JP3515966B2 - Method for manufacturing magneto-optical recording element - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording element in which an optical recording layer including a dielectric layer and a magnetic recording layer is formed on one main surface of a bombarded resin substrate. And a method for producing the same. 2. Description of the Related Art Conventionally, when a thin film is formed on one principal surface of a substrate, a gas introduced into a chamber is brought into a plasma state, and gas ions are made to collide with the substrate surface to thereby form a substrate. In some cases, a so-called bombarding process is performed to cut the chemical bond of the substrate and chemically activate the same to improve the adhesion between the substrate and the film formation layer. [0003] However, in this bombardment treatment, it is a general method to apply a voltage to a pair of electrodes provided in a chamber to convert the gas into plasma. When the electrode for bombardment is sputtered, the constituent materials of the electrode are deposited and deposited on the substrate, and when a thin film is formed on this deposited layer, impurities diffuse from the deposited layer to the thin film, and the original characteristics of the thin film are reduced. Problems such as deterioration occur. In particular, in the case of manufacturing a magneto-optical recording element, before forming an inorganic dielectric layer or a magnetic layer on a resin substrate, the adhesion between the organic substrate and the inorganic film-forming layer is improved. In some cases, bombardment processing is performed for the purpose of obtaining reliability, and the contamination of the film formation layer by the above-mentioned electrode material has been a serious problem. For this reason, conventionally, a gas having as small a molecular weight as possible has been used for the bombarding process, and the sputtering of the electrode has been mainly suppressed as much as possible. However, this method only suppresses the rate at which the bombarding electrode is consumed by sputtering, and even a small amount of the sputtered electrode material adheres to the substrate surface on the substrate surface. In some cases, the characteristics and reliability were adversely affected. Therefore, the present invention solves the above-mentioned problem,
It is an object of the present invention to provide a method of manufacturing a magneto-optical recording element that does not depend on the type of gas used for bombardment processing and that does not cause deterioration in characteristics and reliability, and to provide a magneto-optical recording element having a novel layer configuration. . According to the present invention, there is provided a method of manufacturing a magneto-optical recording element, comprising: disposing a resin substrate and an electrode made of a non-grounded Ti transition metal in a chamber;
A gas introduced into the chamber by applying a voltage to the electrode is turned into plasma to bombard one main surface of the substrate, and a dielectric containing silicon nitride as a main component is formed on one main surface of the bombarded substrate. A magnetic layer of a rare earth-transition metal layer. Embodiments according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, first, electrodes 1 and 1 for bombarding and a substrate 2 made of polycarbonate are arranged in a chamber C. Here, the substrate 2 is grounded, but the electrodes 1 and 1 are not grounded for the reason described later. Next, after the inside of the chamber C is evacuated to a high vacuum of 1 × 10 ⁻⁵ Torr or less, nitrogen gas is introduced, and 0.1 to 1 mT
orr. Then, 0.5 to 2 kV, 60
Hz alternating current, nitrogen gas into plasma state, about 1
Bombarding the substrate 2 is performed for about 10 minutes. here,
The materials of the electrodes 1 and 1 include Ti, which is a IVA group transition metal,
Various electrodes each containing Cr, Fe, Co, and Ni as the main transition metals of the VA group were used. After the bombarding process, the substrate 2 is transferred to a film forming chamber different from the chamber (bombarding tank) C,
The film formation chamber is evacuated to about 1 × 10 ⁻⁷ to 10 × 10 ⁻⁷ Torr. Then, introduce argon gas into the deposition chamber to
mTorr, high frequency output (input power to target material)
A high-frequency sputtering is performed while maintaining the horizontal magnetic field on the target material surface at a predetermined magnetic field at 0.5 to 1.0 kW, and then a protective layer of resin is applied by spin coating to form a magneto-optical recording element as shown in FIG. D was formed. That is, on the substrate 2, an inorganic layer Lb of about 5 to 30 °, a first dielectric layer L1 (Si-N based amorphous layer of about 1500 °), and a magnetic layer L2 (rare earth of about 500 °) Transition metal-based, for example, Gd-Dy-Fe-based amorphous layer, second dielectric layer L3 (Si-N-based amorphous layer of about 500 °), reflective layer L4 (about 800 ° of metallic aluminum) Layer) and a protective layer L5 (an ultraviolet curable resin layer of about 50 μm) were sequentially laminated. If the thickness of the inorganic tank Lb is too large, C
Since the / N ratio decreases, it is desirable that the angle is about 5 to 30 ° in order to maintain an appropriate C / N ratio. Next, after bombarding the substrate 2 using various electrodes as shown in Tables 1 and 2, the reliability (high-temperature and high-humidity test; JIS K5400) of each of the produced magneto-optical recording elements was measured. ) And electrical characteristics (C / N ratio) will be described. The electric characteristics were measured at a position of about 24 mm from the center of the substrate in a film formation region of the magnetic layer at 20 to 42 mm from the center of the substrate. [Table 1] [Table 2] As is clear from the results, when the bombardment electrode was mainly composed of Fe or Co, 250 hours or more after the sample was put into the high-temperature and high-humidity tank, the dielectric layer was observed by an optical microscope. Peeling of the film was observed in L1 and the magnetic layer L2, and it was found that the corrosion was significantly advanced. Further, when the bombardment electrode was mainly composed of Cr or Ni, almost no corrosion was observed, but the C / N ratio was low and the electric characteristics were deteriorated. On the other hand, when the inorganic layer Lb was made of a Ti transition metal, no corrosion of the dielectric layer L1 or the magnetic layer L2 was observed, and the electrical characteristics were also very good. As described above, by interposing the inorganic layer Lb containing Ti transition metal as a main component by an appropriate thickness (5 to 30 °) between the dielectric layer L1 and the substrate 2,
The adhesion between the film and the film formation layer can be improved, the corrosion resistance of the film formation layer can be improved, and the reliability can be improved, and the deterioration of the electric characteristics can be prevented as much as possible. In particular, by using a material containing this metal as the main component as the bombardment electrode, the sputter rate is low, so that the inorganic layer Lb does not become too thick, and the bombardment treatment of the substrate 2 can be performed at the same time. The adhesion of the film formation layer to the substrate 2 is different between the case where one of the bombarded electrodes 1 and 1 is grounded as in the conventional case and the case where the bombarded electrode is not grounded as in the present embodiment. It turned out to be significantly different. In other words, when the bombard electrode 1 is grounded, a noticeable decrease in adhesion is observed even after 250 hours in the above-mentioned high-temperature and high-humidity test. It was found that there was no deterioration in the adhesion of the deposited layer even after 500 hours. This is because, when the bombardment electrode 1 is grounded, the grounded side of the bombardment electrode 1 and the grounded substrate 2 have the same potential, and a discharge occurs between the substrate 2 and the ungrounded side bombarded electrode 1. As a result, it is considered that the substrate 2 itself is damaged, the effective current between the bombard electrodes 1 and 1 is reduced, and the bombard process cannot be performed effectively. On the other hand, when the bombard electrodes 1 and 1 are not grounded, the potential of the grounded substrate 2 (almost 0 V) is applied to both the bombard electrodes 1 and 1.
1, the discharge is unlikely to occur between the substrate 2 and the bombarded electrodes 1 and 1, and there is no loss of power supply current. It is considered that the bombard processing is realized. The material of the bombardment electrode and the gas used for the bombardment treatment are not limited to those described above, and may be appropriately changed and implemented without departing from the gist of the present invention. As described in detail above, according to the method for manufacturing a magneto-optical recording element of the present invention, the bombard electrode is made of Ti transition metal, so that the bombard electrode component adheres to the substrate surface. Is suppressed, even if a bombard layer is formed between the substrate and a film forming layer such as a dielectric layer or a magnetic layer,
As a result, the electrical characteristics of the film-forming layer are not degraded, but rather, the adhesion between the substrate and the film-forming layer is improved, and a highly reliable magneto-optical recording element can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an internal schematic configuration diagram showing one embodiment of a bombard tank according to the present invention. FIG. 2 is a sectional view of a main part of the magneto-optical recording element. [Description of Signs] 1 ... Bombarded electrode 2 ... Substrate Lb ... Inorganic layer L1 ... First dielectric layer L2 ... Magnetic layer L3 ... Second dielectric layer L4 ... Reflective layer L5 Protective layer C Bombard tank

Claims (1)

(57) [Claim 1] A resin substrate and an electrode made of a non-grounded Ti transition metal are disposed in a chamber, and a gas introduced into the chamber by applying a voltage to the electrode is subjected to plasma. And bombarding one main surface of the substrate, and sequentially laminating at least a dielectric layer containing silicon nitride as a main component and a rare earth-transition metal magnetic layer on the one main surface of the bombarded substrate. A method for manufacturing a magneto-optical recording element, comprising: