JP2564387B2 - Laminate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvement of a laminate in which a metal thin film is laminated on a substrate by a vapor phase thin film forming method, and more specifically, the adhesion of the metal thin film to the substrate is improved. It relates to an improved laminate.

<Conventional Technology> In recent years, vacuum deposition technology has made remarkable progress, and due to its easy handling, it is replaced with a wet plating method, and electrical, electronic, and
Applications have been introduced in various industries such as optics, textiles, machinery, and construction.

For example, capacitors of electronic parts, gold and silver threads to be woven into clothes, and the like are metal films obtained by metallizing polymer films and fibers, respectively.

More recently, the demand for compact discs (CDs) and video discs (VDs) has increased dramatically due to the audio-visual (AV) boom.
Al vapor deposition film is coated.

However, when observing the formed Al vapor deposition film, it was found that many pinholes were generated. One of the causes of this is a material problem. By the way, it is generally said that there are few pinholes that easily migrate. Examples of such materials include precious metals such as Au. Therefore, Au coating has come to be applied to back coats such as CDs recently.

<Problems to be Solved by the Invention> However, substances that easily migrate, such as precious metals, generally have weak adhesion. In fact, when Au, Pt, Pd thin films, etc. are formed on glass and polymer film substrates, etc. by using the sputtering method etc., it has been confirmed that the formed film spontaneously peels off without applying mechanical force. . Therefore, in order to improve the adhesiveness of these, an intermediate layer is provided between the thin film and the substrate, and metal atoms are implanted into the substrate by the ion plating method, but the process becomes complicated. Not a suitable method.

<Means for Solving Problems> In the present invention, by adding indium and indium oxide having good adhesiveness to a metal having weak adhesiveness as described above, original properties (reflectance, corrosion resistance, pinhole It was made by finding that the direction of the adhesion between the thin film and the substrate can be easily aimed at without impairing the small amount).

That is, the present invention relates to a laminated body in which a metal thin film is laminated on a substrate by a vapor phase thin film forming method,
Alternatively, / In ₂ O ₃ is added.

From the above-mentioned points, the metal thin film in the present invention has poor adhesion to a substrate such as a polymer film and is not particularly limited as long as it requires improvement, and as such a metal, Au, Ag, Pd, P
Examples include t, Ni, Rh, Bi, Zn, Cu, Cd, Al, Sn, and Pb metals or alloys thereof. Among them, it is advantageous in that it has few pinholes, and adhesion to the substrate is poor.
It is effective for precious metals such as Pd that easily migrate.

The method for forming a metal thin film in the present invention is not particularly limited as long as it is a vapor phase thin film forming method for depositing a thin film on a substrate from a vapor phase represented by a sputtering method, and a vacuum vapor deposition method other than the sputtering method. , Well-known vapor phase thin film forming methods such as ion beam evaporation method, EB evaporation method, CVD method, ECR method, etc. can be applied,
If necessary, simultaneous vapor deposition or single vapor deposition is performed using these film forming methods.

The evaporation loss may be an alloy with In or a complex with In ₂ O ₃ , or may be In, In ₂ O ₃ or a simple substance of each metal. The atmosphere at the time of film formation is vacuum, and may be a normal sputtering gas or a gas containing a predetermined content of oxygen gas. The oxygen content in the case of using the oxygen-containing gas depends on the film forming method, but is usually in the range of about 10 vol% or less.

By the way, the laminate of the present invention can be applied to various aspects of the above-mentioned prior art. However, from the viewpoint of reflectance, corrosion resistance, few pinholes, etc. of the metal thin film, the metal film is used as a protective layer and / or a reflection layer. It is effectively used for an optical recording medium having a layer.

Here, the recording layer of the optical recording medium is formed by pits,
Examples include those that undergo a phase change upon irradiation with laser, those that form a valve, those that undergo magnetization reversal, etc.
In particular, it is suitable for a magneto-optical recording layer made of an amorphous alloy of rare earth-transition metal. This is because the thin film produced by the present invention has a large element as a protective layer, unlike a thin film intended only for light reflection like a CD. Examples of the substrate include a polymer resin substrate such as PMMA, polycarbonate, or an epoxy resin, a glass substrate, and the like. In particular, polycarbonate that is inexpensive and has excellent temperature characteristics and dimensional stability is preferably used.

It should be noted that the more the amount of In or / and In ₂ O ₃ added to the metal thin film, the better the adhesion, but the original properties of the metal thin film such as reflectance and durability deteriorate. Therefore, the In content is preferably 20 at% or less.

