JP5171583B2 - Electron beam evaporation system - Google Patents

Description

  The present invention relates to a vapor deposition apparatus for forming a thin film by evaporating a vapor deposition material with an electron beam.

  The vapor deposition apparatus using an electron beam evaporates the material by irradiating and heating an electron beam accelerated at a predetermined acceleration voltage to a vapor deposition material in a crucible arranged in a vacuum vessel. The deposited material is adhered to a deposition target member disposed in the vacuum vessel, for example, the surface of a substrate to form a thin film.

By the way, X-rays are always generated when high-speed electrons collide with a vapor deposition material such as metal, but there is a problem that some substrates are adversely affected by the X-rays.
Therefore, in order to suppress the adverse effect on the vapor deposition material by X-rays, the method of controlling the acceleration voltage of the electron beam according to the vapor deposition material (Patent Document 1) and the heating of the vapor deposition material in the crucible by the electron beam are not opposed to the substrate. There is a method (Patent Document 2) in which deposition is performed on a substrate surface by preheating by moving the crucible to a position facing the substrate.
Japanese Patent Laid-Open No. 10-158638 JP 2007-138235 A

  However, according to the method of controlling the acceleration voltage of the electron beam according to the vapor deposition material, the control of the acceleration voltage becomes complicated, and heating takes time to reduce the acceleration voltage, and the vapor deposition rate is reduced. There is.

In addition, in the method of performing deposition on the substrate surface by preheating, the influence of the X-rays on the substrate can be suppressed, but in the deposition by preheating, there is still a problem that the deposition rate is lowered.
Therefore, an object of the present invention is to provide an electron beam vapor deposition apparatus that can avoid the adverse effects of X-rays without reducing the vapor deposition rate.

In order to solve the above problems, an electron beam vapor deposition apparatus according to claim 1 of the present invention irradiates a vapor deposition material in a crucible disposed in a vacuum vessel with an electron beam, and vaporizes the vaporized material by the electron beam irradiation. Is a vapor deposition apparatus for forming a thin film by adhering to a surface of a vapor deposition member disposed in the vacuum vessel,
An X-ray shield is disposed between the crucible and the member to be vapor-deposited so as to be rotatable around the horizontal axis, and has heating means for heating the X-ray shield.
In addition, when the X-ray shield is irradiated to the member to be vapor-deposited from the opening of the crucible, the projection portion of the X-ray shield by X-rays is at least larger than the thin film formation range of the member to be vapor-deposited. That's what it was.

An electron beam vapor deposition apparatus according to a second aspect uses a cylindrical body, a cylindrical body, a sphere, or a spherical shell as the X-ray shield in the vapor deposition apparatus according to the first aspect.
Furthermore, the electron beam vapor deposition apparatus according to claim 3 is formed on both sides of the rotation axis while forming a through-hole penetrating in the vertical direction in the X-ray shield in the vapor deposition apparatus according to claim 1 or 2. The through direction of each through hole is made different so that the projected areas of the one through hole and the other through hole do not overlap each other.

  According to the configuration of the electron beam evaporation apparatus, since the X-ray shield is disposed between the crucible and the member to be evaporated, X-rays generated in the crucible can be prevented from reaching the surface of the member to be evaporated. At the same time, the evaporated material blocked by the X-ray shield is evaporated again from the deposition member side by the rotation of the X-ray shield and the built-in heater, so that the deposition member is X-rayed without reducing the deposition rate. Can be protected from.

Hereinafter, an electron beam evaporation apparatus according to an embodiment of the present invention will be described with reference to the drawings.
This electron beam evaporation apparatus is used, for example, when manufacturing a display unit of a panel display using an organic EL material.

  As shown in FIGS. 1 and 2, the electron beam evaporation apparatus is connected to a vacuum pump (not shown) and maintained at a predetermined degree of vacuum, and is disposed in the vacuum container 1. A crucible 2 filled with a vapor deposition material such as an organic EL material, and an electron beam irradiator 3 for irradiating an electron beam EB to the vapor deposition material disposed in the vacuum vessel 1 and filled in the crucible 2. A substrate holder 4 that can hold a substrate K as a member to be deposited is provided above the crucible 2 in the vacuum vessel 1. The electron beam irradiator 3 includes an electron beam generator 3 a and a beam introduction path 3 b for guiding the electron beam EB generated by the electron beam generator 3 a into the crucible 2.

An X-ray shield 11 that shields X-rays R is disposed above the crucible 2 in the vacuum container 1, that is, between the crucible 2 and the substrate holder 4.
For example, a cylindrical body is used as the X-ray shield 11. Further, as the material, a material capable of shielding X-rays, for example, a material having a high atomic number such as tungsten is used. According to this material, when the X-ray has a low energy of 10 keV or less, a sufficient shielding effect can be obtained with a thickness of about several hundred μm. For example, a thin cylindrical shielding portion having a thickness of about 1 mm is formed into a columnar shape. What is necessary is just to affix on the surface of a main-body part. Although a modification of the X-ray shield will be described later, when a cylindrical body is used as the X-ray shield, a cylindrical body having a thickness of about 1 mm may be used.

