Title :
Noncontact characterization of crystal surface and thin films by the phase velocity scanning of laser interference fringes
Author :
Yamanaka, K. ; Nishino, H. ; Cho, H. ; Nagata, Y. ; Koda, T. ; Inaba, M. ; Sato, A. ; Tsukahara, Y.
fDate :
Oct. 31 1994-Nov. 3 1994
Abstract :
We present the first application of a novel noncontact velocity measurement method of surface acoustic waves (SAW) to evaluation of thin films. This method uses laser interference fringes scanned at the phase velocity of SAW. The scanning interference fringes (SIF) are produced by intersecting two laser beams with a frequency difference. It was found that the Si3N4 film prepared by low pressure CVD had similar elastic properties to that of a sintered body. The dispersive Sezawa waves on the flame hydrolysis deposited SiO2 films on Si (100) surface were detected. Comparing the measured Sezawa wave velocity with calculated velocity, the films were found to be much softer than bulk SiO2 (fused quartz)
Keywords :
CVD coatings; elasticity; insulating thin films; light interference; silicon compounds; surface acoustic waves; ultrasonic dispersion; ultrasonic velocity; ultrasonic velocity measurement; Si; Si [100] surface; Si3N4 CVD film; Si3N4-Si; SiO2 films; SiO2-Si; crystal surface; dispersive Sezawa waves; elastic properties; flame hydrolysis deposition; frequency difference; laser interference fringes; low pressure CVD; noncontact surface characterization; noncontact velocity measurement method; phase velocity scanning; scanning interference fringes; surface acoustic waves; thin films; Acoustic velocity measurement; Acoustooptic measurements; CVD; Dielectric films; Mechanical factors; Silicon materials/devices; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE
Conference_Location :
Cannes, France
Print_ISBN :
0-7803-2012-3
DOI :
10.1109/ULTSYM.1994.401803
