Title :
The elastic properties of thin-film silicon nitride
Author :
Hickernell, T.S. ; Fliegel, F.M. ; Hickernell, F.S.
Author_Institution :
Motorola Inc., Scottsdale, AZ, USA
Abstract :
The elastic properties of thin-film silicon nitride (Si3N4) were investigated using surface-acoustic-wave (SAW) propagation data for plasma-enhanced chemical-vapor-deposition (PECVD) grown Si3N4 on gallium arsenide. For three films with thicknesses of 102 nm, 250 nm, and 497 nm, elastic constants were calculated from least-squares fits of theoretical dispersion curves to phase velocity data at different film thickness-to-wavelength ratios. The measured film density decreased from 2800 to 2500 kg/m3 with increasing film thickness. Within this density range the longitudinal elastic modulus averaged near 1.83×1011 N/m2 and the shear elastic modulus decreased from 0.918×1011 N/m2 to 0.561×1011 N/m2 as the film density decreased. The elastic moduli of thin-film silicon nitride are comparable to those of Si3N4 ceramics at similar densities
Keywords :
elastic constants; elastic moduli; plasma CVD coatings; silicon compounds; surface acoustic waves; ultrasonic dispersion; ultrasonic velocity; GaAs substrate; PECVD; SAW propagation; Si3N4 thin films; dispersion curves; elastic constants; elastic properties; film density; least-squares fits; longitudinal elastic modulus; phase velocity data; plasma-enhanced chemical-vapor-deposition; shear elastic modulus; velocity dispersion; Ceramics; Chemicals; Density measurement; Gallium arsenide; Plasma chemistry; Plasma properties; Semiconductor thin films; Silicon; Surface acoustic waves; Thickness measurement;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171405
