JP3802246B2 - Deposition equipment - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to a film forming apparatus provided with a high frequency induction plasma generator.
[0002]
[Prior art]
The film formation method in which the target is heated locally by applying a very high energy beam to the target, the material constituting the target is instantaneously evaporated, and the evaporated particles adhere to the substrate in the form of a film. It is possible to obtain a film having a composition ratio faithful to the composition ratio of the material comprising
[0003]
FIG. 1 shows an outline of a laser ablation vapor deposition apparatus as an apparatus embodying such a film formation method.
[0004]
In the figure, 1 is a vacuum chamber, and a target 2 is provided in the center of the interior. The target is mounted on a rotation shaft 4 of a rotation drive mechanism (comprising a motor or the like) 3 provided outside the chamber. A substrate 5 is disposed obliquely above the target (approximately 20 ° apart from the target surface). The substrate is attached to the front end surface of a substrate holder 7 that is rotated by a rotation drive mechanism (comprising a motor or the like) 6 provided outside the chamber. In addition, a heater 8 is provided inside the substrate holder to allow a heating current to flow from a heating power source (not shown) provided outside the chamber. Reference numeral 9 denotes a laser generation source provided outside the chamber. The laser beam from the laser generation source is collected by the focusing lens 10 and is attached to the chamber wall on the target 2 through a window 11 made of, for example, quartz glass. Irradiated. 12 is a gate valve and 13 is an exhaust device such as a cryopump.
[0005]
Next, the film forming operation of such an apparatus will be described. A target obtained by sintering a powder of a superconducting material such as YBCO is prepared as the target, and a pulse laser source is used as a laser generation source.
[0006]
First, the gate valve 12 is opened, and the inside of the chamber 1 is brought into a high vacuum state of about 10 ⁻⁶ Pa by the exhaust device 13. At the same time, the target 2 and the substrate 5 are rotated by the rotation driving mechanisms 3 and 6 through the rotation shaft 4 and the substrate holder 7, respectively. Further, the substrate 5 is heated by the heater 8. In this state, a laser beam is generated in a pulse form from the laser generation source 9 and is condensed on the target 2 by the condenser lens 10. Then, the portion of the target 2 that has been irradiated with the laser beam is heated to an extremely high temperature, and the material constituting the target 2 is instantly evaporated. When the material forming the target 2 evaporates in this way, a high-temperature vapor in a plasma state called bloom is generated between the target 2 and the substrate 5, and the same composition material as the composition material forming the target 2 is evaporated on the substrate 5. Particles adhere to the film.
[0007]
Such a film formation method can be applied to formation of a ferroelectric film or the like in addition to formation of a superconducting film.
[0008]
[Problems to be solved by the invention]
The laser ablation deposition apparatus needs to be replaced with about 100 pulses, depending on the type of laser source. That is, the laser source must be replaced relatively frequently and is cumbersome to operate. Moreover, this exchange generally requires a running cost of several hundred thousand yen. Accordingly, if it is considered that a film of about several tens of nanometers per pulse is formed, it takes several thousand to several tens of thousands of yen to form a film of only 1 μm. As the film formation area increases, the film formation rate per pulse decreases, so that a film formation apparatus using a laser for evaporation of the target becomes very expensive.
[0009]
An object of the present invention is to provide a novel film forming apparatus that solves such problems.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a film forming apparatus in which a target and a substrate are arranged in a vacuum chamber, and the composition material of the target is evaporated to adhere to the substrate in a film form by irradiating the target with light. In the membrane apparatus, a high-frequency plasma generator is disposed outside the vacuum chamber, the light from the high-frequency plasma generated by the high-frequency plasma generator is condensed into the chamber through a transparent window, and the target is irradiated with the light. It is characterized by being made.
[0011]
The film forming apparatus according to claim 2 is characterized in that the window forms a condensing lens.
[0012]
In the film forming apparatus according to claim 3, a coil is wound around a plasma generating tube provided with a gas introduction hole, and a high frequency induction plasma is generated in the tube by supplying a high frequency to the coil. The target is irradiated with light from the opposite side of the plasma.
[0013]
The film forming apparatus according to claim 4 is characterized in that a shutter is provided between the high-frequency plasma and the target.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 2 is a schematic view of a film forming apparatus showing an example of the present invention. In the figure, the same reference numerals as those used in FIG. 1 denote the same components.
[0017]
The difference between the structure of the film forming apparatus shown in FIG. 2 and the structure of the film forming apparatus shown in FIG. 1 is the structure of the means for evaporating the target. This will be described below.
[0018]
In the figure, reference numeral 14 denotes a cylindrical tube made of an insulating material, around which an RF coil 16 connected to a high-frequency power source 15 is wound. The RF coil may be wound so as to be embedded in the tube. A transparent quartz glass lid 17 is provided at one end of the tube, and a gas introduction hole 18 is provided at a location near the lid. A chamber 19 is connected to the other end of the tube, and an exhaust device (not shown) is connected to the tip of the chamber. The cylindrical tube 14 is actually composed of an inner tube and an outer tube which are conventionally known, and a double tube structure in which cooling water flows between these tubes is used. Reference numeral 20 denotes a focusing lens attached to the wall of the chamber 1 at a predetermined interval with respect to the lid 17, and reference numeral 21 denotes a shutter disposed between the lid 17 and the focusing lens 20 and has a water cooling structure.
[0019]
Next, the operation of the film forming apparatus having such a configuration will be described.
First, the gate valve 12 is opened, and the inside of the chamber 1 is brought into a high vacuum state of about 10 ⁻⁶ Pa by the exhaust device 13. At the same time, the target 2 and the substrate 5 are rotated by the rotation driving mechanisms 3 and 6 through the rotation shaft 4 and the substrate holder 7, respectively. Further, the substrate 5 is heated by the heater 8.
[0020]
In this state, the shutter 21 is closed, the high frequency output from the high frequency power supply 15 is set to about 2 KW, and the pressure in the cylindrical tube 14 and the chamber 19 is 133 Pa (1 Torr) or less by an exhaust device (not shown). Exhaust. Then, an inert gas such as Ar gas is allowed to flow from the hole 18 into the cylindrical tube 14 at about 30 L / min. Then, low temperature plasma (glow plasma) is once excited in the tube. At this time, the pressure in the tube is about 1330 to 1 × 10 ⁵ Pa (10 to 760 Torr), and while maintaining this pressure state, the high frequency output from the high frequency power supply 15 is increased to about 10 KW, In addition to the Ar gas, air is started to flow at about 10 L / min, and from this point, the amount of Ar gas introduced is gradually reduced to zero. Then, the high frequency output is increased to about 30 KW. When the air plasma (thermal plasma) in the tube is stabilized through such a process, the shutter 21 is opened.
[0021]
Therefore, the light emitted from the thermal plasma generated in the tube is light having a wavelength of several hundred nm to 1300 nm, and high illuminance light enough to burn a resin away from the RF coil 16 by about 200 mm. Such high illuminance light is condensed by the condenser lens 20 and applied to the target 2. Then, the portion of the target that has been exposed to high illuminance light is heated to an extremely high temperature, and the material constituting the target 2 is instantly evaporated. As the material forming the target 2 evaporates in this manner, a high-temperature vapor in a plasma state called bloom is generated between the target 2 and the substrate 5, and a film of the same composition material as the composition material forming the target 2 is formed on the substrate 5. Is formed.
[0022]
In the above-described embodiment, the light from the target side portion (the opposite side portion of the thermal plasma) of the thermal plasma generated in the cylindrical tube 14 is used for the evaporation of the target 2, but the chamber 19 is compact. The lid 17 may be attached to the tip thereof, and the light from the front part of the thermal plasma may be used.
[0023]
Further, the target may be irradiated with a light beam from thermal plasma in a pulse manner by controlling the opening / closing cycle of the shutter 22. In this way, the irradiation amount of the light beam from the thermal plasma can be controlled according to the type of the target.
[0024]
In addition, a scanning mechanism including a galvanometer mirror or the like may be provided in the optical path of light from the thermal plasma, and light may be applied to a wide range of targets by scanning the target with light from the plasma. By doing so, it is possible to use a wide range of targets and increase the film-forming area on the substrate.
[0025]
Moreover, in the said Example, although the thermal plasma was formed with air, you may make it form with other gas, for example, oxygen gas, nitrogen gas, etc.
[0026]
In the above embodiment, in order to simplify the apparatus configuration, the condensing lens is configured so as to serve as a window for passing light from the thermal plasma in the target direction. A transparent window may be provided between the chambers and separately provided on the chamber wall.
[0027]
【The invention's effect】
The present invention evaporates a substance that forms a target by irradiating light from a high-frequency induction thermal plasma, and deposits a film of the same substance as the composition material of the target on a substrate. There is no need to replace the induction thermal plasma source, and no maintenance is required other than periodic inspection of the high frequency induction thermal plasma source, so that stable and continuous light irradiation can be performed for a long time. For this reason, both the cost and the operation are remarkably advantageous as compared with the prior art.
[0028]
In addition, by changing the high-frequency output, the diameter of the tube around which the RF coil is wound, etc., light with various intensities and cross-sectional areas can be obtained, so that the film application range is expanded.
[Brief description of the drawings]
FIG. 1 shows an outline of a conventional film forming apparatus.
FIG. 2 shows an outline of an embodiment of a film forming apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,19 ... Chamber, 2 ... Target, 3, 6 ... Rotation drive mechanism, 4 ... Rotating shaft, 5 ... Substrate, 7 ... Substrate holder, 8 ... Heater, 12 ... Gate valve, 13 ... Exhaust device, 14 ... Cylindrical tube , 15 ... high frequency power supply, 16 ... RF coil, 17 ... lid, 18 ... hole for introducing gas, 20 ... focusing lens, 21 ... shutter

Claims (4)

  In a film forming apparatus in which a target and a substrate are arranged in a vacuum chamber, and the composition material of the target is evaporated to be deposited on the substrate by irradiating the target with light. A generator is arranged, the light from the high-frequency plasma generated by the high-frequency plasma generator is condensed into the chamber through a transparent window, and the target is irradiated with the light. A film forming apparatus. The film forming apparatus according to claim 1 , wherein the window forms a condenser lens. A coil is wound around a plasma generation tube provided with a gas introduction hole, and a high frequency induction plasma is generated in the tube by supplying a high frequency to the coil, and light from the opposite end portion of the high frequency induction plasma is a target. The film-forming apparatus according to claim 1 , wherein the film-forming apparatus is configured to irradiate the film. 4. The film forming apparatus according to claim 1 , wherein a shutter is provided between the high frequency plasma and the target.

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