Abstract
Abstract
Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, designed by the combination of a spring network model and finite element method simulations, the stress at critical locations was mitigated and the cracking issue was solved. Meanwhile, the tethered-beam structure was found to be potentially a powerful method for high-precision strain measurement in tensile thin films, and in this case, a strain of
2.27
(
±
0.01
)
×
10
−
3
was measured in 350 nm epitaxial GaN-on-Si.
Funder
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Subject
Materials Chemistry,Electrical and Electronic Engineering,Condensed Matter Physics,Electronic, Optical and Magnetic Materials