JPH0676659B2 - Method for producing aluminum material having crystalline aluminum oxide metamorphic layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention utilizes applications in which electrical characteristics of electronic materials, semiconductor materials, etc. are utilized, as well as various characteristics such as wear resistance, heat resistance and corrosion resistance. The present invention relates to a method for producing an aluminum material having a crystalline aluminum oxide metamorphic layer suitable for applications and the like.

(Prior Art) In recent years, attempts have been made to develop various applications by utilizing the fact that the material on which a thin layer of aluminum oxide is formed has various characteristics such as electrical insulation and abrasion resistance of aluminum oxide.

In order to form a thin aluminum oxide layer for these applications, reactive evaporation and CVD (Chemica
Vapor Deposition), sputtering method, ion plating method, etc.

(Problems to be Solved by the Invention) However, in the above-mentioned method, since the aluminum oxide thin layer is basically adhered to the aluminum surface in a coating state, peeling due to a thermal cycle or mechanical impact occurs. In addition, a thick film with a certain thickness or more (for example, 1 to 5 μm in the ion plating method) in order to satisfy desired characteristics.
There was a problem such as needing. In addition, when used for electronic materials, it is desirable to use a crystalline aluminum oxide layer in view of its characteristics. However, in each of the above-mentioned production methods, a crystalline aluminum oxide layer is obtained, so a crystalline aluminum oxide layer is heat treated after film formation. It is necessary to carry out the crystallization operation as a post-treatment, so that the production cost rises and problems such as softening of the aluminum substrate itself due to heating and peeling of the film occur.

As described above, it is difficult to obtain the one in which the metamorphic layer in which aluminum is metamorphosed into the layered crystalline aluminum oxide is formed inside the surface layer portion of the aluminum material.

The present inventors have attempted to apply an ion implantation method applied as a doping method to semiconductors, and as a result, perform oxygen ion implantation on the surface of an aluminum material under a specific range of acceleration energy and an oxygen ion implantation amount. Have found that a crystalline aluminum oxide metamorphic layer can be formed by a one-step treatment.

Incidentally, the oxygen ion implantation technique is utilized as a technique for introducing SiO ₂ into a silicon layer as disclosed in, for example, Japanese Patent Laid-Open No. 58-84422, but the SiO ₂ produced is amorphous. A heat treatment for crystallization was necessary.

The object of the present invention is to produce an aluminum material having a crystalline aluminum oxide metamorphic layer, which is a thin layer and has excellent adhesion, and which has various characteristics such as electrical characteristics, mechanical characteristics and chemical stability equivalent to or better than conventional ones. According to the present invention, the above aluminum material can be obtained at low cost in a short time.

(Means for Solving the Problem) The present invention uses acceleration energy of 10 to 30 on the surface of an aluminum material.
Crystallinity characterized by forming a crystalline aluminum oxide metamorphic layer by implanting oxygen under the conditions of 0 KeV oxygen ion implantation amount [0 ₂ ⁺ ] of 5 × 10 ¹⁷ to 2 × 10 ¹⁸ ions / cm ² . The gist is a method for producing an aluminum material having an aluminum oxide metamorphic layer, whereby a crystalline aluminum oxide metamorphic layer having a film thickness of 0.1 to 0.5 μm is generated by ion implantation, and the oxygen ion implantation amount is adjusted to adjust the inside of the surface layer portion. Further, a metamorphic layer in which aluminum is transformed into a layered crystalline aluminum oxide and a metamorphic layer in which the entire surface layer portion is transformed into a crystalline aluminum oxide layer are formed.

In the present specification, the "aluminum material" means a thin film foil made of aluminum and an aluminum alloy having a wall thickness of 50 μm or more, a plate material, a mold material, and aluminum and an aluminum alloy integrated with another base material, that is, 200 ° C. A material that does not evaporate or degas at the above-mentioned heat resistance and vacuum during ion implantation, such as other aluminum alloys,
Metal materials such as copper, inorganic materials such as glass and ceramics, substrate materials such as insulating plastic materials such as epoxy resin and polyimide resin, and thin films, foils, plates, etc. made of aluminum and aluminum alloy of 5 μm or more, etc. Are collectively referred to.

