JPH04141580A - Laser flash vapor deposition device - Google Patents

Abstract

PURPOSE:To allow the varying of a vapor deposition speed and the stable stepwise administration of film thicknesses in number atom unit without intrusion of impurities into a thin film by disposing a movable target, a supporting part for an object for vapor deposition and a laser beam source, etc. CONSTITUTION:The material of the target 4 is evaporated by the laser beam when the surface of the target 4 is irradiated with the laser beam from the laser beam source 7 via an incident window 2 by a condenser lens 8 so as to form a light spot on this surface. The evaporated material, then, sticks onto the object 6 for vapor deposition placed before the target and the thin film formed of the number atomic layer of the target material 4 is formed. The density of the target 4 material sticking onto the object 6 for vapor deposition changes if the distance between the target 4 and the above-mentioned object 6 is changed by driving a motor 11 of a rotating mechanism and a supporting base of an X-Y translation mechanism in the case of the cylindrical target 4 and, therefore, the thickness of the film deposited by evaporation per unit pulse, i.e., vapor deposition speed, is changed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser flash vapor deposition apparatus that forms a thin film on the surface of an object by irradiating a target, which is a vapor deposition material, with laser light and vaporizing it. It is something.

[Conventional technology]

In order to produce a thin film, a conventional method of evaporating a deposition substance in a vacuum and depositing it on a substrate is widely used. Methods for vaporizing each substance include (1) direct resistance heating of the vapor deposited material, (2) method of bombarding and vaporizing the surface of the vapor deposited material with an electron beam or ion beam, and (3) enclosing sputtering gas. Methods include a method in which the sputtering gas is glow-discharged using an alternating current or direct current electric field, and the surface of the deposited material is bombarded with the generated ions and electrons to vaporize it; (4) and a method in which an alternating current magnetic field is further applied to the method in (3).

[Problem to be solved by the invention]

However, each of the above methods has problems such as limitations on the melting point of the vapor deposition material, selectivity of the vapor deposition material (insulating material 1 ferromagnetic material cannot be used), and limitations on the vapor deposition rate. Furthermore, when a sputtering gas is used, there is a problem in that the sputtering gas is mixed into the thin film as an impurity. Furthermore, these methods have the problem that the deposition rate fluctuates due to fluctuations in the flow of the sputtering gas or electron beam, making it difficult to control the film thickness.

In view of the above-mentioned problems, the present invention has no limitation on the melting point of the vapor deposition material or selectivity of the vapor deposition material (it is possible to change the vapor deposition rate, there is no mixing of impurities into the thin film, and it is possible to stably stabilize a number of atoms by changing the vapor deposition rate). The purpose is to provide a laser flash evaporation device that can control film thickness step by step.

[Means to solve the problem]

One of the racer flash vapor deposition apparatuses according to the present invention includes a tourniquet placed in a vacuum container, a laser light source, an optical system for focusing laser light from the laser light source onto the surface of the target, and the vacuum container. The target is movably supported so that the laser beam scans the surface of the target.

Another aspect of the laser flash vapor deposition apparatus according to the present invention includes a target placed in a vacuum container, a laser light source, and an optical system for focusing the laser light from the laser light source onto the surface of the target. , comprising a movable mirror disposed in the optical path of the laser beam and a deposition object support section disposed within the vacuum container, so that the beam of the laser beam scans over the surface of the target. The movable mirror is movably supported.

[For production]

According to the above configuration, in a high vacuum of 10-' Torr or less, a 10"
When a laser beam with an intensity of W/cr1 or more is irradiated, plasma vapor is generated from the target surface.

If a substrate-like object to be evaporated is placed near the target surface,
Ultra-thin films formed of several atomic layers are obtained.

The vapor deposition apparatus of the present invention has a feature that the film thickness can be controlled at the atomic layer level according to the number of laser pulses. Furthermore, since the vapor deposition apparatus of the present invention instantaneously turns a part of the target into plasma using a laser beam with high energy density, there is no restriction on the melting point of the material. Furthermore, since heating is performed by light, an insulator or a ferromagnetic material may be used, that is, there is no selectivity of the deposited material. Further, the vapor deposition rate can be changed by changing the distance between the target and the object to be vapor deposited to change the density of the target material adhering to the object to be vapor deposited, and the degree of freedom in setting the vapor deposition conditions is wide. Furthermore, since no sputtering gas is used, no impurities are mixed into the thin film.

In addition, in the vapor deposition apparatus of the present invention, if the surface of the same target is irradiated with laser light many times, the surface will be hollowed out and the spot diameter of the focused laser light will change, and the conditions for generating plasma will change, resulting in an increase in the deposition rate. is changing. For this purpose, it is necessary to efficiently supply a new target surface. Furthermore, in order to increase the surface area of the target and to focus the laser beam on the target under the same conditions, it is desirable that the target be cylindrical or flat. In the case of a cylindrical type, a rotation mechanism and an XY translation mechanism are required, and in the case of a flat plate type, an XYZ translation mechanism is required.

