Title :
Highly c-axis-oriented ScAlN thin films deposited using Sc-Al alloy target
Author :
Fujii, Satoshi ; Sumisaka, Masahiro ; Tang, Gonbin ; Suzuki, Yu ; Otomo, Shohei ; Omori, Tatsuya ; Hashimoto, Ken-ya
Author_Institution :
Grad. Sch. of Sci. & Eng., Tokyo Inst. of Technol., Tokyo, Japan
Abstract :
ScAlN thin films were deposited by a conventional radiofrequency (RF)-magnetron sputtering system using two Sc-Al alloy metal targets with different Sc/Al ratios. A 10 h deposition time resulted in highly c-axis-oriented ScAlN thin films with Sc concentrations of 32 at% and 22 at% on Sc0.43-Al0.57 and Sc0.32-Al0.68 targets, respectively. C-axis orientation was lost in thin films deposited on the Sc0.43-Al0.57 target after sputtering times of over 50 h. XDS analysis showed a high-Sc-content ScAlN film with an amorphous phase layer near the Si substrate surface. A seed layer of c-axis-oriented ScAIN allowed for > 50 h deposition on the Sc0.43-Al0.57 target to result in highly c-axis-oriented ScAlN films. A one-port surface acoustic wave (SAW) resonator based on the ScAlN/Si structure has a K2 value of 2.7% at 2 GHz, six times larger than for that based on the AlN/Si structure.
Keywords :
aluminium compounds; amorphous state; piezoelectric thin films; piezoelectricity; scandium compounds; sputter deposition; surface acoustic wave resonators; K2 value; SAW resonator; Sc concentrations; Sc-AI alloy target; ScAl; ScAlN; Si substrate surface; XDS; amorphous phase layer; conventional radiofrequency-magnetron sputtering system; frequency 2 GHz; highly c-axis-oriented ScAIN thin films; one-port surface acoustic wave resonator; Artificial intelligence; Magnetic analysis; Magnetic films; Magnetic resonance imaging; Radio frequency; Silicon; RF magnetron sputtering; SAW resonator; ScAlN thin film;
Conference_Titel :
Microwave Symposium (IMS), 2015 IEEE MTT-S International
Conference_Location :
Phoenix, AZ
DOI :
10.1109/MWSYM.2015.7166841
