JP2992626B2 - Surface treatment method and device using ion beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel surface treatment method by ion beam irradiation and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, all surface treatments of materials by ion beam irradiation have been performed by irradiating ion beams from the material surface. On the other hand, a method of etching a material surface or forming a thin film by irradiating a solid material in a vacuum chamber with a gas jet while performing gas injection has been published in academic papers and the like. Has been put to practical use.

However, in the above-described method of irradiating an ion beam by injecting gas in a vacuum, since the vacuum chamber and the gas chamber are not completely separated, the gas pressure can be increased to about atmospheric pressure. However, there is a problem that the desired processing cannot be performed, and even if the processing can be performed, the processing speed becomes extremely slow.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and an apparatus for performing surface treatment of a material by ion beam irradiation reliably and at a relatively high speed.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above-mentioned problems of the prior art, and as a result, when performing ion beam irradiation on a material in a specific state, the surface treatment can be freely compared. The inventors have found that the present invention can be performed at a very high speed, and have completed the present invention.

That is, the present invention relates to the following surface treatment method and apparatus using ion beam irradiation.

[0007] 1. A method of treating a surface of a material by ion beam irradiation, wherein the back surface of the material is substantially exposed to a vacuum, and the back surface of the material whose surface is exposed to a gas atmosphere is irradiated with the ion beam. A surface treatment method using an ion beam.

[0008] 2. A gas chamber capable of inflow and outflow of an atmospheric gas is provided in or facing a vacuum chamber provided with an ion beam irradiation device, and a surface of a material to be irradiated with the ion beam is exposed to the gas chamber. A surface treatment apparatus by ion beam irradiation, wherein a window through which the material can be installed is provided in the gas chamber so that the back surface of the material is exposed to a vacuum chamber.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail along with its embodiments.

The material that can be surface-treated in the present invention is not particularly limited as long as it can transmit an ion beam. For example, a metal material (stainless steel, aluminum, nickel, beryllium, etc.), a polymer material (polyimide, polyamide, Polyether), a ceramic material, a glass material, a semiconductor material, and the like. In the present invention, particularly, surface treatment of a metal material, a polymer material, or the like can be suitably performed.

The ion beam in the present invention can be generated by a known ion beam generator. The thickness of the material is not particularly limited as long as the thickness allows the ion beam to pass therethrough.

The acceleration energy of the ion beam may be appropriately set depending on the type of the ion or the material, the thickness of the material, and the like. Usually, it is sufficient if the energy has enough energy to transmit the material. For example, when irradiating light ions such as hydrogen ions to a film-shaped material having a thickness of several μm or less, it may be about several hundred keV. On the other hand, when surface treatment is performed on a thick material or when heavy ions are irradiated, MeV
In some cases, the above acceleration energy is required.

As the ions used in the ion beam, virtually any ion can be used, and examples thereof include hydrogen ions (protons), helium ions, neon ions, and argon ions.

In the present invention, the back surface of the material is irradiated with an ion beam under vacuum. The vacuum state in the present invention is usually 10
It may be set to ^{over 7-10 over 8} Torr about, but may be changed depending on the type and other conditions of the ion. In the ion beam irradiation, the ion beam can be focused using a quadrupole lens or the like, whereby local processing of the material surface can be performed. Further, a fine structure can be formed by drawing the focused ion beam according to a previously designed shape. Note that the irradiation time of the ion beam can be set as appropriate depending on the type of material, the pressure of gas, and the like.

The ions (beams) irradiated from the back surface of the material pass through the material to excite atoms in the material and / or gas molecules in the gas atmosphere, and the reaction of the gas itself or the gas and the material on the surface of the material. Cause a reaction. Therefore, the gas used in the gas atmosphere of the present invention can be appropriately determined depending on the desired reactant, the type of material, and the like, and examples thereof include oxygen, nitrogen, chlorine, and carbon tetrachloride. As described above, various surface treatments such as etching, doping, and film formation can be performed by an arbitrary combination of a material and a gas. The gas pressure may be set according to the type of surface treatment, the type of material, and the like, but in the present invention, it can be set to about atmospheric pressure or higher. Generally, the higher the pressure, the higher the processing speed.

The surface treatment apparatus by ion beam irradiation of the present invention is provided with a gas chamber capable of inflow and outflow of an atmospheric gas in or facing a vacuum chamber provided with an ion beam irradiation apparatus. Characterized in that the gas chamber is provided with a window through which the material can be placed so that the surface of the material to be irradiated with the ion beam is exposed to the gas chamber, and the back surface of the material is exposed to the vacuum chamber. It is. FIG. 1 shows an outline of an example. In FIG. 1, the gas chamber is provided facing the vacuum chamber, and a window for irradiating an ion beam is provided at a boundary between the two chambers. The surface of the material exposed in the vacuum chamber is irradiated with the ion beam.

