JP2014034698A - Film deposition method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deposit a thin film of ceramic etc., directly on a substrate of an organic semiconductor or of a resin material which is weak to heat and damage, at high speed with small damage.SOLUTION: A substrate 6 is arranged above a film deposition material 5 at a lower part 31a in a vacuum vessel 21, and the film deposition material is heated by being supplied with an electron beam 30 from a position in a vacuum vessel sideward part 31b and above the height of the film deposition material, thereby evaporated and sublimated, and the evaporated and sublimated evaporation and sublimation substance is deposited on the substrate. A plasma region 37 that is formed by the electron beam 30 and is positioned above the film deposition material 5 is set to be below the horizontal height of the electron beam to thereby make small a section where the evaporated and sublimated evaporation and sublimation substances pass through the plasma region, and the evaporation and sublimation substances are deposited on the substrate in a small-ionization-rate state. The sublimation substance is made larger in amount than the evaporation substance. A sublimation temperature is lowered by controlling partial pressure in the vacuum vessel to increase a sublimation amount. A height H of the electron beam from an evaporation surface of the film deposition material is equal to or larger than the diameter 4D of the electron beam.

Description

  The present invention relates to a film forming method and apparatus for forming a metal or ceramic thin film on a substrate using an electron beam, and particularly suitable for forming a substrate that is vulnerable to heat damage such as an organic semiconductor or a resin material. The present invention relates to a membrane method and apparatus.

  Conventionally, organic semiconductors are used in organic EL and organic photovoltaic power generation devices, but organic materials are easily damaged by sputtered particles, charged particles, and electromagnetic waves in addition to low heat resistance. The current situation is that the inherent properties cannot be fully exhibited.

  Known film forming methods on the substrate include sputtering, electron beam heating vacuum deposition, and ion plating. In the sputtering method, for example, in Patent Document 1, a film forming material is disposed opposite to each other, and sputtering is performed by applying electron energy to the film forming material, and sputtered particles are attached to the substrate from the film forming material. . However, since the sputtered particles are activated, they have high thermal energy, and the substrate temperature rises to 70 to 75 ° C., which is not suitable for film formation on an organic EL or the like, and the film formation speed. There was also the problem of being slow.

  Further, in the electron beam heating vacuum deposition method as described in the cited document 2, the film forming material is irradiated with an electron beam from an electron beam irradiator disposed near the film forming material, and the film forming material is heated and evaporated to form a substrate. Form a film. Since this film irradiates a film forming material with an electron beam at a high speed, for example, 1000 eV or more, X-rays and ultraviolet rays are always generated. These X-rays and ultraviolet rays damage organic semiconductors. For this reason, it is necessary to arrange a shield between the substrate and the film forming material. However, the indirect vapor deposition method through such a shield has a complicated structure and a small film formation area. In addition, since it is unavoidable to mix the material constituting the shield, it is difficult to form a high-purity film of a high melting point material such as an oxide or a nitride.

  On the other hand, in the ion plating method, for example, in Patent Document 3, as shown in FIG. 2 (inverted left and right), the film forming material 5 is provided in the lower part 21a in the vacuum vessel 21, and the upper part 21c faces the film forming material. A substrate 6 is arranged, an electron beam 40 is supplied from a position 31 higher than the vacuum vessel side 21b and higher than the height of the film forming material toward the film forming material 5 to generate a plasma 41, the film forming material is heated, evaporated and Sublimate. The energy at this time is electron beam irradiation heating with a relatively low energy of about 10 to 100 eV, and only the surface of the film forming material can be locally heated, evaporated and sublimated. Further, the sublimation particles are ionized by the electron beam plasma 41 above the film forming material and incident on the substrate 6 in a highly active state to form an oxide such as SiOxNy. In Patent Document 4, ionized particles are incident on a glass substrate and reacted with oxygen gas to form a thin film such as ZnO.

Japanese Patent No. 4473852 JP 2010-132991 A JP 2008-297587 A JP 2009-197333 A

  However, as described above, the sputtering method raises the temperature so that it cannot be formed on the organic EL or the like. Further, in the electron beam heating vacuum deposition method, the structure is complicated in order to reduce damage, and mass production is difficult. Furthermore, in the ion plating method, it is disclosed that a film of ZnO is formed on a glass substrate. However, ions ionized by plasma have a potential energy of +30 to +60 V, and heat energy is applied to the substrate. For this reason, there is a problem that the substrate made of an organic semiconductor or a resin material is damaged.

  SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to form a thin film such as a ceramic directly on a substrate made of an organic semiconductor or a resin material that is vulnerable to heat and damage, and to form a thin film such as a ceramic film at a high speed with low damage. Is to provide a device.

  As a result of studying the point of reducing the temperature influence on the substrate in the ion plating methods as described in Patent Documents 3 and 4, the present inventors have damaged the substrate by ionization energy when the evaporation / sublimation material is ionized. It has been found that the influence is large, and that the deposition performance is better as the sublimation material is increased in the evaporation / deposition material instead of the ionization.

Based on this knowledge, in the present invention, a film forming material is provided in the lower part of the vacuum container, and a substrate is disposed in the upper part of the vacuum container so as to face the film forming material. An electron beam is supplied from a position higher than the height toward the film forming material, the film forming material is heated, evaporated and sublimated, and the evaporated and sublimated evaporated / sublimated material is attached to the substrate to obtain a thin film. A membrane method,
The plasma region formed by the electron beam above the film forming material is set to be lower than the horizontal height of the electron beam, so that the vaporized and sublimated evaporated / sublimated substance passes through the plasma region. In addition, the above-described problems have been solved by providing a film forming method for forming a film on the substrate with an evaporation / sublimation material having a low ionization rate.

  That is, in the present invention, the film forming material is uniformly irradiated, evaporated and sublimated so that the plasma region formed by the electron beam is lower than the horizontal height of the electron beam. On the other hand, the number of sections through which the evaporating / sublimating material passes through the plasma region is reduced, the increase in energy by ionization is suppressed, and the film is formed with the evaporating / sublimating material having a low ionization rate. The electron beam acceleration voltage is set to 100 eV or less, the electron beam incident depth of the metal / ceramic film forming material is set to several nm or less, and most of the electron beam energy is converted into thermal vibration to locally heat the film forming material. To do. By this heating, the high melting point material can be evaporated and sublimated with a small amount of electric power, and the evaporated / sublimated substance is deposited on the substrate with the composition and structure close to the film forming material. For this reason, the recrystallization energy of the evaporation / sublimation substance on the substrate can be reduced, and the heating of the substrate can also be reduced.

  In brief, in the electron beam heating vacuum deposition method, an electron beam irradiator is placed near the film forming material in order to efficiently evaporate the film forming material, and an electron beam of 1000 eV or more is concentrated on the film forming material. Melted and evaporated. Further, the evaporated substance does not pass through the plasma region. Conversely, in the ion plating method, an electron beam is emitted from a position higher than the side higher than the film forming material to generate plasma by the electron beam, and the film forming material is evaporated with low energy of about 10 to 100 eV by the plasma. Sublimation is performed, and further, evaporation and sublimation substances are ionized and activated by passing through a plasma generated by an electron beam. The present invention can be said to be intermediate between a low-energy melting method using ion plating plasma and a deposition method using no electron beam heating vacuum deposition method.

  In the invention described in claim 2, the evaporation / sublimation substance has a film forming method in which the sublimation substance is larger than the evaporation substance. Increasing the amount of sublimation substance makes it easier to adhere to the substrate and also increases the adhesion performance to the substrate. In some cases, there is no sublimation substance.

  In the invention according to claim 3, the partial pressure in the vacuum vessel is controlled to lower the sublimation temperature and increase the sublimation amount. As shown in FIG. 6 of Patent Document 3, when the substance is vaporized, in the relationship between the partial pressure and the melting temperature, the lower the partial pressure with respect to the melting temperature, the easier the sublimation occurs. The sublimation amount is increased by controlling the melting temperature and partial pressure for the film forming material. This value varies depending on the film forming material including the case where no sublimation is performed.

