AVS 54th International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP9
Pretreatment by High Power Impulse Magnetron Sputtering - Interface Structure and Stress Evolution

Tuesday, October 16, 2007, 6:00 pm, Room 4C

Session: Advanced Surface Engineering Poster Session
Presenter: D. Jädernäs, Linköping University, Sweden
Authors: D. Jädernäs, Linköping University, Sweden
M. Lattemann, Linköping University, Sweden
U. Helmersson, Linköping University, Sweden
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Substrate pretreatment using metal ion bombardment is an effective way of promoting film-substrate adhesion. In this work we have used high power impulse magnetron sputtering (HIPIMS) to produce the Cr-ions that are bombarding the high speed steel substrates with an applied negative substrate bias, Ub, between 200 and 1100 V. During pretreatment and subsequent film growth, the stress evolution was measured and the adhesion of the films was evaluated using scratch testing. Some samples were also post-annealed at a temperature of 900 K. The results showed that all pretreatment conditions result in a compressive stress that can be correlated to Ub. The stress induced during pretreatment was also shown to affect the growth of the subsequently grown film. For Ub below 600 V significant etching did not occur and a Cr-layer was formed. In this case, the native oxide on the steel remained. For higher Ub values the oxide layer was removed. For the non-annealed films a strong correlation between Ub and adhesion was observed. Substrates with the oxide layer intact showed low film adhesion. After annealing all samples showed an increased adhesion and no clear trend between different pretreatments and adhesion could be observed. The interfacial chemistry and structure were examined in order to find the correlation between structure, chemistry and adhesion. The results show that strong interfaces, capable of resisting an applied force, can be produced even though an oxide is still present.