Known ion beam irradiators can be used. As the material of the vacuum chamber and the gas chamber, stainless steel, an aluminum-based material, or the like may be used. The vacuum chamber and the gas chamber or the apparatus of the present invention and the outside air are shut off by known grease, O-ring, gasket, etc., and are completely separated from each other. In the apparatus of the present invention, for example, a stainless steel plate or the like may be used as a support material for supporting a film or the like. In addition, the device of the present invention can be provided with a known semiconductor detector, a magnetic lens for focusing an ion beam, and the like, if necessary.

[0018]

According to the method of the present invention, the irradiation surface of the ion beam and the surface to be reacted with the atmosphere gas are completely separated from each other, and the atmosphere gas does not flow into the vacuum chamber. Control can be performed reliably and at high speed. As a result, various surface treatments such as etching, doping, and film formation can be performed freely and at high speed according to a predetermined design, depending on the irradiation conditions, the combination of the material and the atmosphere gas, and the like.

[0019]

EXAMPLES Examples and comparative examples will be shown below to clarify features of the present invention.

Example 1 A polyimide film having a thickness of 7.5 μm was coated with a 1.8 m diameter.
After sticking on a stainless steel plate having a hole of m with an adhesive, the plate was attached to a window of a gas chamber with an O-ring interposed therebetween. Next, the entire gas chamber was placed in a vacuum chamber, and the polyimide film was set so that the back surface was on the vacuum side and the surface was on the gas side. The gas chamber was filled with one atmosphere of oxygen, and the vacuum chamber was maintained at 10 ^-7 Torr. In this state, a hydrogen ion beam (acceleration energy: 1.5 MeV) focused to a width of about 50 μm was vertically incident on the back surface of the polyimide film. FIG. 1 shows the outline. Irradiation dose is 1 × 10
After irradiating with a hydrogen ion beam until it reaches ¹⁸ cm ^-2 ,
The state of the film was examined by Rutherford backscattering analysis (RBS). The result is shown in FIG.

FIG. 2 specifically shows the relationship between the energy of the scattered hydrogen ions (horizontal axis) and the number of hydrogen ions having that energy (vertical axis). Energy distribution of hydrogen ions that collided with the film: The interval between the high energy side edge and the low energy side edge (portion indicated by a broken line) in FIG. 2 (portion on the left side of “↓ C”) is almost proportional to the film thickness. Therefore,
In FIG. 2, assuming that the thickness at the irradiation amount of 2.8 × 10 ¹⁶ cm ⁻² is 100%, the thickness at the irradiation amount of 1.0 × 10 ¹⁸ cm ⁻² is about 40%. . In other words, it indicates that the polyimide film is thinned by the irradiation.

Inspection of the irradiated portion with an optical microscope reveals that the surface side of the polyimide film has been etched, and that a reaction between oxygen and the polyimide has occurred by irradiation with the ion beam.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of the device of the present invention.

FIG. 2 is a diagram showing a result of a state of a film subjected to a surface treatment in Example 1 examined by Rutherford backscattering analysis.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 21/3065 H01L 21/302 D (72) Inventor Akiyoshi Chatanihara 1-81-31 Midorigaoka, Ikeda-shi, Osaka Inside the Technical Research Institute (72) Inventor Nobuteru Tsubouchi 1-81-31 Midorioka, Ikeda-shi, Osaka Industrial Technology Research Institute Inside the Osaka Institute of Industrial Technology (72) Inventor Kenei Fujii 1-38-31 Midorioka, Ikeda-shi, Osaka Industrial Technology (56) References JP-A-63-206461 (JP, A) JP-A-63-240014 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23F 4/00 C23C 14/00-14/58 C23C 16/00-16/56 H01L 21/205 H01L 21/302 H01L 31/04 C23C 8/00-8/38

Claims (4)

(57) [Claims] 1. A method of treating a surface of a material by ion beam irradiation, wherein the back surface is substantially exposed to a vacuum and the surface is exposed to a gas atmosphere. An ion beam having an acceleration energy for exciting atoms in the gas and / or gas molecules in a gas atmosphere to cause a reaction between the material and the gas and / or the gas itself on the material surface. Surface treatment method for materials by irradiation. 2. The surface treatment method according to claim 1, wherein the material to be surface-treated is a metal material, a polymer material, a ceramic material, a glass material, or a semiconductor material. 3. The surface treatment method according to claim 1, wherein the ion beam is a hydrogen ion beam, a helium ion beam, a neon ion beam, or an argon ion beam. 4. A gas chamber capable of inflow and outflow of an atmospheric gas is provided in or facing a vacuum chamber provided with an ion beam irradiation device, and the surface of a material to be irradiated with an ion beam is gaseous. 4. The gas chamber according to claim 1, wherein a window is provided in the gas chamber so that the material is exposed so as to be exposed in the chamber and the back surface of the material is exposed in the vacuum chamber. An apparatus for a surface treatment method according to claim 1.