JPS6176673A - sputtering method - Google Patents

Abstract

PURPOSE:To diminish the space between a target and substrate and to obtain a uniform film thickness by forming the shape of magnetic pole surface of the magnet disposed on the rear of the target into a rectangular shape and making the target position movable relative to the target surface. CONSTITUTION:The target 7 is supported by a cathode part 5 and the substrate 6 is held by a supporting frame 8 to provide an anode part in a vacuum vessel 1. The magnet 4 having the rectangular-shaped magnetic pole surface is disposed to the rear of the target 7 in parallel with the target surface. The magnet supporting part 11 is slid in the arrow direction by a driving part 12 on the outside of the device. The part to be sputtered of the target 7 is thereby moved successively from the end to the end of the target 7, by which the consumption of the target 7 is made uniform over the entire part and the space between the target 7 and the substrate 6 is made substantially small.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a sputtering method for depositing a thin film such as a metal film or oxide film onto a substrate on a counter electrode by physical means.
In particular, it relates to improvements in sputtering methods using magnets.

[Conventional technology]

Chemical methods and physical methods are used to form thin films, but the physical method (PVD method) in particular evaporates the same material as the thin film to be produced in vacuum or gas. This is a technique for attaching it to a substrate on a counter electrode, and is mainly used as a method for forming single metal or alloy films.

The PVD method includes a vacuum evaporation method and a sputtering method, and the vacuum evaporation method evaporates the deposition source material by heating it.
On the other hand, the sputtering method is a method in which ions such as argon gas are bombarded with the target, which is an evaporation source, and the atoms of the target fly out to the outside and are attached to the substrate on the opposing electrode. be.

In the sputtering method, magnetron-type sputtering equipment is widely used, which applies a magnetic field parallel to the surface of the target and confines plasma near the target by the action of orthogonal electromagnetic fields, thereby increasing the generation of argon ions.

First, FIG. 2 shows a schematic diagram of a sputtering apparatus using a conventional method. A cathode part 5 supports a target 7, and a magnet 4 is provided on the back surface of the cathode part 5 to generate a magnetic field parallel to the target surface. A substrate 6 such as a wafer is held by a support frame 8 provided opposite to a target 7 to constitute an anode section. The entire configuration is housed in a vacuum chamber 1,
The vacuum chamber is provided with an exhaust port 2 and a gas inlet port 3.

When a direct current or high frequency voltage of 10 is applied between the anode and the cathode, the electrons undergo cycloidal motion due to the action of the orthogonal electromagnetic field, which increases the density of plasma on the target surface to increase the generation of argon ions, increasing the sorrel-vine efficiency. improves. As described above, the magnetron sputtering method is an extremely effective deposition method.

[Problem that the invention seeks to solve]

As mentioned above, the sputtering method is an extremely effective vapor deposition method, but in order to improve the distribution of the vapor deposited film, it is necessary to widen the distance between the target and the wafer, which causes a reduction in the span rate. In addition, in order to improve the sputter coverage (coating of the film on the step part) distribution, it is necessary to make the erosion area (erosion area due to sputtering on the target surface) larger than the outer circumferential dimension of the wafer, and the diameter of the target part should be larger than the wafer diameter. It requires about twice the size. Therefore, the capacity of the applied power source also increases, and the amount of heat generated also increases. Further, as shown in the cross-sectional view of FIG. 3, there are also drawbacks such as non-uniform consumption of the target.

In order to improve the productivity of semiconductors, wafer sizes tend to become larger and larger, and the disadvantages of conventional sputtering methods for such large-area wafers are unavoidable. .

In order to solve this problem, methods of moving the magnet or target have already been proposed in Japanese Patent Laid-Open Nos. 53-47384 and 1982-14853. The former is even if the target is movable relative to the cathode;
The latter is improved by rotating a magnet placed eccentrically with respect to the central axis of the target.

