Effect of positive pulse voltage in bipolar reactive HiPIMS on crystal structure, microstructure and mechanical properties of CrN films

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23520%2F21%3A43963209" target="_blank" >RIV/49777513:23520/21:43963209 - isvavai.cz</a>

Alternative codes found

RIV/49777513:23520/20:43960222

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Effect of positive pulse voltage in bipolar reactive HiPIMS on crystal structure, microstructure and mechanical properties of CrN films

Original language description

High-power impulse magnetron sputtering (HiPIMS) is a deposition method where the high power density in a pulse results in high fraction of ionized species of both the working gas and the target material and broadened ion energy distribution function. This leads to an enhanced ion bombardment of the growing film even without the application of a substrate bias voltage. However, a bias voltage might still be necessary to control the energy of the high amount of low-energy thermalized ions. Lately, bipolar HiPIMS, where the main negative voltage pulse is followed by a positive one, has been suggested to be used instead of a substrate bias voltage, particularly when a DC substrate bias voltage is ineffective. In this work, we first use a substrate holder at a floating potential to demonstrate that bipolar HiPIMS cannot be used instead of a DC substrate bias voltage for deposition of non-conductive films or deposition onto non-conductive substrates, due to charging and the loss of a plasma-substrate potential difference, necessary for ion acceleration. However, when the substrate holder is grounded, there is an apparent evolution in crystal structure, microstructure and mechanical properties of the CrN films with increasing positive pulse voltage. We compare the effect of the positive pulse voltage in bipolar HiPIMS with the effect of a standard DC bias voltage applied to the substrate holder in unipolar HiPIMS. We find that the effects are different, mainly due to differences in energies delivered into the growing film by bombarding ions. The most interesting properties, namely high hardness (23.5 and 23.1 GPa) at a relatively low residual stress are achieved for films prepared using bipolar HiPIMS with a grounded substrate holder at positive pulse voltages of 90 and 120 V, respectively.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20506 - Coating and films

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů