Study on diamond SAW with high piezoelectric ScAlN thin film

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420299
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: Okinawa National College of Technology (2015-2016); Chiba University (2014)
• Principal Investigator: Fujii Satoshi 沖縄工業高等専門学校, 情報通信システム工学科, 教授 (30598933)
• Co-Investigator(Renkei-kenkyūsha): HASHIMOTO KENYA 千葉大学, 工学研究科, 教授 (90134353) ; OMORI TATSUYA 千葉大学, 工学研究科, 助教 (60302527)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 弾性表面波 / 圧電薄膜 / ダイヤモンド / マイクロ波工学

Outline of Final Research Achievements

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.

Free Research Field

電子部品