Title :
High performance bulk acoustic resonator based on ZnO:Li piezofilms with high crystallinity and uniformity
Author :
Chun-Cheng Lin ; Jian-Fu Tang ; Sheng-Yuan Chu
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
This work describes a bulk acoustic resonator (BAR) based on Pt/L0.06Z0.94O/Pt/Ti/Si structure. The L0.06Z0.94O piezofilms are grown by radio frequency magnetron sputtering system and post-treated with ultraviolet (UV)-ozone illumination. The structural and chemical evolutions through various illumination times of the predominantly c-axis orientation LZO films are investigated. The largest piezoelectric coefficient (14.87 pC/N) of the LZO film is obtained after 120 min UV-ozone illumination, which can be ascribed to better crystallization and fewer oxygen-related defects. Furthermore, we adopt the wet chemical etching method and the lift-off process to pattern the piezofilms and electrodes of the BAR device, respectively. The fabricated resonator exhibits high quality factor (Q = 1112) at ~500 MHz. The experimental results verify the crystallinity and the uniformity of the piezofilms play crucial roles of the BAR devices.
Keywords :
II-VI semiconductors; Q-factor; acoustic resonators; bulk acoustic wave devices; crystallisation; etching; lithium; piezoelectric thin films; sputter deposition; ultraviolet radiation effects; wide band gap semiconductors; zinc compounds; BAR device electrodes; Pt-Li0.06Zn0.94O-Pt-Ti-Si; bulk acoustic resonator; c-axis orientation LZO films; crystallization; lift-off process; oxygen-related defects; piezoelectric coefficient; piezofilm uniformity; quality factor; radio frequency magnetron sputtering system; time 120 min; ultraviolet-ozone illumination; wet chemical etching method; Etching; Switches; Tin;
Conference_Titel :
Nanotechnology Materials and Devices Conference (NMDC), 2013 IEEE 8th
Conference_Location :
Tainan
Print_ISBN :
978-1-4799-3386-0
DOI :
10.1109/NMDC.2013.6707456
