Study on thermal elastic damping of micro-scale semiconductor beams

Thermoelastic damping (TED) is a fundamental dissipation mechanism that inevitably exists in high-performance micro/nano-electro-mechanical systems. In this paper, the damping characteristics in semiconductor microbeam are studied under coupled carrier-thermo-elastic theory. Using conventional LR model and considering the effect of carrier, the governing equations for TED in semiconductor beam were obtained and the analytical solution for temperature and carrier density was obtained using complex frequency method. The expression for inverse quality factor was given by solving the vibration equation. The effects of cantilever beam size, material parameters, temperature, and doping concentration on TED were studied, and the results showed that the carrier has significant influence on the dissipation performance of semiconductor microstructures. The study also indicated that when carrier characteristics are ignored, this conclusion can degenerate into classical TED results under LR model.