2PPNa - Physique et Propriétés des Nanostructures PPNa (Institut PPRIME : Recherche et Ingénierie en Matériaux, Mécanique et Energétique SP2MI Téléport 2 Boulevard Pierre et Marie Curie BP 30179 86962 FUTUROSCOPE CEDEX - France)
PPRIME - Institut Pprime (Institut PPRIME : Recherche et Ingénierie en Matériaux, Mécanique et Energétique
SP2MI Téléport 2
Boulevard Pierre et Marie Curie
BP 30179
86962 FUTUROSCOPE CEDEX - France)
Université de Poitiers : UPR3346 (15, rue de l'Hôtel Dieu - 86034 Poitiers Cedex - France)
Abstract : Ion bombardment during film growth usually induces high compressive stress in compound thin film materials, resulting in rupture and failure of coated tools used in tribological applications. Hence‚ intrinsic stress generated during film growth can drastically limit the industrial appeal of deposition technologies such as high power impulse magnetron sputtering (HiPIMS). This work investigates how to reduce high stress levels by tuning the HiPIMS discharge conditions and selecting the appropriate substrate bias configuration. The strategy is based on optimizing the process discharge parameters, leading to HiPIMS discharges containing fewer multiply charged energetic metal ions, which is combined with pulsed substrate bias synchronized to the HiPIMS pulse to control the chemical nature of the incident ions‚ i.e.‚ inert gas vs. metal ions. The study was performed during growth of TiN thin films, due to their relevance as a protective coating, and the intrinsic stress was measured in situ during film growth using the wafer curvature method and a multi-beam optical stress sensor. The results show that for standard HiPIMS discharges and biased substrates‚ the energetic metal ion bombardment results in very dense, compact microstructures, but highly stressed TiN films. On the other hand‚ when using the here proposed strategy mentioned above‚ the compressive stress was considerably reduced (by a factor 11) while retaining rather compact microstructures compared to direct current magnetron sputtered as well as non-biased HiPIMS samples.
Felipe Cemin, Grégory Abadias, Tiberiu Minea, Daniel Lundin. Tuning high power impulse magnetron sputtering discharge and substrate bias conditions to reduce the intrinsic stress of TiN thin films. Thin Solid Films, Elsevier, 2019, ⟨10.1016/j.tsf.2019.05.054⟩. ⟨hal-02271110⟩