Title :
Iridium interdigital transducers for ultra-high-temperature SAW devices
Author :
Aubert, Thierry ; Elmazria, Omar ; Bardong, Jochen ; Bruckner, Gudrun
Author_Institution :
Inst. Jean Lamour, Nancy Univ., Vandoeuvre-lès-Nancy, France
Abstract :
Iridium is investigated as a potential metal for interdigital transducers (IDTs) in surface acoustic wave (SAW) devices operating at high temperatures. SAW delay lines based on such IDTs and langasite (LGS) substrate are fabricated and electrically characterized. The results show reliable frequency responses up to 1000°C. The strong increase of insertion losses beyond this temperature, leading to the vanishing of the signal between 1140 and 1200°C, is attributed to surface transformation of LGS crystal, consisting in relevant gallium and oxygen losses, as evidenced by scanning electron microscopy, energy-dispersive X-ray spectroscopy and secondary ion mass spectroscopy.
Keywords :
X-ray chemical analysis; acoustic signal processing; high-temperature effects; interdigital transducers; iridium; scanning electron microscopy; secondary ion mass spectra; surface acoustic wave transducers; IDT; Ir; SAW delay lines; electrical properties; energy-dispersive X-ray spectroscopy; frequency responses; gallium losses; insertion losses; iridium interdigital transducers; langasite substrate; oxygen losses; scanning electron microscopy; secondary ion mass spectroscopy; signal vanishing; surface acoustic wave devices; surface transformation; ultrahigh-temperature SAW devices; Crystals; Metals; Substrates; Surface acoustic wave devices; Surface acoustic waves; Temperature measurement; Temperature sensors;
Conference_Titel :
Ultrasonics Symposium (IUS), 2011 IEEE International
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4577-1253-1
DOI :
10.1109/ULTSYM.2011.0512
