Method for pretreating substrates for PVD methods
The invention relates to a method for coating work pieces in a vacuum treatment system having a first electrode embodied as a target, which is part of an arc vaporization source. Using the first electrode, an arc is operated with an arc current and vaporizes material. A bias voltage is applied to a bias electrode, which includes a second electrode that is embodied as a work piece holder, together with the work pieces. Metal ion bombardment is carried out either to pretreat the work pieces or in at least one transition from one layer to an adjacent layer of a multilayer system, so that neither a significant material removal nor a significant material buildup occurs, but instead, introduces metal ions into a substrate surface or into a layer of a multilayer system.
1. A method for coating work pieces in a vacuum treatment system having a first electrode embodied as a target, which is part of an arc vaporization source, comprising:
using the first electrode, operating an arc at a first arc source in a pulsed fashion with an arc current, and vaporizing material from the target; applying a bias voltage from a first bipolar power supply to a bias electrode, wherein the bias electrode comprises a second electrode that is embodied as a work piece holder, together with the work pieces, and operating a second bipolar power supply between the first arc source and a second arc source, wherein the first and second bipolar power supplies are operated in pre-ionized plasma of the first and second arc sources, respectively, and the bipolar power supply between the first and second arc sources, which are separately operated by respective DC power supplies, is operated in such a manner that a current rise of at least 1,000 A/ms is produced, which results in an increase of a substrate ion current;
pretreating the work pieces using metal ion bombardment, which includes increasing the substrate ion current without a significant increase of a vaporizing rate by using a bias voltage of not larger than 800 V, and controlling the bias voltage to achieve equilibrium between layer deposition and etching so that neither a significant material removal nor a significant material buildup occurs, but instead, introducing metal ions into a substrate surface, with the introduced metal ions including ions of a metal that is a component of a layer to be applied; and
directly depositing the layer onto the pretreated substrate surface.
2. The method as recited in claim 1 , wherein the layer comprises at least one of the group consisting of a carbide layer, an oxide layer, and a nitride layer.
3. The method as recited in claim 1 , wherein the layer has one or more metallic components.
4. The method as recited in claim 3 , wherein the layer comprises at least one of the group consisting of Ti, Al, B, Si, TiAl, and AlCr.
5. The method as recited in claim 1 , wherein the layer is a layer of titanium nitride, titanium carbon nitride, titanium aluminum nitride, aluminum oxide, aluminum chromium oxide, boron nitride, or silicon nitride.
6. The method as recited in claim 1 , wherein the introduced metal ions are a metallic component of the layer to be deposited onto the substrate surface or the metallic component of the next layer of a multilayer system.
7. The method as recited in claim 1 , comprising letting reactive gas containing oxygen into the vacuum treatment system during the pretreatment.
8. The method as recited in claim 1 , comprising using targets for the pretreatment, wherein the targets are composed of materials that are also used to synthesize an oxide layer.
9. The method as recited in claim 1 , comprising using an alloy target for the pretreatment.
10. The method as recited in claim 1 , comprising selecting the bias voltage to ensure that the layer has a high density and stress resulting from acceleration of the ions toward the substrate.
11. The method as recited in claim 1 , comprising eliminating a working gas and carrying out the method in only a reactive gas.
12. A method for producing a multilayer system on a work piece in a vacuum treatment system having a first electrode embodied as a target, which is part of an arc vaporization source, comprising:
using the first electrode, operating an arc at a first arc source in a pulsed fashion with an arc current and vaporizing material from the target, and applying a bias voltage from a first bipolar power supply to a bias electrode, wherein the bias electrode comprises a second electrode that is embodied as a work piece holder, together with the work pieces, and operating a second bipolar power supply between the first arc source and a second arc source, wherein the first and second bipolar power supplies are operated in pre-ionized plasma of the first and second arc sources, respectively, and the bipolar power supply between the first and second arc sources, which are separately operated by respective DC power supplies, is operated in such a manner that a current rise of at least 1,000 A/ms is produced, which results in an increase of a substrate ion current;
carrying out a metal ion bombardment in at least one transition from one layer to an adjacent layer of the multilayer system, which includes increasing the substrate ion current without a significant increase of a vaporizing rate by using a bias voltage of not larger than 800 V, and controlling the bias voltage to achieve equilibrium between layer deposition and etching so that neither a significant material removal nor a significant material buildup occurs, but instead, introducing metal ions into a substrate surface or into a layer of the multilayer system, with the metal ions introduced into the substrate surface or into a layer of the multilayer system including ions of a metal that is a component of a subsequent layer of the multilayer system.
13. The method as recited in claim 12 , wherein a layer of the multilayer system comprises at least one of the group consisting of a carbide layer, an oxide layer, and a nitride layer.
14. The method as recited in claim 12 , wherein a layer of the multilayer system has one or more metallic components.
15. The method as recited in claim 14 , wherein the layer of the multilayer system comprises at least one of the group consisting of Ti, Al, B, Si, TiAl, and AlCr.
16. The method as recited in claim 12 , wherein a layer of the multilayer system is a layer of titanium nitride, titanium carbon nitride, titanium aluminum nitride, aluminum oxide, aluminum chromium oxide, boron nitride, or silicon nitride.
17. The method as recited in claim 12 , wherein the introduced metal ions are a metallic component of the subsequent layer of the multilayer system.
18. The method as recited in claim 12 , comprising letting reactive gas containing oxygen into the vacuum treatment system during the metal ion bombardment.
19. The method as recited in claim 12 , comprising using targets for the metal ion bombardment, wherein the targets are composed of materials that are also used to synthesize an oxide layer.
20. The method as recited in claim 12 , comprising using an alloy target for the metal ion bombardment.
21. The method as recited in claim 12 , comprising selecting the bias voltage to ensure that a layer of the multilayer system has a high density and stress resulting from acceleration of the ions toward the substrate.
22. The method as recited in claim 12 , comprising eliminating a working gas and carrying out the method in only a reactive gas.