JPS61295368A - Cathode for magnetron sputtering - Google Patents

Abstract

PURPOSE:To improve by simple mechanism the use efficiency of a square-shaped target by making adjustable the inclination, to the target surface, of a magnetic- field generating device provided at the rear of the target surface of a cathode. CONSTITUTION:The magnetic-field generating device 15 is provided at the rear of the reverse side 13 of the target 51 surface of the cathode 11. The device 15 is made turnable, for example, by means of a turning axis 17 and resultingly the angle formed by a straight line joining the north and south poles and by the target 51 surface is made variable, so that a practically square- shaped closed loop constituted of a line 19 of magnetic force starting from the north pole of the above device 15, passing through the target 51 surface and terminating in the south pole and of the target 51 surface can be formed on the surface of the target 51.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode used in a magnetron sputtering apparatus.

[6] In the conventional sputtering method, the slow film formation rate and the large temperature rise of the substrate were major problems, but these problems could be solved by applying a magnetic field perpendicular to the electric field. A significant improvement was achieved by sputtering. In particular, the target electrode (cathode)
N and S poles are arranged spaced apart from each other on the back side of the.

The magnetron sputtering method, which generates a closed magnetic field on the target surface to confine the plasma, can achieve a high deposition rate and can also suppress the inflow of electrons into the substrate (December 10, 1982) , published by Ohmsha, thin film handbook p186-190).

However, in the magnetron sputtering method, since sputtering occurs at the highest speed in a portion where the direction of the electric field and the direction of the magnetic field are perpendicular to each other, there is a problem that the target in this portion is locally eroded. When localized erosion occurs, the efficiency of target use deteriorates. Conventionally, it has been proposed to provide a magnetic field generating device sufficiently smaller than the target on the back surface of the target and move it parallel to the target, thereby moving in a closed loop and using the target uniformly. However, this method has the problem that the entire surface of the target is not always used for sputtering and the braking mechanism becomes complicated.

On the other hand, large rectangular targets such as 5 inches x 15 inches and 5 inches x 20 inches are now commonly used as production targets, and as targets are becoming larger, There is a growing demand for improved usage efficiency.

SUMMARY OF THE INVENTION The present invention aims to improve the efficiency of using a rectangular target with a simple mechanism.

In the magnetron sputtering cathode of the present invention, a magnetic field generator is disposed on the back side of the target surface of the cathode, and a magnetic field is emitted from the north pole of the magnetic field generator, passes through the target surface, and enters the south pole. In a sputtering device in which a substantially rectangular closed loop is formed on the target surface by lines of magnetic force and the target surface, the angle between the straight line connecting the N pole and the S pole of the magnetic field generator and the target surface is It is characterized in that the magnetic field generating device is attached so as to be variable.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view schematically showing an embodiment of the cathode of the present invention, and a target 51 is disposed on the target surface 13 of the cathode 11 for sputtering. cathode 1
A magnetic field generator 15 is provided on the opposite side of the first target surface 13 .

The cathode 11 is placed electrically floating from the vacuum chamber 31 via an insulator 33, and is connected to a sputtering power source 41.

As shown in FIG. 2, the magnetic field generator 15 is constructed by arranging permanent magnet pieces 21a, 21b, and 23 in a rectangular shape so that their N and S poles are spaced apart from each other. Further, it is disposed so as to be able to rotate once by a rotation shaft 17 provided in the longitudinal direction, so that the angle with respect to the target surface 13 can be adjusted.

FIG. 3A is an explanatory diagram showing the relationship between the target 51 and the magnetic field generator 15, and the magnetic field H and the electric field E are orthogonal to each other at a location Ao. 19 indicates lines of magnetic force. Electric field E and magnetic field H
Since the sputtering speed is higher at the point where these are orthogonal to each other, the corresponding portion B0 of the target 51 is sputtered to a greater extent. Therefore, if sputtering is continued in this state, only the 86th part will be locally scraped and two lotions will be generated.
As shown in Figure C, the magnetic field generator 15 can be rotated to change its angle with respect to the target 51. Third
In diagram B, as a result of tilting the magnetic field generator 15, the point where the electric field E and the magnetic field H intersect at right angles has moved to A1. Therefore, the part B of the target 51 is sputtered at a high speed. The same applies to the case shown in FIG. 3C, where B2 of the target 51 is largely shaved off at the center of the portion corresponding to A2.

In this manner, by rotating the magnetic field generating device 51 continuously or intermittently as sputtering progresses, it is possible to move the position where large scraping can be made in the lateral direction of the target.

At the location indicated by 25 in FIG. 2, the orthogonal positions of the electric field E and the magnetic field H do not change even with one rotation.Therefore, as the magnet pieces 21b arranged in the transverse direction, the magnet pieces 21a are arranged in the longitudinal direction. By using a magnet with a weak magnetic field and reducing the sputtering speed in this area, it is possible to achieve even more uniformity of the two lotions. In the above embodiments, a mechanism for changing the angle using a rotating shaft provided in the longitudinal direction of the magnetic field generator has been described, but the angle adjusting means is not limited to this, and any appropriate method can be used.

Advantageous Effects According to the present invention, by making the inclination of the magnetic field generator with respect to the target surface adjustable, the erosion of the target can be made uniform with a simple configuration, and the efficiency of use of the target is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a cathode for magnetron sputtering according to the present invention. FIG. 2 is a perspective view showing a magnetic field generating device used in the present invention. FIG. 3A, FIG. 3B, and FIG. 3C are explanatory diagrams showing the relationship between the target and the magnetic field generator. 11...Cathode 13...Target surface 15...Magnetic field generator 17...Rotation shaft 21a, 21b, 23...Magnet piece 51...Target patent applicant Shinku Kikai Kogyo Co., Ltd. Company eraser 1 diagram

Claims (1)

[Claims] 1. A magnetic field generator is disposed on the back side of the target surface of the cathode, and a substantially rectangular closed loop is formed between the target surface and the lines of magnetic force that emanate from the N pole of the magnetic field generator, pass through the target surface, and enter the S pole. In a sputtering device designed to form a sputter on a target surface, the N of the magnetic field generating device is
A cathode for magnetron sputtering, characterized in that the magnetic field generating device is arranged so that the angle between the straight line connecting the pole and the south pole and the target surface is variable.