Furthermore, in the invention described in claim 4, a film forming material disposed in a hearth provided in the lower part of the vacuum container, a substrate disposed in the upper part of the vacuum container facing the hearth, and the vacuum An arc gun for supplying an electron beam from a position on the side of the container and higher than the Hearth height toward the film forming material in the vacuum container to melt, evaporate and sublimate the film forming material, and the evaporation and sublimation A film forming apparatus for obtaining a thin film by attaching the evaporated / sublimated substance to the substrate,
A sub electromagnet for converging the flow of the electron beam tip toward the film forming material side is provided, and the height of the electron beam from the evaporation surface of the film forming material is combined with the converging force with the sub electromagnet to form the component. The plasma region formed by the electron beam above the film material is set to a position below the horizontal height of the electron arc gun, and the evaporation / sublimation material passes through the plasma region formed by the electron beam. There is provided a film forming apparatus in which the number of sections is reduced and a film can be formed on the substrate with an evaporation / sublimation material having a low ionization rate in the plasma region.

  That is, the height of the electron beam is set so that the plasma region is positioned below the horizontal height of the arc gun (electron gun). In addition, by arranging a sub electromagnet, the diffusion of the electron beam is reduced, the plasma area is reduced, the section through which the evaporation / sublimation substance passes through the plasma area is reduced, and the evaporation / sublimation substance with a low ionization rate is formed on the substrate. I was able to do it. Although the arc gun is generally arranged in the horizontal direction, by arranging it so that it can irradiate obliquely downward, the bending of the electron beam is reduced, the melting efficiency is increased, and the plasma region on the film forming material is increased. Can be small.

  In the invention according to claim 5, the height H of the electron beam from the evaporation surface of the film forming material is the diameter of the electron beam between the position of the film forming material evaporation surface of the electron beam and +20 mm. Is a film forming apparatus in which D is set to φD and D ≦ H ≦ 4D. If the height is smaller than the diameter of the electron beam, the arc easily interferes with the apparatus wall, the plasma cross section becomes flat, and evaporation / sublimation of the evaporation material becomes uneven. If it is higher than 4 times, the plasma region becomes too large. More preferably, 2D ≦ H ≦ 3D.

  According to a sixth aspect of the present invention, the electromagnet is a cylindrical air-core coil that is vertically long in the longitudinal direction, and is a film forming apparatus disposed on the outer periphery of the hearth. By making the coil long in the longitudinal direction, the plasma region can be narrowed.

  In the present invention, the evaporation / sublimation material passes through the plasma region to reduce the section, and the ionization rate is low, that is, the film is formed by the low energy evaporation / sublimation material. A thin film of ceramic or the like can be formed directly on a resin substrate with low damage. Further, since it is a kind of ion plating method, the film forming speed is high and the film forming area is wide and suitable for mass production. In addition, since the heating of the substrate can be reduced, it is possible to form a film directly on the organic semiconductor.

  In the invention described in claim 2, since the sublimation substance is larger than the evaporation substance and the adhesion to the substrate and the adhesion performance are increased, the film formation performance is good in addition to the low damage. In the invention described in claim 3, since the partial pressure in the vacuum vessel can be controlled to decrease the sublimation temperature and increase the sublimation amount, it is possible to form a film with better performance.

  Furthermore, in the invention described in claim 4, the height of the electron beam is set to a position where the plasma region is lower than the horizontal height of the arc gun, and the secondary electromagnet is disposed to reduce the plasma region, so that the ionization rate is low. Since the evaporation / sublimation material can be formed on the substrate, a film forming apparatus capable of forming a thin film such as ceramic directly on the substrate which is vulnerable to heat and damage with low damage is provided.

  In the invention described in claim 5, a film forming apparatus in which the height of the electron beam is not less than the diameter of the electron beam and not more than 4 times the diameter may be used. Further, in the invention described in claim 6, since the plasma region can be narrowed by arranging a vertically long cylindrical air-core coil on the outer periphery of the hearth, the structure of the conventional apparatus can be reduced without greatly changing the structure of the apparatus. It can be easily manufactured with an improved degree. In addition, the handling is similar to the conventional one, and it is easy to test the film forming conditions and set the mass production.

It is a schematic cross section of the film-forming apparatus in embodiment of this invention. It is a schematic cross section of a conventional ion plating apparatus (film forming apparatus).