However, if a scanning optical system and an imaging optical system are provided and the laser beam is directly scanned optically, the mechanical mechanism becomes simple and becomes a high-speed and stable mechanism.

The deposition rate by the vapor deposition apparatus of the present invention is sensitive to the focusing conditions of the laser beam on the target surface, so no matter how deep the focal depth of the laser beam is, it is desirable that the shape accuracy of the target surface be maintained at 30 μm or less. . same(,
If the target is cylindrical, the rotation accuracy is 30μ.
It is desirable to keep it below m. for that purpose,
It is preferable that the support mechanism for the target be the same as the support mechanism used when processing the target.

Furthermore, artificial lattices are currently being actively developed, and there is a desire to evaporate several materials using the same device. In such a case, the surface of the target can be divided into several regions and provided with different materials. In that case, the surface of another material on the target may be irradiated with laser light by using the aforementioned moving mechanism or mechanism for optically deflecting the beam. For example, when producing a multilayer film for X-rays, two types of materials may be alternately deposited on a substrate-like object to be deposited using the above method. In particular, the method of deflecting a laser beam is advantageous because it does not require difficult mechanical operations such as moving a target within a vacuum container or opening/closing a shutter.

〔Example〕

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a schematic diagram of a first embodiment of a laser flash deposition apparatus according to the present invention. Reference numeral 1 denotes, for example, a cylindrical vacuum container having an entrance window 2 and an observation window 3, in which a cylindrical target 4 is rotatable around its axis by a rotation/movement support mechanism to be described later. , a substrate-shaped object 6 supported by a support stand 5 is movably disposed near the target 4 . 7 is a YAG laser light source provided outside the vacuum container 1; 8 is a condenser lens; the laser beam from the laser light source 7 is directed to the entrance window 2 by the condenser lens
The beam is irradiated to form a light spot on the surface of the target 4 through the beam. Note that the condenser lens 8 is movable in the optical axis direction.

FIG. 2 is a perspective view showing a support structure for the target 4 and the object to be deposited 6 in this embodiment. The target 4 is supported with its rotating shaft placed on a pair of support parts 9 having a 7-shaped notch, and these support parts 9 are connected to a target support stand IO.
is fixed.

Further, the shaft of the target 4 is connected via a joint 12 to the rotating shaft of a motor 11 fixed on the target support stand lo. Target support stage 10 is X stage 13
The X stage 13 is mounted on the X stage 14 so as to be movable in the X direction. X stage 1
4 is supported on a substrate (not shown) so as to be movable in the Y direction. These constitute a rotation/movement mechanism.

Further, the support stand 5 that supports the object to be deposited 6 is movable in the Y direction, that is, in the direction in which the distance from the target 4 changes. Since the vapor-deposited substance on the target 4 often flies in a direction perpendicular to the target surface, it is preferable to enter the laser light obliquely and to place the object 6 to be vapor-deposited in front of the laser convergence point on the target.

FIG. 3 is a partially cutaway side view showing the structure of the support portion of the target 4 in detail. The support part 9 includes: (1) a grooved support base 9a and a clamp base 9b fixed to the top surface of the support base 9a;
It is composed of. The left and right rotational shafts of the target 4 each include a spindle 4a having a conical tip and an outer cylinder 4b that bears the spindle 4a. Groove and clamp stand 9b
It is designed to be clamped and fixed between. The target 4 is rotatably supported by fitting and pressing the tips of the spindles 4a into the center holes 4c of the left and right end faces of the target 4. An L-shaped connecting member 4d is fixed to one end of the right spindle 4a, and its tip is connected to the engagement hole 4e on the right end surface of the target 4.
By being engaged with the target 4, the rotational force of the spindle 4a is transmitted to the target 4. or,
The other end of the right spindle 4a is connected to the rotating shaft of the motor 11 via the joint 12 as described above. Note that the left rotating shaft (spindle 4a and outer cylinder 4b) is removable.

Since the present embodiment is configured as described above, after focusing by moving the condenser lens 8 in the optical axis direction, the laser beam from the laser light source 7 is directed to the entrance window 2 by the condenser lens 8.
When the target material is irradiated to form a light spot on the surface of the target 4 through the laser beam, the target material is evaporated by the laser beam and attached to the deposition object 6 placed in front of it, and the target material is placed on the deposition object 6. A thin film consisting of several atomic layers of the substance is formed. The film thickness can be controlled at the atomic layer level according to the number of laser pulses. Furthermore, if the distance between the target 4 and the object to be evaporated 6 is changed by driving the support base 5, the density of the target material adhering to the object to be evaporated 6 changes, so the thickness of the film deposited per unit pulse is changed. ie the deposition rate can be varied. Of course, the number of pulses per unit time can also be changed.

Further, in this embodiment, since a part of the target 4 is instantaneously turned into plasma using a laser beam with high energy density, there is no restriction on the melting point of the material. Furthermore, since heating is performed by light, an insulating material or a ferromagnetic material may be used, that is, there is no selectivity of the deposited material.

