Method for pretreating substrates for pvd methods

Abstract

The invention relates to a method for surface treatment of work pieces in a vacuum treatment system having a first electrode embodied as a target, which is part of an arc vaporization source; by means of the first electrode, an arc is operated with an arc current and vaporizes material from the target that is deposited at least partially and intermittently onto the work pieces and having a second electrode that is embodied as a work piece holder and, together with the work pieces, constitutes a bias electrode; by means of a voltage supply, a bias voltage is applied to the bias electrode, with the bias voltage applied so that it is matched to the arc current such that essentially, no net material buildup on the surface occurs.

1 . A method for surface treatment of 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 with an arc current and vaporizing material from the target that is deposited at least partially and intermittently onto the work pieces, wherein a second electrode that is embodied as a work piece holder, together with the work pieces, constitutes a bias electrode;   using a voltage supply, applying a bias voltage to the bias electrode, with the bias voltage applied so that the bias voltage is matched to the arc current such that essentially, no net material buildup on the surface occurs,   wherein the first electrode is operated with a pulsed current; and   the pulsation results in an increased substrate current through the work piece surface as compared to non-pulsed operation and as a result, with a lower bias voltage in comparison to non-pulsed operation of the first electrode, no net material buildup on the surface occurs.   
     
     
         2 . The method as recited in  claim 1 , comprising carrying out the method without working gas and/or without reactive gas. 
     
     
         3 . The method as recited in  claim 1 , comprising operating the substrate bias voltage in a pulsed fashion. 
     
     
         4 . The method as recited in  claim 3 , wherein a currently present pulse frequency of the substrate bias voltage is an integral multiple of the pulse frequency of the arc current, including a multiplication by one. 
     
     
         5 . The method as recited in  claim 4 , wherein relative to the pulsing of the arc current, the pulsing of the bias voltage is phase shifted by a time interval that essentially corresponds to the average flight time of the ions from the target to the substrate. 
     
     
         6 . The method as recited in  claim 1 , comprising using a hard metal as a substrate; wherein the substrate surface is a cutting edge such as a thread-cutting insert; and carrying out the method to heal a cobalt depletion of the surface. 
     
     
         7 . The method as recited in  claim 1 , wherein the target material and/or a reaction gas chemically react(s) with material components of the substrate, thereby producing more stable components. 
     
     
         8 . The method as recited in  claim 7 , comprising using a metallic target as the target, wherein the substrate contains carbon, and the chemical reaction results in the formation of carbides. 
     
     
         9 . The method as recited in  claim 1 , comprising selecting the pulse of the arc current so that current rise values of at least 1,000 A/ms occur. 
     
     
         10 . The method as recited in  claim 1 , wherein an average substrate ion current increase—relative to the material vaporized from the target (mass per unit arc current per unit time)—yields more than 10% for arc currents (DC and pulsed) that are the same averaged over time. 
     
     
         11 . The method as recited in  claim 1 , wherein zero growth or rates of less than 5 nm/s are achieved on the substrate. 
     
     
         12 . The method as recited in  claim 1 , wherein it is possible to carry out the surface treatment both with and without a baffle plate in front of the arc target. 
     
     
         13 . The method as recited in  claim 1 , comprising using pulse slopes, which are greater than 500 A/ms. 
     
     
         14 . The method as recited in  claim 1 , comprising using pulse frequencies, which are greater than 100 Hz. 
     
     
         15 . The method as recited in  claim 1 , wherein the result is detectable in the formation of chemical bonds in the substrate surface between target material and reactive gas on the one hand and substrate material on the other hand. 
     
     
         16 . The method as recited in  claim 1 , comprising carrying out the method in a reactive gas without the occurrence of a layer buildup. 
     
     
         17 . A use of the method as recited in  claim 1  for at least partial healing of depleted material concentration on the surface as compared to the substrate interior.