  Embodiments of the present invention will be described with reference to the drawings. In addition, about the structure similar to what is shown in the conventional FIG. 2, the same code | symbol is attached | subjected mutually and description is abbreviate | omitted. In FIG. 1, a film forming apparatus 20 shown in the embodiment of the present invention includes a vacuum vessel 21, a hearth 22 on which a film forming material 5 provided on a lower portion 21a of the vacuum vessel is placed, and a side surface 21b of the vacuum vessel. An arc gun 23 for emitting an electron beam provided on the substrate 6 and a substrate holder 24 disposed on the upper portion 21c in the vacuum vessel facing the hearth are provided. The vacuum vessel 21 is provided with a reaction gas inlet 8 for supplying a reaction gas and the like and a vacuum exhaust device 11 for exhausting the gas in the vacuum vessel. The gas partial pressure and the degree of vacuum in the vacuum vessel 21 are adjusted by the reaction gas adjusting device 45 and the vacuum exhaust device 11 as shown in FIG.

  In the arc gun 23, the cathode 1 is provided at one end, and the hearth 22 is connected to the anode. The arc gun is provided with a doughnut-shaped electromagnet 25 and a permanent magnet 26 through a cylindrical insulating glass 9 so that an electron beam 30 enters the vacuum vessel. A rare gas inlet 7 for introducing an inert gas such as argon is provided in the arc gun 23. Around the hearth 22, an electromagnet 27, a permanent magnet 28, a cooling device 29 and the like for guiding the electron beam 30 are provided. The electron beam 30 generated from the arc gun 23 is guided to the cathode side hearth 22 to generate an arc discharge on the surface of the film forming material 5 on the hearth to locally heat the film forming material, thereby evaporating the film forming material. Sublimate. This is the same configuration as in the prior art, and a detailed description is omitted.

  In particular, in the present embodiment, the horizontal height H from the evaporation surface 5a of the film forming material of the arc gun 23 is set lower than the conventional one. This height H is set to be not less than D and not more than 4D with respect to the diameter φD of the electron beam at the film formation material evaporation surface to +20 mm. A sub electromagnet 32 made of a cylindrical air core coil that is vertically long in the longitudinal direction is provided at the electron beam emission outlet of the arc gun 23. By the sub electromagnet 32, the magnetic flux lines are pushed forward while being converged, and the magnetic field on the extension of the center line of the sub electromagnet is strengthened. Since the electron beam 30 is along the direction of the magnetic flux lines, the sub-electromagnet 32 makes the electron beam thinner. Further, a hearth side sub-electromagnet 33 made of a cylindrical air core coil that is vertically long in the longitudinal direction is provided on the outer periphery of the hearth 22 so that the electron beam 30 can be converged on the film-forming evaporation surface 5a.

  Thereby, the electron beam 30 forms a downward arc from the arc gun 23 toward the film forming material 5. As the distance from the arc gun increases, the diameter of the electron beam gradually increases, and the plasma region 31 reaches the upper part 5a of the film-forming material while drawing an arc without passing through the vicinity of the upper H position 34 of the film-forming material. The maximum value is obtained in the vicinity of the surface 36, and the evaporation surface 5a converges to the size of the film formation material evaporation surface.

  On the other hand, in the conventional film forming apparatuses of Patent Documents 3 and 4, as shown in FIG. 2, the height in the horizontal direction from the evaporation surface 5a of the film forming material of the arc gun 23 is not particularly disclosed. The sub electromagnet 42 has a donut shape in which the radial direction is larger than the longitudinal direction, and the magnetic flux density is increased. Then, the electron beam 40 travels in a substantially straight line from the arc gun 23 toward the film forming material 5, and goes downward at a position 44 directly above the film forming material. As the distance from the arc gun 23 increases, the diameter of the electron beam gradually increases, and the electron beam range is maximized at the upper portion 44 of the film forming material, thereby forming a greatly expanded plasma region 41. Further, the electron beam 40 reaches the film forming material evaporation surface 5a of the film forming material 5 while gradually converging downward. The sub-electromagnet 43 on the hearth side is also formed in a donut shape so as to spread the magnetic flux and make the electron beam 40 uniform on the evaporation surface of the film forming material.