  The X-ray shield 11 has support shafts 11a at both ends supported rotatably around a horizontal axis a via a bearing member 12 and a predetermined rotation by a rotation drive device (not shown). The X-ray shield 11 has a built-in heater 13 as a heating means, and the X-ray shield 11 is kept at a predetermined temperature, that is, above the melting point of the vapor deposition material. It can be heated to temperature. Of course, although not shown in the figure, the heater 13 is connected to electric wiring and provided with a temperature control unit.

  Further, as shown in FIG. 3, the X-ray shield 11 shields the X-ray by the X-ray R when the substrate K held by the substrate holder 4 is irradiated with the X-ray R from the opening 2 a of the crucible 2. The projection portion of the body 11 is preferably sized so as to substantially match the thin film formation range so that it is at least the thin film formation range of the substrate K.

  When it is necessary to avoid the thermal influence on the substrate K, the X-ray shield 11 (particularly, the surface facing the substrate K) has a minimum size (area) on the assumption that the thin film formation range is satisfied. It is desirable to make it.

  Further, the shape of the X-ray shield is preferably a cross-sectional shape similar to the shape of the substrate K (more precisely, in a horizontal cross-sectional shape or a projected shape), and when the shape of the substrate K is a rectangle, A cylindrical body (or prismatic body) is used as the X-ray shield. Therefore, as will be described later, if the substrate K is circular, a sphere is used.

  Here, the geometric dimension in the cross section of the X-ray shield 11 will be described. The ratio between the width W1 of the X-ray shield 11 and the thin film formation range (the width of the substrate in the drawing) W2 on the substrate K is as follows. The vertical distance H1 from the center C of the crucible 2 (or the surface of the vapor deposition material) to the center D of the X-ray shield 11 and the vertical distance H2 from the center C of the crucible 2 to the surface of the substrate K are equal to each other. Has been. That is, a relationship of W1 / W2 = H1 / H2 (similarity relationship) is established. Note that the axial direction of the X-ray shield 11, that is, the longitudinal direction has the same relationship as shown in FIG. 4. That is, the ratio between the length L1 of the X-ray shield 11 and the thin film formation range (the length of the substrate in the drawing) L2 on the substrate K is from the center C of the crucible 2 to the center D of the X-ray shield 11. It is set to be equal to the ratio of the vertical distance H1 and the vertical distance H2 from the center C of the crucible 2 to the surface of the substrate K (L1 / L2 = H1 / H2).

  Therefore, when forming a thin film of vapor deposition material on the surface of the substrate K, the substrate holder 4 is held by the substrate K, the crucible 2 is filled with the vapor deposition material, and then kept at a predetermined degree of vacuum by a vacuum pump. The X-ray shield 11 is rotated at a predetermined speed (relatively slowly), and the surface of the X-ray shield 11 is maintained at a temperature equal to or higher than the melting point of the vapor deposition material.

  Then, the electron beam irradiator 3 is operated to irradiate the crucible 2 with the electron beam EB to heat the vapor deposition material. When the vapor deposition material is heated to a melting temperature or higher, evaporation is performed, and a part of the vaporized vapor deposition material, that is, the evaporation material M rises through the periphery of the X-ray shield 11 and adheres to the surface of the substrate K. Of course, a part of the evaporating material M rises along the periphery of the X-ray shield 11, goes around the upper part, and adheres to the central portion of the substrate K.

  By the way, since the X-ray shield 11 is disposed above the crucible 2, most of the evaporation material M adheres to the surface of the X-ray shield 11. However, since the X-ray shield 11 is heated above the melting temperature and is rotated slowly, the evaporation material M adhering to the X-ray shield 11 is evaporated again while moving upward due to the rotation. , And adhere to the surface of the central portion of the substrate K. That is, even if the X-ray shield 11 is present, the evaporation onto the substrate K is sufficiently performed by the evaporation material M evaporated again from the X-ray shield 11.

  At this time, the X-ray R is generated by the electron beam irradiated to the vapor deposition material. However, since the X-ray shield 11 is disposed, the substrate K equal to the projected area (precisely, the thin film formation region) Is shielded from X-rays R.

  3 and 4 show the detected intensity distribution of X-rays at the substrate K position. As can be seen from these drawings, it can be seen that the X-ray intensity is significantly reduced in the projection portion by the X-ray shield 11. That is, it can be seen that the substrate K is shielded by the X-ray shield 11 and protected from X-rays.

