JPH0834347B2 - Method for manufacturing oxide substrate coated with metal thin film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an oxide substrate coated with a metal thin film (hereinafter simply referred to as a substrate), and more particularly to a method for manufacturing an electric circuit substrate having an intermediate layer.

(Prior Art) Conventionally, a substrate having a metal thin film formed thereon has been used as a substrate for various circuits and sensors. In order to manufacture this substrate, a metal thin film is formed by a sputtering method, a vapor deposition method or the like, but there is a drawback that the metal thin film has insufficient adhesion to the substrate and the metal thin film is easily peeled off.

It is considered that this is because the affinity between copper and the oxide, which is the main component of the substrate, is small, but the substrate on which the metal thin film is formed is continuously subjected to treatment such as ultrasonic cleaning in which peeling easily occurs. There is a possibility that a defective product may be produced in the manufactured product, and further, if it is peeled off after being incorporated into a circuit, it will naturally lead to failure of an electronic device including the circuit, and the disadvantage thereof will be great.

(Object of the Invention) An object of the present invention is to solve the drawbacks of the prior art and to provide a method for producing a substrate on which a metal thin film is firmly adhered and formed.

(Means for Solving the Problems) The present invention provides a substrate coated with a metal thin film, which comprises forming an intermediate layer containing molybdenum and silicon on the surface of the substrate and then forming a metal thin film on the intermediate layer. Is the way.

 The present invention will be described in detail below.

In the present invention, the reason why the metal thin film is firmly adhered and formed on the substrate by forming the intermediate layer containing molybdenum and silicon is that silicon shares an oxide which is the main component of the substrate and oxygen of the oxide. It is speculated that this is because a large adhesion force is generated between the two.

For example, even if a layer containing only molybdenum is formed between the metal thin film and the substrate as the intermediate layer, the adhesion is improved as compared with the case where the intermediate layer is not present, but it is still peel-resistant when used as a circuit board or the like. Is hard to say.

As the substrate in the present invention, a substrate containing silicon dioxide as a main component which has been conventionally used for a circuit can be used without limitation.

Most preferably, molybdenum and silicon that form the intermediate layer are in the form of an alloy, but in addition to this, a mixture of a large number of fine particles may be used. The ratio of the two is
It is most preferable that the atomic ratio of silicon to molybdenum is 1.5 to 2.5, and in this range, the adhesion between the metal thin film and the substrate is almost constant. Of course, a mixture of the both having a ratio outside this range may be used, and in this case also, it is necessary to use an amount of silicon which gives sufficient adhesion to the oxide in the substrate.

The thickness of the intermediate layer containing molybdenum and silicon is 10
It is desirable to set it between Å and 1μ. If it is less than 10Å, sufficient adhesion cannot be given between the metal thin film and the substrate to prevent peeling, and if it exceeds 1μ, it is not economical. This will have a non-negligible effect on the transmission characteristics of the high frequency circuit.

The method of forming this intermediate layer on the substrate is not particularly limited, and a known method such as a conventional sputtering method or vapor deposition method can be employed.

Next, a metal thin film is formed on this intermediate layer. This metal thin film can be formed by a conventional method as in the case of forming the intermediate layer. However, in order to improve work efficiency, the intermediate layer formation and the metal thin film formation are performed. It is preferable that the targets of molybdenum and silicon and the target of metal are mounted in the same sputtering apparatus and the like so as to be continuously performed.

The thickness of the intermediate layer and the metal thin film can be set to an arbitrary thickness according to the application by changing the applied voltage and the like during the processing time.

Examples of the present invention will be described below, but the examples do not limit the present invention.

(Example) A quartz substrate was washed with water and methyl alcohol and dried, and then molybdenum-silicon (MoS) was used as a first target.
i ₂ ), and copper was set as a second target at a predetermined position in the sputtering apparatus in which copper was set. Then, the inside of the sputtering apparatus was evacuated using a vacuum pump to a vacuum degree of 5 × 10 ⁻⁵ torr, and then the quartz substrate was plasma-etched for 10 minutes in an argon gas of 5 × 10 ⁻³ torr. Subsequently, the first target MoSi ₂ was subjected to high frequency sputtering at 1 kw for 15 seconds, and then the second target copper was subjected to DC 600 V, 5 A for 10 minutes. After cooling in the apparatus for 20 minutes, the quartz substrate was taken out from the sputtering apparatus. The quartz substrate had a copper layer thickness of 1 μm and a MoSi ₂ layer thickness of 20 Å.

Next, the quartz substrate was ultrasonically cleaned in pure water under the conditions of a frequency of 28 kHz and 500 W and the peeling was observed. No peeling occurred.

Similarly, when another thickness of MoSi ₂ was prepared and the ultrasonic peeling test was performed, the effect of the MoSi ₂ layer appeared at 5 Å and the peeling of the metal thin film did not occur.

On the other hand, the metal thin film on the quartz substrate on which the MoSi ₂ intermediate layer was not formed was easily peeled off by ultrasonic cleaning.

Further, when the value of X of MoSi _X was changed in the range of 1.5 to 2.5 and the same peeling test was conducted, the adhesion strength did not change.

Although copper was used for the metal thin film in the above-mentioned embodiment, the present invention is not limited to this. Further, although quartz is used for the substrate in the above-mentioned embodiment, the present invention is not limited to this, and any material made of various oxides such as glass and ceramics may be used.

(Effects of the Invention) The present invention forms an intermediate layer containing molybdenum and silicon having a high affinity for silicon dioxide, which is the main component of the substrate, between the substrate and the metal thin film to be bonded thereto, and Is coated with a metal thin film. Therefore, in the prior art, since the substrate and the metal thin film having a small affinity for each other were bonded without interposing the intermediate layer, the peeling occurred, whereas in the present invention, the strong adhesion of the silicon present in the intermediate layer to the substrate. The thin metal film can be firmly adhered and formed on the substrate due to its property, and it can be reliably prevented from peeling off during subsequent processing or after being incorporated into a circuit, and manufacturing of defective products due to peeling of the metal thin film can be avoided. This ensures stable long-term use of electronic equipment incorporating the substrate.

Claims (6)

[Claims] 1. A method for producing a substrate coated with a metal thin film, which comprises forming an intermediate layer containing molybdenum and silicon on the surface of a substrate made of an oxide, and then forming a metal thin film on the intermediate layer. 2. The manufacturing method according to claim 1, wherein the average thickness of the intermediate layer is in the range of 10Å to 1 μm. 3. The atomic ratio of silicon to molybdenum is 1.5.
The manufacturing method in any one of Claim 1 or 2 which exists in the range of -2.5. 4. The method according to any one of claims 1 to 3, wherein the intermediate layer is formed by at least one of a sputtering method and a vapor deposition method. 5. The manufacturing method according to claim 1, wherein the metal thin film is formed by at least one of sputtering and vapor deposition. 6. The manufacturing method according to claim 1, wherein the formation of the intermediate layer and the formation of the metal thin film are performed in the same apparatus.