The crystalline aluminum oxide metamorphic layer is subjected to a film removal treatment by a conventional method, for example, a degreasing treatment with an organic solvent such as acetone or trichloroethylene, and then a vacuum degree of 7 × 10 ⁻⁷ to 2 × 10 ^−6.
Oxygen ions on the surface of aluminum material in an ion implantation chamber held at Torr at an acceleration energy of 10 to 300 KeV of 5 × 10 ¹⁷
Implanted at an implantation dose (as 0 ₂ ⁺ ) of ˜2 × 10 ¹⁸ ions / cm ² to form a thickness of 0.1 to 0.5 μm.

In this case, the reason for setting the acceleration energy to 10 to 300 KeV is 30.
With acceleration energy exceeding 0 KeV, irradiation of oxygen ions causes irradiation damage, dislocation, etc. on the aluminum material, which adversely affects the coating and the substrate itself.
If it is less than 10 KeV, a sputtering effect occurs and an appropriate ion implantation effect is not exhibited, which is not desirable.

In addition, when the required characteristics are high level like an electronic material, it is more required to homogenize the crystalline aluminum oxide layer, and in such a case, oxygen ion implantation with an acceleration energy of 50 to 200 KeV is preferable. By this, a homogeneous crystalline aluminum oxide metamorphic layer can be formed.

Also, when the irradiation dose [0 ₂ ⁺ ] of oxygen ions exceeds 5 × 10 ¹⁷ ions / cm ² , a seed crystal layer of crystalline aluminum oxide is formed, and by setting it to 1 × 10 ¹⁸ ions / cm ² or more, , It is possible to eliminate the Gaussian distribution of oxygen ions in the crystalline aluminum oxide metamorphic layer in the film thickness direction, to make the oxygen ion concentration uniform, and to develop stability of the characteristics, and to increase stoichiometry with increasing oxygen ion implantation amount. Although it can be said that it is a crystalline aluminum oxide layer, the layer thickness increases, but the thickness of the metamorphic layer can be increased even if the implantation exceeds 2 × 10 ¹⁸ ions / cm ² , but the improvement in characteristics is due to the withstand voltage, etc. No significant improvement is observed except for.

In order to maintain the degree of vacuum in the ion implantation chamber as described above, the degree of vacuum is set to about 5 × 10 ⁻⁷ Torr in advance and then the residual gas is replaced with oxygen gas so that impurities are not mixed by the ion implantation. It can be lowered.

Furthermore ions implanted rather than the state of [0 ^+] found the following [0 ₂ ^+] state more preferable can shorten the ion implantation time.

Further, in ion implantation, a masking plate (for example, an aluminum material) is brought into close contact with the substrate to be treated, and oxygen ion implantation is performed only in the opening of the masking plate or a portion where the masking plate is not in contact, so that a portion of the substrate Only the metamorphic layer may be formed.

When the metamorphic layer formed as described above is formed as a crystalline aluminum oxide metamorphic layer inside the surface layer portion of the aluminum material, conductive Al is formed on both sides of the insulating crystalline aluminum oxide layer in the central portion. Since it has an existing structure, it can be used as a functional material such as a semiconductor material having both sides or one of them as electrodes, and in the case of a metamorphic layer in which the entire surface layer portion is a crystalline aluminum oxide layer, the crystalline It can be applied to various applications where the material properties possessed by aluminum oxide can be utilized.

Further, in the case of an aluminum material having a crystalline aluminum oxide metamorphic layer formed inside the surface layer portion, it may be used as a material for forming an aluminum nitride layer on the crystalline aluminum oxide metamorphic layer by, for example, implanting nitrogen ions. Can be used.

(Function) The present invention forms a crystalline aluminum oxide metamorphic layer in a surface layer of an aluminum material by one step by setting the acceleration energy of oxygen ion implantation into the aluminum material and the oxygen ion implantation amount within a specific range. AES (Auger Electron Spectroscopy) / ESCA (Electr
on Spectroscopy for Chemical Analysis), the structure was analyzed and identified by X-ray diffraction and a transmission electron microscope. As a result, it was found to be an aggregate of polycrystalline γ-Al ₂ O ₂ .

(Effects of the Invention) The present invention is to perform oxygen ion implantation on the surface of an aluminum material with a specific acceleration energy and an oxygen ion implantation amount as described above, whereby the intrinsic properties possessed by the crystalline aluminum oxide metamorphic layer are sufficiently satisfied. (A) It is possible to obtain an aluminum material having an extremely thin film thickness and sufficiently exhibiting the material properties of crystalline aluminum oxide.

(B) Since it is possible to obtain an aluminum material as a crystalline aluminum oxide metamorphic layer from the extreme surface of the aluminum material, which has been difficult with the conventional method, it is possible to manufacture separated elements.

(C) Since the metamorphic layer integrated with the base material is formed, an extremely excellent one against mechanical or thermal shock can be obtained.

And the like, and is extremely effective in industry.

(Examples) The present invention will be described in detail with reference to Examples, but the present invention is not limited thereto, and appropriate modes can be adopted as described above.

Example 1 An aluminum plate (thickness: 0.1 mm) having a purity of 99.99% as a substrate for an integrated circuit was degreased with trichlorethylene, ultrasonically washed with acetone, and further washed with water to clean the surface.

Then, oxygen ion [0 ₂ ⁺ ] was irradiated onto the surface of the aluminum plate kept at room temperature at an acceleration energy of 150 KeV in an ion implantation chamber with a vacuum degree of 1 × 10 ^-6 Torr, and the ion implantation dose was set to 5
× 10 ¹⁷ ions / cm ² (Sample a), 1 × 10 ¹⁸ ions / cm
² (Sample b), 2 × 10 ¹⁸ ions / cm ² (Sample c) 3
A sample was prepared. (Ion implanter is RIKEN 200KV Low Ca
Using rrent Implanter) Fig. 1 shows the result of measuring the distribution state of elements from the surface layer to the depth direction by AES for the three obtained samples.

According to this, in the sample a of FIG. 1 (a), the seed formation of aluminum oxide is linear, and as in the sample b of FIG. 1 (b), the crystallinity is about 1 × 10 ¹⁸ ions / cm ² . A product having an aluminum oxide metamorphic layer formed inside the surface layer was obtained, and when the concentration was about 2 × 10 ¹⁸ ions / cm ² as in sample c in FIG. It is shown that

Subsequently, the sample c was treated with a bromine methanol solution, the metamorphic layer was separated and extracted, and then its composition and crystal structure were examined.

The metamorphic layer was confirmed to be γ-Al ₂ O by electron diffraction with a transmission electron microscope.
Identified as ₃ . On the other hand, considering that the peak of γ-Al ₂ O ₃ could not be detected by X-ray diffraction, it is presumed that the produced metamorphic layer is an aggregate of γ-Al ₂ O ₃ microcrystals.

[Brief description of drawings]

FIG. 1 shows (a), (b) and (c) showing the results of elemental analysis in the depth direction from the surface layer by AES analysis of each sample obtained in Example 1. FIG. 6 is a diagram showing a change in sputtering time with respect to FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaya Iwaki 2-1, Hirosawa, Wako-shi, Saitama, RIKEN (56) References JP-A-60-128262 (JP, A) JP-A-53-31971 ( JP, A)

Claims (1)

[Claims] 1. An aluminum material having an acceleration energy of 10 to 30.
0 KeV, oxygen ion implantation amount [O ₂ ⁺ ] is 5 × 10 ¹⁷ to 2 × 10 ¹⁸
A method for producing an aluminum material having a crystalline aluminum oxide metamorphic layer, comprising forming a surface-modified layer comprising a crystalline aluminum oxide metamorphic layer by implanting oxygen ions under the condition of ions / cm ² .