INNOLEC Lecture: Gregorz Greczynski

Department of Plasma Physics and Technology and CEPLANT Center cordially invites you to a INNOLEC lecture from professor Gregorz Greczynski, a leading expert in HiPIMS and XPS technologies. Prof. Greczynski is the gead of the Fundamental Science of Thin Films unit at the Department of Physics, Chemistry and Biology at Linköping University, Sweden.

Gregorz Greczynski – Benefits of metal-ion irradiation for nanostructure and phase control during thin film growth by magnetron sputtering

Ion irradiation is a key tool for controlling the nanostructure, phase content, and physical properties of refractory ceramic thin films grown by magnetron sputtering. Up until recently, thin film growth by magnetron sputtering relied on enhancing adatom mobility in the surface region by gas ion irradiation to obtain dense layers at low deposition temperatures.

Development of high power pulsed magnetron sputtering (HiPIMS), which provides metal-ion plasmas with tunable degree of ionization, enabled systematic studies of the effects of metal-ion irradiation on properties of refractory ceramic thin films. The original motivation for the use of metal-ions stems from the fact that they are film constituents, hence they can provide the benefits of ion-mixing (film densification at low film-growth temperatures) without causing the high compressive stresses associated with trapping of gas ions in interstitial sites.

Extensive studies conducted in our group during last decade using predominantly transition metal nitride model systems and a hybrid configuration with one target powered by HiPIMS, and the other operated in direct current magnetron sputtering (DCMS) mode, revealed the crucial role of the incident ion mass. Irradiation with lower-mass metal-ions (e.g., Al+ or Si+) results in the near-surface trapping with the depth which can be controlled by the amplitude of synchronously applied bias pulses. This allows unprecedented control over the phase content of metastable ternary nitrides.

At the other extreme, bombardment of the growing film surface with pulsed high-mass metal ion fluxes (e.g., W+ or Ta+) provides fully-dense, low stress, films without intentional substrate heating (substrate temperature during growth is lower than 130 oC). The high metal-ion mass irradiation leads to effective low-energy recoil generation that provide sufficient adatom mobility, necessary to obtain high-quality fully-dense films, in the absence of conventionally used resistive heating. Thus, the process energy consumption is greatly reduced, while the new possibilities open up for coating temperature-sensitive substrates.