DocumentCode :
1247039
Title :
Characterization of 36/spl deg/YX-LiTaO/sub 3/ wafers by line-focus-beam acoustic microscopy
Author :
Kushibiki, J. ; Ishiji, H. ; Kobayashi, T. ; Chubachi, N. ; Sahashi, I. ; Sasamata, T.
Author_Institution :
Dept. of Electr. Eng., Tohoku Univ., Sendai, Japan
Volume :
42
Issue :
1
fYear :
1995
Firstpage :
83
Lastpage :
90
Abstract :
Application of line-focus-beam (LFB) acoustic microscopy is extended to characterization of substrates for SH-type SAW devices. Theoretical and experimental studies on a wave mode for characterization are carried out on 36/spl deg/Y-cut LiTaO/sub 3/ wafers. A Rayleigh-type mode of leaky surface acoustic waves (LSAWs) must be employed instead of an SH-type mode of leaky pseudo-surface waves (LPSAWs). Experimental results show that the LSAW propagation should be directed along the X-axis because the LSAW velocities are more sensitive to chemical composition and elastic inhomogeneities. The relations among the LSAW velocities, densities, and Curie temperatures are determined. The LSAW velocity increases linearly at the rate of 0.52 m/s//spl deg/C with the Curie temperature. A chemical composition change of 0.03 Li/sub 2/O-mol%, corresponding to temperature resolution of better than 0.3/spl deg/C, is easily detected by the velocity measurements. Elastic inhomogeneities due to residual multi-domains, produced during the poling process during wafer fabrication, are interpreted quantitatively by this ultrasonic technology.<>
Keywords :
Curie temperature; Rayleigh waves; acoustic microscopy; lithium compounds; surface acoustic wave devices; ultrasonic velocity; 36/spl deg/YX-LiTaO/sub 3/ wafers; Curie temperatures; LSAW velocities; LiTaO/sub 3/; Rayleigh-type mode; SH-type SAW devices; chemical composition; elastic inhomogeneities; leaky surface acoustic waves; line-focus-beam acoustic microscopy; poling process; residual multi-domains; temperature resolution; ultrasonic technology; velocity measurements; wafer fabrication; wave mode; Acoustic applications; Acoustic devices; Acoustic propagation; Acoustic waves; Chemicals; Fabrication; Microscopy; Surface acoustic wave devices; Temperature sensors; Velocity measurement;
fLanguage :
English
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-3010
Type :
jour
DOI :
10.1109/58.368309
Filename :
368309
Link To Document :
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