By the way, if the surface of the target 4 is irradiated with laser light many times, the surface will gouge and the spot diameter of the laser light will change.
Although the conditions for generating plasma will change, the target 4 can be rotated by the motor 11 while the X stage 1
3 to move target 4 in the X direction,
The laser beam will scan the surface of the target 4,
A new target surface can always be provided. Therefore, the spot diameter of the laser beam is constant, and the conditions for generating plasma are constant, so that highly accurate vapor deposition can be performed. Note that the spot diameter of the laser beam can be finely adjusted by driving the Y stage 14 to slightly move the target 4 in the Y direction.

Furthermore, when performing the above-mentioned scanning or replacing the target 4, it is necessary that the focusing position of the laser beam on the surface of the target 4 does not fluctuate or that the spot diameter does not change. I don't need it. The target 4 of this embodiment is mounted on a shape processing machine whose processing accuracy is determined by the rotational accuracy of the spindle 4a (the processing accuracy of the outer cylinder 4b is also affected), with the center hole 4c that is first machined as a reference, and the surface is processed. will be carried out. in general,
Since the spindle 4a of the shape processing machine has a high rotational accuracy of 2 μm or less, the processed target 4 has a high degree of circularity. In this embodiment, the spindle 4a is fitted and pressed into the center hole 4C and rotated so as to reproduce the machining conditions, so that the same rotational accuracy and roundness as when machining can be reproduced. In addition, the V-groove of the support base 9 that supports the rotating shaft (spindle 4a and outer cylinder 4b) can be machined with high precision of several μm or less, so even if the rotating shaft is temporarily removed and the target 4 is replaced, High rotation accuracy can always be maintained.

FIG. 4 is a perspective view of the main part of the second embodiment, which shows a laser beam from a laser light source 7 reflected by a rotating polygon mirror 15 (polygon mirror) and then a condensing lens 8 (fθ lens).
The target 4 is irradiated through the rays. In this configuration, the target 4 is
Since the upper surface is scanned in the X direction with a laser beam, a mechanism for moving the target 4 in the X direction is not necessary.

In any of the above embodiments, if a plurality of substances are to be deposited using one apparatus, the surface of the target 4 may be deposited in several areas, for example, as shown in FIG. 5(A) or (B). A
, H, and provide different materials, and irradiate the surfaces of the different materials on the target 4 with laser light using the above-mentioned moving mechanism or optical beam deflection mechanism.

Further, unlike both of the above embodiments, the spindle 4a and the target 4 are machined as one unit, and the spindle 4a is supported by the support part 9 with the outer cylinder 4b fitted, and one support part 9 is A method may be adopted in which the target 4 is replaced by moving it.

Furthermore, a planar plate-like target may be used instead of the cylindrical target 40, and a mechanism for moving the target in the X and Z directions may be used so that the laser beam scans the surface of the target. Regarding this, the rotating polygon mirror 15 may be used as in the second embodiment. Furthermore, it goes without saying that by dividing the surface of a flat plate-like target into a plurality of regions and providing different materials thereon, it is possible to deposit a plurality of materials using one apparatus.

〔Effect of the invention〕

As mentioned above, the laser flash vapor deposition apparatus according to the present invention has no restriction on the melting point of the vapor deposition material and no selectivity of the vapor deposition material,
It has important practical advantages in that the deposition rate can be varied, impurities are not mixed into the thin film, and the film thickness can be stably controlled step by step in units of several atoms.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a first embodiment of a laser flash vapor deposition apparatus according to the present invention, FIG. 2 is a perspective view showing a support structure for a target and an object to be deposited in the first embodiment, and FIG.
The figure is a partially cutaway side view showing in detail the structure of the support part of the target in the first embodiment, FIG. 4 is a perspective view of the main part of the second embodiment, and FIG. 5 is a perspective view of a modified example of the target. be. DESCRIPTION OF SYMBOLS 1...Vacuum container, 2...Incidence window, 3...Observation window, 4...Target, 5...Support stand, 6...
. . . Object to be deposited, 7. . . YAG laser light source, 8.
...Condensing lens, 9...Support part, 10...Target support stand, 11...Motor, 12...Joint, 13...X stage, 14...・Y stage, 15...Rotating polygon mirror. Al, (B)

Claims (2)

[Claims] (1) A target placed in a vacuum container, a laser light source, an optical system for focusing the laser beam from the laser light source onto the surface of the target, and a support for the object to be deposited placed in the vacuum container. A laser flash vapor deposition apparatus comprising: a laser flash vapor deposition apparatus, wherein the target is movably supported so that a beam of the laser light scans a surface of the target. (2) A target placed in a vacuum container, a laser light source, an optical system for focusing the laser light from the laser light source onto the surface of the target, and a movable mirror placed in the optical path of the laser light. and a deposition object support section disposed in the vacuum container, the movable mirror being movably supported so that the laser beam scans over the surface of the target. Vapor deposition equipment.