KR20040044995A - Method and apparatus for sputter deposition of epilayers with high deposition rate - Google Patents

Abstract

The present invention relates to sputter deposition of epilayers using a plurality of magnetrons 2 and 4 having different shapes, such as flat plate 2 and ring 4.

Description

TECHNICAL AND APPARATUS FOR SPUTTER DEPOSITION OF EPILAYERS WITH HIGH DEPOSITION RATE}

Radio frequency (RF) magnetron sputtering techniques are widely used for sputtering thin films. However, in the case of a thick film (ie, a film having a thickness of 1 µm or more), alternating current (AC) magnetron sputtering is advantageous because the deposition rate is high.

In US Pat. Nos. 5,814,195 and 6,356,010, the sputtering method is described using an AC power source. In each example, a plurality of magnetrons such as cylindrical magnetrons are used, but sputtering is only present on the surface of the magnetron.

In sputtering processes in which a plurality of magnetrons are adopted, it has been found to be advantageous to use at least one magnetron in a ring shape. Films deposited by such a process will be less contaminated.

This application claims the benefit of US Provisional Application No. 60 / 325,331, filed September 27, 2001, which is incorporated in its entirety as part of this specification.

The present invention relates to sputter deposition of epilayers using a plurality of magnetrons having different shapes.

1 is a schematic diagram of elements of a sputtering apparatus.

One embodiment of the present invention is a film deposition apparatus having a first magnetron target and a ring-shaped second magnetron target in a sputtering chamber, and a film deposition method employing such a device.

Another embodiment of the present invention provides a film deposition apparatus having a first magnetron target in a sputtering chamber, a second magnetron target having a hole providing an outer surface and an inner surface on which the target material can be sputtered, and a film deposition employing such a device. It is a way.

Another embodiment of the present invention is a method of depositing a film by sputtering from a plurality of magnetron targets in a sputtering chamber, wherein the negative potential is periodically shifted to a ring-shaped magnetron target.

Yet another embodiment of the present invention is a method of depositing a film by sputtering from a plurality of magnetron targets in a sputtering chamber, wherein the negative potential is periodically displaced to a magnetron target having a hole providing an outer surface and an inner surface on which the target material can be sputtered. This is the step.

In the present invention, methods and apparatus are provided for epitaxial sputter deposition of films on substrates, especially thick epilayers, at high deposition rates. It is preferred to deposit epitaxial films by using AC magnetron sputtering techniques.

Sputter epitaxy chambers for sputtering target materials, such as nonconductive materials, include a plurality of magnetron sputtering targets as a source of sputter material. The target may have a different shape, such as a plate or ring. A good property of the ring magnetron is that the target material has a hole that provides an outer surface and an inner surface where it can be sputtered. The ring magnetron does not have to be a perfect circle. As long as the hole is present, it can be formed essentially into any shape suitable for the sputtering chamber, such as a perfect circle, incomplete circle, ellipse or polyhedron. There is no limit to the dimensional size change that the ring magnetron can take along all three axes provided to function as the magnetron.

The AC power source is connected to the first and second magnetron targets in the sputtering chamber and one of the magnetron targets is a ring magnetron. The ring magnetron may be disposed between the substrate and another magnetron target, such as a planar, rectangular magnetron without any holes. The ring magnetron may be constructed from the same material as another target or from only one or only a few of the materials from which other targets can be made. During the deposition process, the first and second targets are ring magnetrons, one of which is periodically operated as a cathode and an anode. Sputtering from the magnetron target and the ring-shaped target together form a film on the substrate.

The sputter epitaxy chamber for sputtering nonconductive material comprises two magnetron sputtering sources, at least one formed as a ring and a substrate. Instead of having two planar, rectangular magnetron sputtering sources and connecting an AC power source between them, we propose in the present invention a plurality of magnetron sputtering sources, one of which is ring-shaped. This magnetron is constructed from the same material as the other target or from one of the elements that complements the other target if it is a composite of multiple elements. During the deposition process, both targets operate periodically as a cathode and an anode. The use of AC power generates a negative potential to periodically displace from one magnetron to another. When the negative potential is displaced into the ring magnetron, the material is sputtered onto the substrate from the deposition target. Thus, the film on the substrate is sputtered from both the first and second magnetrons, one of which is a ring magnetron. If AC is used by connecting one electrode to the magnetron and grounding one electrode, this reduces the deposition of contaminants on the film that may occur.

Elements of a sputter epitaxy chamber comprising a first magnetron sputtering source 2, a ring-shaped magnetron sputtering source 4 and a substrate 6 are shown in FIG. 1. The AC power source 8 is connected to two magnetrons. The ring magnetron is disposed between the first target and the substrate. The ring magnetron is constructed from the same material as the first magnetron, or from only one or several of the elements that supplement the first target if the first target is a composite of multiple elements.

During the deposition process, the first target and the ring target periodically operate as a cathode and an anode. The presence of the ring-shaped target helps to reduce contamination of the sputtered epitaxial film when the first magnetron target has a positive voltage. Sputtering from both magnetron targets forms a film on the substrate. Since deposition of thick films requires longer sputtering cycles, the ring magnetron target can be equipped with a cooling device such as a water jacket.

Claims (12)

A film deposition apparatus comprising a first magnetron target and a second magnetron target in a sputtering chamber, the second magnetron target having holes providing an outer surface and an inner surface on which the target material can be sputtered. The film deposition apparatus of claim 1, wherein the second target is basically a perfect circular shape. The film deposition apparatus of claim 1, wherein the second target is positioned between the substrate on which the film is deposited and the first target. The film deposition apparatus of claim 1, wherein the second target has a negative potential. The film deposition apparatus of claim 1, wherein the sputter deposition is powered by an alternating current. The film deposition apparatus of claim 1, wherein the first and second targets are made of the same material or different materials. The film deposition apparatus of claim 1, wherein the second target is cooled. A film deposition apparatus according to claim 1, wherein the film is a thick film. A film deposition apparatus comprising a first magnetron target and a second magnetron target in a sputtering chamber, wherein the second magnetron target is ring-shaped. A method of depositing a film by sputtering from a plurality of magnetron targets in a sputtering chamber, Periodically displacing the negative potential on the magnetron target having holes providing the outer and inner surfaces to which the target material can be sputtered. A method of depositing a film by sputtering from a plurality of magnetron targets in a sputtering chamber, Periodically displacing the negative potential on the ring-shaped magnetron target. 10. A film deposition method comprising sputtering the film with the apparatus of any one of claims 1-9.