The state of coating–substrate interfacial region formed during TiO2 coating deposition by Gas Injection Magnetron Sputtering technique

• Published in: Surface & coatings technology Vol. 398; p. 126092
• Main Authors: Chodun, Rafal, Nowakowska-Langier, Katarzyna, Wicher, Bartosz, Okrasa, Sebastian, Kwiatkowski, Roch, Zaloga, Dobromil, Dypa, Marlena, Zdunek, Krzysztof
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.09.2020; Elsevier BV
• Subjects: Amplitudes; Anatase; Coating-substrate interface; Crystallization; Deposition; Emission analysis; Gas injection; HRTEM; Kinetic energy; Magnetron sputtering; Nucleation; OES; Optical emission spectroscopy; Plasma; Plasmas (physics); Pressure oscillations; Raman spectroscopy; Spectrum analysis; Substrates; Titanium dioxide; Magnetron sputtering; OES; Raman spectroscopy; Titanium dioxide; Coating-substrate interface; HRTEM
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2020.126092

This manuscript presents the nature of interaction of energetic plasmoids, generated in the Gas Injection Magnetron Sputtering (GIMS) technique, with the surface of substrate or the coating–substrate system. We expected that the plasma generated by a dynamic injection of gas (GIMS) is better ionized than the plasma generated in stationary pressure in its standard range for magnetron sputtering. The GIMS technique operates under conditions that may favor the plasma species to retain their kinetic energy, limiting the probability of intermolecular collisions events. In this experiment, the frequency of injecting small amounts of gas was used as a parameter to control the pressure amplitudes, thus achieving the conditions of plasma generation from stationary, through quasi-stationary, to pulsed oscillations of pressure. The optical emission spectroscopy (OES) was used to evaluate the state of deposition environment in GIMS. Investigation showed that the plasma spectrum consists of higher population of ions in the conditions of high amplitude of pressure oscillations. The phase content of a titanium dioxide coating, deposited under various conditions of plasma generation, also depends on the energetic state of plasma. Raman spectroscopy proved that the stationary condition favors the anatase phase as the nucleation phase, while with the increase in the non-equilibrium of plasma, the metastable rutile phase is more expected. The effects of strong impingement of energetic species were observed, causing crystallization of the amorphous phase of coatings, with sputtering of the substrate surface and the formation of a specific type of coating–substrate interfacial region. •GIMS generates plasma by injection of gas in the discharge region of magnetron.•Plasma generated by GIMS is more energetic than stationary magnetron plasma.•GIMS favors deposition of TiO2 coating material in its metastable form of rutile.•Energy of GIMS plasma species is high enough to sputter the substrate material.•Creation of a uniform coating–substrate interfacial region is possible by GIMS.