JP2897879B2 - Sputtering method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for performing sputtering on a substrate such as a long body.

[Prior Art] The sputtering method is widely studied today and industrially used as a method for forming a thin film of a material such as a metal and a ceramic. For example, such a sputtering method is described in Kanehara's “Sputtering Phenomenon”, University of Tokyo Press (1984) and Asamaki, “Basics of Thin Film Preparation”, Nikkan Kogyo Shimbun, pages 125- (1977).

Usually, when a conductive material such as a metal is used as a target material, a DC sputtering method using a DC power supply is used. In order to increase the deposition rate, a magnetron sputtering method is generally used in which a magnet is arranged behind the target to concentrate plasma near the target surface.

However, conventionally, the sputtering method has been studied as a method of coating a thin film on the surface of a planar substrate, and the sputtering method for a substrate having a three-dimensional surface such as a round wire has not been sufficiently studied. .

Regarding sputtering of long objects, there are many examples of coating on a flat substrate such as a polymer film. Does not exist.

[Problems to be Solved by the Invention] In the conventional sputtering method and apparatus, with few exceptions, a substrate is arranged to face one target. In all cases, the target particles deposited on the substrate fly in a single direction or close to the substrate in all cases, so that a uniform coating can be applied to a long round wire such as a copper wire by sputtering. A device such as rotating the copper wire was required.

However, if a mechanism for rotating the substrate is provided, there is a problem that the device configuration becomes complicated, and especially when a long body is used as the base, such rotation cannot be practically used at all. .

Therefore, an object of the present invention is to solve such a problem and to provide a sputtering method and apparatus capable of applying a uniform coating to a long body such as a round wire.

[Means for Solving the Problems] In the sputtering method of the present invention, three or more targets each having a shield plate provided at an end portion are arranged in a ring shape with the target surfaces of the targets facing inward, and a shield is formed. The plate has a sufficient surface area to generate a stable discharge when a discharge voltage is applied between the plate and the target, and generates a plasma by applying a discharge voltage between the shield and the target. A substrate is introduced into a tube formed by a target, and the surface of the substrate is coated with a substance sputtered from the target by plasma.

Although the number of targets is not particularly limited as long as it is three or more, the number of targets is preferably four in consideration of both the configuration of the apparatus and the uniformity of coating.

Further, the substrate to which the present invention is applied is not limited to a long body, but when applied to sputtering of a long body, a particularly remarkable effect is exhibited. When the substrate is a long body, the long body is continuously introduced inside the ring formed by the target.

In addition, the sputtering apparatus of the present invention includes a plurality of three or more targets each having a shield plate provided at an end thereof so as to receive a substrate to be subjected to surface coating by sputtering inside the target surface of each of the targets. The shield plate and the target constitute a discharge electrode, and the shield plate has a sufficient surface area to generate a stable discharge when a discharge voltage is applied between the target and the shield plate. And characterized in that stable plasma for sputtering can be generated by the discharge.

[Operation] In the method of the present invention, since the target particles fly from three or more different directions with respect to the substrate, the coating can be uniformly applied around the substrate without rotating the substrate.

Further, in the present invention, when the base is a long body, the long body is continuously supplied and sputtering is performed, so that a uniform coating can be performed in the longitudinal direction of the base. The film thickness can be controlled by appropriately adjusting the supply speed of the substrate.

In order to uniformly coat the substrate, it is ideal to provide a cylindrical target, place the substrate at the center of the target, and sputter it. Since the respective areas of the surfaces are extremely different, it is difficult for normal discharge to occur, and it is difficult to arrange a magnet behind the target. Furthermore, it is difficult to produce such a cylindrical target.

According to the present invention, a plurality of targets each having a shield plate provided at an end thereof are arranged in an annular shape with the target surface facing inward, and plasma discharge is performed without using a cylindrical target. A substrate is introduced inside the ring and sputtering is performed on the substrate. Therefore, unlike the case where a cylindrical target is used, there is no significant difference in the area of the electrodes, and normal discharge can be performed. Further, it is easy to dispose the magnet on the target, and a readily available plate-like target can be used.

Embodiment FIG. 1 is a schematic sectional view showing an embodiment of the present invention. In FIG. 1, around a copper wire 4 as a base,
Four targets 1 are provided on all sides. A shield plate 2 is provided at each end of the target 1. One pole of the DC power supply 3 is connected to each target plate 1 and is negatively charged. Further, the positive pole side of the DC power supply 3 is connected to each shield plate 2,
Positively charged. Plasma discharge is performed between the target 1 and the shield plate 2.

By subjecting the four targets to annular arrangement and performing plasma discharge between the shield plate and the opposing shield plate, the target particles fly from four different directions with respect to the substrate. Forms a uniform coating film.

As described above, while forming a thin film on the copper wire 4 by sputtering, the copper wire 4 is moved in a direction perpendicular to the paper surface, and a thin film is sequentially formed in the longitudinal direction of the copper wire 4.

Using the sputtering device shown in FIG. 1, a wire diameter of 2 mm
Was coated with titanium metal to a thickness of about 3 μm. Five titanium-coated copper wire samples were prepared, and the diameter of each sample at 20 locations in the circumferential direction was measured with a laser micro gauge. Table 1 shows the measurement results. For comparison, the diameter of the copper wire as a substrate was measured at 20 points in the circumferential direction by a laser micro gauge in the same manner, and the results are shown in Table 1.

As is clear from Table 1, the variation in the diameter of the copper wire coated with titanium is almost the same as the variation in the diameter of the copper wire serving as the base, and it can be seen that the titanium is uniformly coated.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform coating by uniform sputtering, particularly on a substrate having a shape such as a round wire. In particular, since a long body can be continuously coated in the length direction, it is suitable for sputtering of a long body.

In addition, direct current (DC sputtering), alternating current (AC sputtering) and high frequency (RF
Sputtering) can be used, so that it can be applied to thin film coating of any target material.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the present invention. In the figure, 1 indicates a target, 2 indicates a shield plate, 3 indicates a DC power supply, and 4 indicates a copper wire as a base.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toru Kashiwagi 1-3-1 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Electric Industries, Ltd. Osaka Works (56) References JP-A-63-303065 (JP, A JP-A-61-250164 (JP, A) JP-B-61-51029 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 14/34-14/56

Claims (6)

(57) [Claims] A plurality of targets each having a shield plate provided at an end thereof are arranged in an annular shape with the target surface of the target facing inward, and a discharge voltage is applied between the shield plate and the target. Has a surface area sufficient to generate a stable discharge when is applied, generates a plasma by applying a discharge voltage between the shield and the target, and forms a tube formed by the plurality of targets. A sputtering method, wherein a substrate is introduced inside the substrate, and a surface of the substrate is coated with a substance sputtered from the target by the plasma. 2. The sputtering method according to claim 1, wherein the number of said targets is four. 3. The sputtering method according to claim 1, wherein said substrate is a round wire. 4. The sputtering method according to claim 1, wherein the substrate is a long body, and the long body is continuously introduced into a tube formed by the target. 5. A plurality of three or more targets each having a shield plate provided at an end thereof so as to receive a substrate to be subjected to surface coating by sputtering inside the substrate with the target surface of the target facing inward. The shield plate and the target constitute a discharge electrode, and the shield plate has a surface area sufficient to generate a stable discharge when a discharge voltage is applied between the shield plate and the target. A sputtering apparatus characterized in that stable plasma for sputtering can be generated by the discharge. 6. The sputtering apparatus according to claim 5, wherein the number of said targets is four.