Title :
Fabrication of 5-GHz-band SAW filter with atomically-flat-surface AlN on sapphire
Author :
Uehara, K. ; Yang, C.-M. ; Shibata, T. ; Kim, S.-K. ; Kameda, S. ; Nakase, H. ; Tsubouchi, K.
Author_Institution :
Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan
Abstract :
5-GHz-band surface acoustic wave (SAW) filters for mobile communications were fabricated on an atomically-flat-surface (0001)aluminum nitride/(0001)sapphire (AlN/Al2O3) combination. The SAW devices were fabricated using electron beam lithography and a lift-off method. Atomically-flat-surface AIN films were used to reduce SAW propagation loss. The center frequency of the fabricated SAW filter was 5.18 GHz. SAW velocity was 5688 m/s at normalized thickness by wave number (kH) of 9.9. The effective coupling coefficient was 0.1% and temperature-coefficient of delay was 9 ppm/°C at kH of 5.9. The SAW propagation loss was 0.0053 dB at 5.18 GHz. The atomically-flat-surface (0001)AlN/(0001)Al2O3 combination is promising for use in 5-GHz-band SAW filters for application to mobile communications.
Keywords :
aluminium compounds; electron beam lithography; microwave filters; sapphire; surface acoustic wave filters; ultrasonic propagation; 0.0053 dB; 5 GHz; 5.18 GHz; 5688 m/s; AlN-Al2O3; SAW filter; SAW propagation loss; SAW velocity; atomically-flat filter surface; effective coupling coefficient; electron beam lithography; lift-off method; mobile communications; Acoustic waves; Electron beams; Fabrication; Frequency; Lithography; Mobile communication; Propagation losses; SAW filters; Surface acoustic wave devices; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
Print_ISBN :
0-7803-8412-1
DOI :
10.1109/ULTSYM.2004.1417702
