Stress and silicon nitride: a crack in the universal dissipation of glasses.
High-stress silicon nitride microresonators exhibit a remarkable room temperature Q factor that even exceeds that of single crystal silicon. A study of the temperature dependent variation of the Q of a 255 micromx255 micromx30 nm thick high-stress Si3N4 membrane reveals that the dissipation Q-1 decreases with lower temperatures and is approximately 3 orders of magnitude smaller than the universal behavior. Stress-relieved cantilevers fabricated from the same material show a Q that is more consistent with typical disordered materials. e-beam and x-ray studies of the nitride film's structure reveal characteristics consistent with a disordered state. Thus, it is shown that stress alters the Q-1, violating the universality of dissipation in disordered materials in a self-supporting structure.
Southworth
D R
DR
Center for Materials Research, Cornell University, Ithaca, New York 14853, USA.
Barton
R A
RA
Verbridge
S S
SS
Ilic
B
B
Fefferman
A D
AD
Craighead
H G
HG
Parpia
J M
JM