Abstract

CrN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (0 ≤ x ≤ 0.91) films synthesized using high-power pulsed magnetron sputtering, also known as high-power impulse magnetron sputtering (HiPIMS), have been compared with those made by conventional direct-current (dc) magnetron sputtering (DCMS) operated at the same average power. The HiPIMS deposition rate relative to the DCMS rate was found to decrease linearly with increasing emission strength from the Cr ions relative to Cr neutrals, in agreement with the predictions of the target-pathway model. The low deposition rate in HiPIMS is thus a direct consequence of the high ionization level (~56%) of the target material and effective capturing of Cr ions by the cathode potential. Although the HiPIMS deposition rate did not exceed 40% of the DCMS rate, the drop in the relative deposition rate upon increasing the N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -to-Ar flow ratio, f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N2/Ar</sub> , was found to be similar for both sputtering techniques. Films prepared by HiPIMS contained similar amounts of atomic nitrogen as the dc-sputtered samples grown at the same f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N2/Ar</sub> indicating that the nitride formation at the substrate takes place mostly during the time period of the high-power pulses, and the N2 uptake between the pulses is negligible. The microstructure evolution in the two types of CrN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> films, however, differed clearly from each other. A combination of a high substrate bias and a high flux of doubly charged Cr ions present during the HiPIMS discharge led to a disruption of the grain growth and renucleation, which resulted in column-free films with nanosized grains not observed in the conventional DCMS-based process. The comparison of nanoindentation hardness as a function of f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N2/Ar</sub> revealed superior properties of HiPIMS-sputtered films in the entire range of gas compositions.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.