  As described above, since the X-ray shield is disposed between the crucible and the substrate, the X-ray generated in the crucible can be prevented from reaching the substrate surface by the X-ray shield, Since the evaporated material blocked by the X-ray shield is evaporated again on the substrate side by the rotation of the X-ray shield and the built-in heater, the substrate is protected from X-rays without reducing the deposition rate. be able to.

  In particular, the X-ray can be suppressed by arranging the X-ray shield, and there are many advantages by using an electron beam. That is, the electron beam evaporation can cope with a material having a high melting point of a refractory metal or oxide, and has excellent thermal controllability compared to resistance heating. Further, since the vapor deposition material adhering to the shield is small and the heat capacity is small, the input power to the shield is small.

  In the above embodiment, the X-ray shield has been described as a cylindrical body. For example, as shown in FIGS. 5 and 6, a cylindrical shape, that is, a cylindrical body is used as the X-ray shield 21. A plurality of slits 22 along the axial direction may be formed at predetermined angles. However, these slits 22 are formed at three places, for example, every 120 degrees so as not to be aligned with each other. In other words, the crossing angle of each other is a value other than 90 degrees and 180 degrees. This is to prevent the X-ray R from passing through the X-ray shield 11.

  When the slit 22 is expressed in a general way (explaining the slits 22A and 22B in FIG. 5), slits (through holes) 22A and 22B penetrating in the vertical direction in the X-ray shield 21 are formed. The slits (through holes) are formed so that the projected areas of the slits (through holes) 22A on one side and the slits (through holes) 22B on the other side formed on both sides of the rotation axis do not overlap each other. The penetration directions of 22A and 22B are made different.

  As shown in FIG. 7, when the substrate has a circular shape, a spherical material, that is, a sphere, is used as the X-ray shield 31, and further, as shown in FIG. Alternatively, a spherical shell having a predetermined thickness, that is, a spherical shell may be used, and a plurality of slits 42 may be formed at predetermined angles. Of course, the slits 42 are not aligned with each other.

  Furthermore, in the above-described embodiment, the suppression of the influence of the X-rays on the substrate by arranging the X-ray shield has been described. However, in the case of an organic EL material or the like, the scattered rays ( The influence of reflected electrons) is also a major issue. In that case, after insulating the X-ray shield from other components (support shaft, rotary drive device, heater), grounding the X-ray shield prevents the reflected electrons from being scattered in the direction of the substrate, The influence of reflected electrons on the substrate can be suppressed. For example, the X-ray shield 11 shown in FIG. 2 may be insulated from the support shaft portion 11a and the heater 13, and the X-ray shield 11 may be connected to the ground.

It is principal part sectional drawing in the electron beam vapor deposition apparatus which concerns on embodiment of this invention. It is an AA arrow line view of FIG. It is a front view explaining the geometric relationship between the X-ray shield and the substrate in the electron beam evaporation apparatus. It is a side view explaining the geometric relationship between the X-ray shield and the substrate in the same electron beam evaporation apparatus. It is sectional drawing which shows the modification of the X-ray shield in the electron beam vapor deposition apparatus. It is BB sectional drawing of FIG. It is a side view which shows the modification of the X-ray shield of the electron beam vapor deposition apparatus. It is a side view which shows the modification of the X-ray shield of the electron beam vapor deposition apparatus.

Explanation of symbols

EB Electron beam K Substrate R X-ray 1 Vacuum vessel 2 Crucible 3 Electron beam irradiator 3a Beam generator 3b Beam introduction path 4 Substrate holder 11 X-ray shield 21 X-ray shield 22 Slit 31 X-ray shield 41 X-ray shield Body 42 Slit

Claims (3)

A thin film is formed by irradiating a vapor deposition material in a crucible arranged in a vacuum vessel with an electron beam, and depositing the vapor deposition material evaporated by the irradiation of the electron beam on the surface of a vapor deposition member arranged in the vacuum vessel. A vapor deposition apparatus for
An X-ray shield is disposed between the crucible and the member to be vapor-deposited so as to be rotatable around the horizontal axis, and has heating means for heating the X-ray shield.
In addition, when the X-ray shield is irradiated to the member to be vapor-deposited from the opening of the crucible, the projection portion of the X-ray shield by X-rays is at least larger than the thin film formation range of the member to be vapor-deposited. An electron beam evaporation apparatus characterized by that.   2. The electron beam evaporation apparatus according to claim 1, wherein a cylindrical body, a cylindrical body, a sphere, or a spherical shell is used as the X-ray shield.   While forming a through-hole penetrating in the vertical direction in the X-ray shield, the projected areas of the one-side through-hole portion and the other-side through-hole portion formed on both sides of the rotation axis do not overlap each other. 3. The electron beam evaporation apparatus according to claim 1, wherein the through-holes have different penetration directions.

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