Dispozitive SAW realizate pe semiconductori de tip III – Nitruri pentru aplicatii in senzori si in cuplarea undelor acustice cu undele de spin / SAW devices based on III – Nitrides for applications in sensors and coupling acoustic waves with spin waves

Frequency limitations of resonance frequencies for SAW devices, fabricated on classical piezoelectric bulk substrates like Lithium Niobate, Lithium Tantalite, Quartz, etc. generate novel technologies for manufacturing of SAW devices. One of them consists in SAW manufacturing on thin layers of wide bandgap III-Nitride type piezoelectric semiconductor layers like GaN, AlN, ScAlN, deposited or grown on bulk semiconductor (Si, SiC, Diamond) or dielectric (Sapphire) substrates. The topic of this thesis targets developing of SAW devices on such novel layered structures and also on the development of novel and performant temperature and magnetic sensors. The work also has analyzed the coupling of surface acoustic waves with spin waves, using, for the first time, a SAW structure manufactured on ScAlN/Si. In most applications, the increase of the resonance frequencies (which can exceed 10 GHz for such layered structures) has beneficial effects. The work has 7 chapters; after an introduction (chapter 1), in chapters 2-5 there are presented the novel devices developed and the most important original results. The presentation fits on authors main scientific contributions (journal and conference papers). The author describes a few novel temperature sensors, a magnetic sensor, all developed on different layered structures; he also presents a very efficient coupling of surface acoustic waves with spin waves, for the first time on a ScAlN/Si structure, for both the Rayleigh mode as well as for the Sezawa mode, fist time. The work had as result 6 ISI publications (1 Q1, 4 Q2, 1 Q4) and 6 papers published in the Proceedings of important conferences. The publication list, and the effective contribution of the author to each paper are detailed in chapter 6. The conclusions are presented in the last chapter, 7.