JPS61221363A - Sputtering apparatus - Google Patents

Abstract

PURPOSE:To improve the quality of a film formed on a substrate by placing a substrate side magnet as well as a target side magnet so as to increase the uniformity of sputtering from the surface of a target and the rate of sputtering. CONSTITUTION:A magnet 11 is placed behind a substrate 6 in a sputtering apparatus. The magnet 11 generates a magnetic field on the surface of the substrate 6 parallel to the surface of a target 7 in the plasma generating region between the target 7 and the substrate 6. The direction of the magnetic field coincides with the direction of a magnetic field generated by a cathode 5 side magnet 4. The substrate side magnet 11 may be similar in shape and structure to the target side magnet 4.

Description

Detailed Description of the Invention [Summary] The present invention is particularly applicable to a magnetron type sputtering apparatus which is widely used as a thin film forming apparatus using the PVD method (physical vapor deposition method). It is also placed on the side to prevent damage to the substrate, expand the target erosion area, and improve film quality.
We aimed to improve the sputtering rate.

[Industrial application field]

The present invention relates to a sputtering apparatus for depositing a thin film such as a metal film or an alloy film onto a substrate on a counter electrode by physical means, and particularly to an improvement in a magnetron type sputtering apparatus using a magnet.

Magnetron sputtering equipment places a target made of the same material as the thin film to be produced in a gas, and bombards the target with ions such as argon gas, causing the atoms of the target to fly out and adhere to the substrate on the counter electrode. It is mainly used as a forming device for single metals, alloy films, etc.

The structure of the sputtering equipment is magnetron type sputtering, in which a magnetic field is applied parallel to the surface of the target, and plasma is confined near the target by the action of an orthogonal electromagnetic field created by the electric field between the target and the substrate, increasing the generation of argon ions. The device is widely used.

When using this device, there is a need for an improved sputtering device that can prevent the substrate from being damaged by ion bombardment and provide a uniform film quality with high efficiency.

[Conventional technology]

An outline of a conventionally widely used magnetron type sputtering apparatus will be explained with reference to FIG.

The work area is housed in a vacuum chamber 1, and the vacuum chamber is provided with an exhaust port 2 and a gas inlet port 3. 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 held by a support frame 8 provided opposite to a target 7 to constitute an anode section.

A negative voltage is applied between the anode and the cathode by a DC power supply 10 as shown in the figure.

Due to the magnetic field of the magnet and the orthogonal electromagnetic field action generated on the target surface by the applied DC power, the electrons perform cycloidal motion, increasing the order of argon ions,
The plasma density on the target surface increases, improving sputtering efficiency.

As described above, the magnetron sputtering apparatus is widely used as an extremely effective method for vapor deposition of metals or alloys.

[Problem that the invention seeks to solve]

With the above-mentioned conventional equipment, there are problems such as non-uniform deposition due to the fact that the magnetic field on the target surface is not necessarily uniform, and problems such as electrons or argon ions colliding with the substrate and causing damage. also occurs.

Therefore, in order to improve the distribution of the deposited film and reduce damage, it is necessary to increase the distance between the target and the substrate, which on the other hand leads to a decrease in the sputtering rate.

In addition, in order to improve the step coverage (thin film coverage at stepped portions), it is necessary to have an erosion area (corrosion area due to sputtering on the target surface) larger than the outer circumference of the substrate, and the capacity of the applied power source must also be increased. There are problems such as increased size and increased heat generation.

[Means for solving problems]

The above problem is solved by installing a magnet on the substrate side that generates a magnetic field in the same direction as the magnetic field generated on a plane parallel to the target by the magnet on the cathode side in the plasma generation region sandwiched between the target and the substrate. This is significantly reduced by the magnetron type sputtering apparatus of the present invention.

[Effect]

Due to the substrate-side magnet according to the present invention, the magnetic field line distribution on the target surface has a squashed shape and is more parallel to the target than the conventional structure.

This increases the uniformity of the magnetic field distribution on the target surface, widens the erosion area, and improves the quality of the film grown on the substrate.

〔Example〕

An embodiment of the present invention will be explained in detail with reference to FIG.

Description of the same reference numerals used in the prior art section will be omitted.

The difference from FIG. 2 is that another magnet 11 is also installed on the board side. The shape of the magnet may have a structure similar to that of the magnet on the target side.

The direction of the magnetic field is in the plasma generation region between the substrate and the target, and the two magnets are arranged so that the directions of the magnetic fields are in the same direction on a plane parallel to the target.

In other words, the magnetic poles of the respective magnets are arranged so as to face each other.

By adopting such a structure, the magnetic field line distribution becomes a crushed shape due to mutual repulsion, and changes from the conventional chevron shape to a shape close to parallel to the target surface. This is the first
This can be understood from the magnetic field line distribution shown in Fig. 2.

As a result, the plasma generation density on the target surface increases, and the uniformity of the plasma on the target surface also increases.

〔Effect of the invention〕

As explained above, the structure of the sputtering equipment in which the magnet according to the present invention is also installed on the substrate side increases the uniformity of sputtering from the target surface and the sputtering speed, which contributes to improving the film quality of the laminated thin film on the substrate. It is important to do so.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a magnetron sputtering device according to the present invention, and FIG. 2 is a conventional magnetron sputtering device. 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 substrate, 7 is a target, 8 is a support frame, 9 is an insulator, 10 is a power source, 11 are the magnets of the present invention, respectively.

Claims (1)

[Claims] In the plasma generation region sandwiched between the target (7) and the substrate (6), a magnetic field in the same direction as the magnetic field by the magnet (4) on the cathode side is applied on a plane parallel to the target surface. A sputtering apparatus characterized in that a magnet (11) for generating electricity is also installed on the substrate side.