Patent KR-20110088578-A (KR)
Title: Method for pretreating substrates for pvd methods
Inventor: RUDIGIER HELMUT
IPC: C23C14/32
Filed: 2009-10-27
Abstract: The method for the surface treatment of work pieces in a vacuum treatment system having a first electrode that is designed as metallic target partially and temporally deposited on the work pieces and is part of an arc evaporation source and a second electrode that is designed as work piece holder and forms a bias electrode together with the work pieces, comprises operating a spark over the first electrode with spark flow (CC), by which material from the target is evaporated, and applying a bias voltage to the bias electrode by a voltage source in accordance to the spark flow. The method for the surface treatment of work pieces in a vacuum treatment system having a first electrode that is designed as metallic target partially and temporally deposited on the work pieces and is part of an arc evaporation source and a second electrode that is designed as work piece holder and forms a bias electrode together with the work pieces, comprises operating a spark over the first electrode with spark flow (CC), by which material from the target is evaporated, and applying a bias voltage to the bias electrode by a voltage source in accordance to the spark flow such that no material build-up takes place in net terms on the surface. The first electrode is operated with pulsed current, where a substrate current increased against the unpulsed operation is generated by the pulses through the workpiece surface and no material build-up takes place in net terms on the surface during opposite unpulsed operation of the first electrode with low bias voltage. The substrate bias voltage is operated in a pulsed manner. The actual pulse frequency of the substrate bias voltage is an integral multiple of the pulse frequency of the spark flow. The pulses of the bias voltage are phase shifted against the spark flow at a time interval, which corresponds to the average flight time of the ions from the target to the substrate. A hard metal is used as a substrate, where the substrate surface is a cutting edge and an indexable cutting insert. The target material and/or optionally reaction gas chemically react with material components of the substrate and form stable components. The metallic target contains carbon substrate and conducts the chemical reaction for the formation of carbides. The pulses of the spark flow are selected, so that the current rise valves are 10000 A/ms. The averaged substrate ion current rise related to the material evaporated at the target results more than 30% for spark flow equally averaged in time. The zero growth and/or rates of smaller than 5 nm/s are achieved at the substrate. The surface treatment is carried out above the spark target with and without blends. The pulse steepness is larger than 1000 A/ms and the pulse frequency is larger than 1000 Hz. The resultant of the formation of the chemical connections is detectable in the substrate surface between the target material and reactive gas on one side and substrate material on other side. The process is carried out in the reactive gas without layer formation.