invention described in claim 8, the above-mentioned claim 3 is used.
In addition to the effect of the invention described in any one of 1 to 7, since the crucible has the melt stirring means, the stirring efficiency is further improved, and thus the impurity removal treatment efficiency is further improved.
In the invention described in claim 9, in addition to the effect of the invention described in claim 1 or 2, since the crucible is separated into a vapor deposition material supply side and an evaporation side, floating of impurities generated on the supply side is prevented. Since it is less likely to occur on the evaporation side, it is possible to significantly reduce the mixing of impurities into the thin film and the adhesion of droplets of the molten liquid to the substrate, and it is possible to form a cleaner thin film.

According to the invention of claim 10, in addition to the effect of the invention of claim 9, since the crucible has a structure capable of heating itself, the crucible is cooled and the molten liquid during film formation is cooled. Can be prevented from solidifying. According to the invention described in claim 11, in addition to the effect of the invention described in claim 9 or 10, the inside of the single crucible tank is divided into a supply side and an evaporation side of the vapor deposition material, so that the structure is simple. Thus, the effect of the invention described in claim 4 can be obtained.

According to the twelfth aspect of the invention, in addition to the effect of the ninth or tenth aspect of the invention, the vapor deposition material supply side tank and the evaporation side tank are connected by a pipe. As compared with the case of the invention described in claim 11, mixing of impurities into the tank on the evaporation side and floating of the liquid surface are reduced. In the invention described in claim 13, in addition to the effect of the invention described in claim 12, since the pipe has means for adjusting the supply amount of the molten liquid to the evaporation side, impurities on the supply side are removed. Since the molten liquid can be supplied to the vapor deposition side after the removal, a film having a higher purity can be formed.

According to a fourteenth aspect of the invention, in addition to the effect of the invention according to any one of the first to thirteenth aspects, an energy beam of a high energy level with a magnification of a predetermined width of the energy level at the time of film formation is obtained. By the irradiation of, the efficiency of removing the impurities floating on the melt surface is further enhanced. In the invention described in claim 15, in addition to the effect of the invention described in any one of claims 1 to 14, the irradiation energy beam during the impurity removal treatment is pulsed, so that the melting during the impurity removal treatment is performed. The evaporation of the liquid can be suppressed, and the waste of the evaporation material can be reduced.

According to the sixteenth aspect of the invention, in addition to the effect of the invention according to any of the first to fifteenth aspects, the irradiation of the energy beam is temporarily stopped before the impurity removal treatment so that the molten liquid is not solidified. By cooling to a certain degree, without providing a mechanism for pulsing the energy beam,
It is possible to suppress the evaporation amount of the molten liquid during the impurity removal processing.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an output value of an electron beam and a shutter opening / closing timing in time series in an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a vapor deposition material supply / melting process and a floating impurity removal treatment process in the above embodiment.

FIG. 3 is a cross-sectional view showing a vapor deposition material evaporation step in the above embodiment.

FIG. 4 is a cross-sectional view showing a floating impurity removing process step according to the second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a floating impurity removal processing step according to the third embodiment of the present invention.

FIG. 6 is a sectional view showing a floating impurity removing process step in a fourth example of the present invention.

FIG. 7 is a cross-sectional view showing a floating impurity removing process step in a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing the output value of an electron beam and the shutter opening / closing timing in time series in the sixth embodiment of the present invention.

[Explanation of symbols]

 1 vacuum chamber 5 hoop base material 7 vapor deposition material 8a crucible with one tank 8b crucible with two tanks 10 electron beam 11a non-rotating crucible holder 11b rotating crucible holder 13 melt 14a impurities floating on the surface of the melt 15 Evaporated particles of vapor deposition material 19 Oscillator 20 Heater 21 Valve

Claims (16)

[Claims] 1. A method of forming a thin film on the surface of a substrate by heating the vapor-depositing material to melt and evaporate it by irradiating the vapor-depositing material in a crucible with an energy beam under vacuum, The energy beam emitted from a single energy beam source when it is necessary to remove impurities floating on the liquid surface of the melt in the crucible in an appropriate process from melting of the vapor deposition material to film formation. A method for forming a thin film by energy beam heating vacuum deposition, wherein the impurities are removed by irradiating the impurities with an energy level higher than that during film formation. 2. The thin film forming method according to claim 1, wherein continuous vapor deposition is performed by alternately repeating high energy level impurity removal processing and low energy level film formation processing. 3. The method for forming a thin film according to claim 1, wherein impurities floating on the liquid surface of the melt are collected and removed at a specific location on the liquid surface. 4. The method of forming a thin film according to claim 3, wherein the crucible has a structure that rotates in a horizontal plane. 5. The center of rotation is at an eccentric position in the crucible,
The thin film forming method according to claim 4. 6. The method of forming a thin film according to claim 3, wherein the crucible is vibrated so that impurities are collected at the specific place. 7. The thin film forming method according to claim 6, wherein vibration is applied from one side of the crucible to collect impurities near the opposite side. 8. The method for forming a thin film according to claim 3, wherein the crucible has means for stirring the molten liquid. 9. The crucible has a structure in which a vapor deposition material supply side and a vaporization side are separated from each other, and impurities generated during melting of the vapor deposition material are prevented from flowing out to the vaporization side. And irradiating the energy beam emitted from a single energy beam source to the supply side and the evaporation side while changing the energy level of the energy beam.
Alternatively, the thin film forming method described in 2. 10. The method for forming a thin film according to claim 9, wherein the crucible has a structure capable of heating itself. 11. The thin film forming method according to claim 9, wherein the crucible has a single tank structure, and the inside of the tank is divided by a partition into the supply side and the evaporation side. 12. The crucible has a tank serving as the supply side and a tank serving as the evaporation side, and these two tanks form a molten liquid obtained by melting a vapor deposition material on the supply side on the evaporation side. 9. Pipe connection for feeding to
0. The thin film forming method described in 0. 13. The method for forming a thin film according to claim 12, wherein the tube has a means for adjusting a supply amount of the molten liquid to the evaporation side. 14. The energy level at the time of the impurity removal treatment is twice to 10 times the energy level at the time of the film formation treatment.
The thin film forming method according to any one of claims 1 to 13, wherein the film thickness is 00 times. 15. The method of forming a thin film according to claim 1, wherein the energy beam irradiated during the impurity removal process is pulsed. 16. Before the impurity removing process, once the irradiation of the energy beam is stopped and the melt is cooled to such an extent that it does not solidify, the energy beam having an energy level higher than the energy level during the film forming process is used as the impurity. The method for forming a thin film according to claim 1, wherein irradiation is performed.