<Operation> In the laminate of the present invention described above, the metal thin film has good adhesion to the substrate, has a high reflectance depending on the substance, and has a small number of pinholes, and thus has high quality and good durability.
It can be applied to various fields. In particular, when the present invention is applied to an optical recording medium, it is possible to obtain a highly reliable optical recording medium which does not cause crack separation even in a weather resistance test.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

Example 1 A magneto-optical recording medium using a Pd thin film with In ₂ O ₃ added as a protective layer and a reflective layer was prepared and evaluated.

The Pd thin film with In ₂ O ₃ added was
A Pd plate was placed on a TO (indium tin oxide) target, and a film was formed in an atmosphere of 100% argon. Here, the sputtering pressure was 2 mm torr and the sputtering power was 4 W / cm ² . The content of In in this film was about 10 at% based on the result of AES analysis.

FIG. 1 is a sectional view showing the structure of a magneto-optical recording medium in which the above Pd thin film of this embodiment is used as a protective layer and a reflective layer. In FIG. 1, (11) is a polycarbonate (PC) substrate, (1)
2) is Ar / O ₂ = 90/10 (Vol
%) A dielectric layer made of an ITO film (film thickness is 800Å) formed by using a gas, (13) a transparent metal protective layer made of a Ti film (20Å) formed by the same sputtering method, and (14) the same sputtering. The magneto-optical recording layer made of a Tb ₂₃ Fe ₆₆ Co ₁₁ amorphous alloy formed by the method, (15) is the above-mentioned In ₂ O ₃ -added Pd film (thickness 1000 Å) of the protective layer and the reflective layer.

The magneto-optical recording medium of the above example was subjected to a weather resistance test at 70 ° C. and 90% RH. Normally, when the material of the recording layer (14) is oxidized, the coercive force and the Kerr rotation angle are lowered, but the magneto-optical recording medium of the above-mentioned embodiment according to the present invention is said to be at a practical level.
No cracking, peeling, deterioration of coercive force, or Kerr rotation angle was observed for more than 00 hours.

Furthermore, the reflectance of the film at 830 nm (wavelength of the semiconductor laser) was measured and found to be 80% or more.
From this, it was found that the metal film can be sufficiently used as a protective layer and a reflective layer.

Example 2 In and In ₂ O ₃ added P on a glass substrate as follows.
A t-film (film thickness 2000Å) was created. That is, using an Rf magnetron device, an In chip was placed on a Pt target to form a film in an oxygen atmosphere. Here, the sputtering gas is O ₂ / Ar = 10/90 (Vol%), and the sputtering gas pressure is 2 mmto
The rr and sputter power were 4 W / cm ² . The content of In in this film was about 15 at% based on the result of AES analysis.

Then, using the Pt film of this sample as an electrode, a redox reaction of water was performed. FIG. 2 is a current-voltage curve when an oxidation-reduction reaction of water is performed.

The sweep width of the voltage E was 0.1 to 1.4 V with respect to the standard hydrogen electrode (HNE), and the sweep was performed for 500 cycles. As a result, there was no change with time as shown in the figure. The vertical axis of the figure is the current I (mA / cm ² ) and the horizontal axis is the voltage E (V).

(Comparative Example) For comparison, Pd and Pt targets were sputtered in an Ar 100% atmosphere to form laminated bodies corresponding to Examples 1 and 2, respectively.

However, in all of these laminates, the Pd film and the Pt film peeled off when taken out from the chamber, and the durability test could not be performed.

<Effects of the Invention> As described above, according to the present invention, the adhesiveness to a substrate is good, cracks and peeling do not occur, the number of pinholes is small, the gas barrier property is good, the reflectance is high, and the corrosion resistance is high. It is possible to obtain a laminate provided with an excellent metal thin film. The metal thin film is most suitable for a reflection layer and a protective layer of an optical recording medium such as a CD, and therefore the present invention is particularly effective for the optical recording medium.
In addition, it goes without saying that it is widely applied to electrodes in the electrochemical field, ornaments, etc.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of the magneto-optical recording medium of Example 1, and FIG. 2 is a graph showing the results of an electrochemical endurance test using the Pt film of Example 2 as an electrode. 11: PC substrate, 14: Magneto-optical recording layer 15: Pd film with In ₂ O ₃ added

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-135359 (JP, A) JP-B 61-21827 (JP, B2) JP-B 62-16186 (JP, B2)

Claims (1)

(57) [Claims] 1. A laminate in which a metal thin film is laminated on a substrate by a vapor phase thin film forming method, the laminate is an optical recording medium, the metal thin film is a protective layer and / or a reflection layer thereof, and the metal film is In or / and In ₂ O on a metal film or alloy film selected from the group consisting of Au, Pd, Pt, Ni, Rh, Bi, Zn, Cu, Cd, Al, Sn and Pb.
A layered product containing ₃ added.