  For this reason, in the prior art, the entire film forming material evaporation surface 5a is heated by the uniform beam 40, the film forming material 5 is evaporated and sublimated, and a plasma region 41 provided on the upper part of the film forming material is further formed. The vaporized / sublimated substance is made to pass through and is made to reach the substrate 6 in a high energy state.

  On the other hand, in the embodiment of the present invention, the plasma region 31 on the upper part of the film forming material is reduced, and the surface 5a of the film forming material 5 is locally heated to evaporate the high melting point material with less power. -It can be sublimated and the number of particles can be increased. Furthermore, the activation in the plasma region 31 can be reduced, and an evaporation / sublimation substance having the composition and structure of the film forming material can be deposited on the substrate. The deposited evaporation / sublimation substance is close to the composition and structure of the film-forming material, so recrystallization energy, for example, substrate heating, can be reduced compared to the prior art, enabling direct film formation on organic semiconductors. is there.

  The film forming apparatus is the same as the conventional ion plating apparatus in that the substrate is a cathode and the evaporation / sublimation substance from the film forming material as the anode moves to the substrate. Needless to say, various techniques can be applied, applied, and modified. Further, in the ceramic oxide film formation, the oxygen partial pressure to be reacted may be appropriately controlled in order to efficiently perform evaporation / sublimation and recrystallization.

DESCRIPTION OF SYMBOLS 5 Film-forming material 5a Evaporation surface 6 of film-forming material Substrate 20 Film-forming device 21 Vacuum container 21a Vacuum container lower part 21b Vacuum container side part 21c Vacuum container upper part 22 Hearth 23 Electron arc gun 30 Electron beam 31 Plasma region 32 Sub-electromagnet D Electron beam Diameter H of the electron beam from the evaporation surface of the film forming material

Claims (6)

A film forming material is provided in the lower part of the vacuum container, and a substrate is disposed in the upper part of the vacuum container so as to face the film forming material, and the film forming material is placed on the side of the vacuum container and higher than the height of the film forming material. A film forming method for obtaining a thin film by supplying an electron beam toward the substrate, heating the film forming material, evaporating and sublimating, and attaching the evaporated and sublimated evaporation / sublimation substance to the substrate,
The plasma region formed by the electron beam above the film forming material is set to be lower than the horizontal height of the electron beam, so that the vaporized and sublimated evaporated / sublimated substance passes through the plasma region. A film forming method characterized in that a film is formed on the substrate with an evaporation / sublimation material having a low ionization rate.   2. The film forming method according to claim 1, wherein in the evaporating / sublimating substance, the sublimation substance is larger than the evaporating substance.   3. The film forming method according to claim 2, wherein the partial pressure in the vacuum vessel is controlled to lower the sublimation temperature and increase the sublimation amount. The film-forming material disposed in the hearth provided in the lower part of the vacuum container, the substrate disposed in the upper part of the vacuum container facing the hearth, the side of the vacuum container and the position higher than the height of the hearth An electron arc gun that supplies an electron beam toward the film-forming material in a vacuum vessel to melt, evaporate, and sublimate the film-forming material, and attach the evaporated and sublimated substance to the substrate. A film forming apparatus for obtaining a thin film,
A sub electromagnet for converging the flow of the electron beam tip toward the film forming material side is provided, and the height of the electron beam from the evaporation surface of the film forming material is combined with the converging force with the sub electromagnet to form the component. The plasma region formed by the electron beam above the film material is set to a position below the horizontal height of the electron arc gun, and the evaporation / sublimation material passes through the plasma region formed by the electron beam. A film forming apparatus characterized in that the number of sections is reduced and a film can be formed on the substrate with an evaporation / sublimation material having a low ionization rate in the plasma region.   The height H of the electron beam from the evaporation surface of the film forming material is a position of D ≦ H ≦ 4D, where φD is the diameter of the electron beam between the position of the film formation material evaporation surface of the electron beam and +20 mm. The film forming apparatus according to claim 4, wherein   6. The film forming apparatus according to claim 4, wherein the sub electromagnet is a cylindrical air-core coil that is vertically long in a longitudinal direction, and is disposed on an outer periphery of the hearth.

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