The present invention has further improved sputtering characteristics 5 to reduce target consumption and power supply capacity than these methods.

[Means for solving problems]

In order to solve the above problems, the present invention makes the shape of the magnetic pole surface of the magnet placed on the back surface of the target rectangular, and at the same time, the magnet position is parallel to the target surface and the length direction of the magnet is A feature of this method is that by adding a mechanism for moving in different directions, the target portion to be sputtered is sequentially moved from one end of the target to the other.

[For production]

In the present invention, the shape of the magnetic pole surface of the magnet placed on the back surface of the target is rectangular, and at the same time, by adding a mechanism that allows the magnet position to be moved parallel to the target surface, the distance between the target and the substrate is sufficiently small. It is also possible to easily obtain a uniform film thickness, and the formation rate of the deposited film does not decrease on a substrate with a larger area than before.

In addition, the lengthwise dimension of the target magnet needs to be approximately twice the diameter of the wafer in order to improve step coverage, but since the width of the magnetic poles is small, the erosion area is small and the load impedance to the power supply is reduced. It has the advantage that it can be made large and the power supply capacity can be small.

〔Example〕

An embodiment of the present invention is shown in FIG. 1(a) below. A cathode section 5 supports a target 7, and a magnet 4 is provided on the back surface of the cathode section 5 to generate a magnetic field parallel to the target surface. A substrate 6 such as a wafer is a target 7
The anode portion is held by a support frame 8 provided opposite to the anode portion. The shape of the target may be any shape, such as a rectangle or a circle, as long as it is sufficiently larger than the wafer size.

The entire configuration is housed in a vacuum chamber 1, and the vacuum chamber has an exhaust port 2.
and a gas inlet 3 are provided. A direct current or high frequency voltage 10 is applied between the anode and the cathode.

The shape of the magnetic pole surface of the magnet 4 is rectangular, and in this figure, the long axis is perpendicular to the plane of the drawing, and by rotating the drive section 12 outside the device, the magnet support section 11 slides in the direction of the arrow. The state of movement of the magnet relative to the target surface is shown in a plan view in FIG. 1(b). A support stand 13 is provided to help the magnet slide smoothly. Although the drive unit is shown in the simplest structure in this figure, automation with a control mechanism is easily possible.

〔Effect of the invention〕

In the present invention, the wet carbon on the magnetic pole surface of the magnet placed on the back surface of the target is rectangular, and at the same time, a mechanism is added that allows the magnet position to be moved parallel to the target throat surface, thereby reducing the distance between the target and the substrate. It can be made sufficiently small and the sputtering rate can be increased. In addition, because the instantaneous erosion area is small, the power supply capacity is small, so the heat generation at the target is also small, and there is less need to consider cooling.Also, target wear is reduced over the entire target surface as shown in Figure 4. It is uniform and contributes to improving target usage efficiency.

[Brief explanation of the drawing]

FIG. 1(a) shows a cross-sectional view of the entire configuration of the device used to carry out the present invention, and FIG. A magnetron sputtering apparatus according to the present invention is shown, and the wear of the target in this case is shown in the third concave plan view. Fig. 4 is a sectional view showing the state of wear of the target according to the present invention. In the drawing, 1 is a vacuum chamber; 2 is an exhaust port, 3 is a gas inlet, 4 is a magnet, 5 is a cathode, 6 is a wafer substrate, 7
is the target, 8 is the support frame, 9 is the insulator, 10 is the power source,
11 is a magnet support part. 12 is the drive part, 13 is the magnetic drive support block. Figure (0) Brown Figure (b) Second eye O

Claims (1)

[Claims] In the method of generating sputtering from the target surface by generating an electromagnetic field on the target surface, a magnet with a rectangular magnetic pole face is used as the magnetic field generating means placed on the back side of the target, and this magnet is oriented in a direction different from its length direction. A sputtering method characterized by sequentially moving a target portion to be sputtered from one end of the target to the other end by moving the target.