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

fYear

2015

fDate

17-22 May 2015

Firstpage

1

Lastpage

4

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 Sc_0.32-Al_0.68 targets, respectively. C-axis orientation was lost in thin films deposited on the Sc_0.43-Al_0.57 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 Sc_0.43-Al_0.57 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;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium (IMS), 2015 IEEE MTT-S International

Conference_Location

Phoenix, AZ

Type

conf

DOI

10.1109/MWSYM.2015.7166841

Filename

7166841