Low Stress Oxide‐Polysilicon Sandwiched Microbridges

Residual stresses in thin films have an important bearing on the formation of free‐standing microstructures using conventional silicon technology. Thermal processing constraints become even more restrictive when multilayer composite microstructures are required. We report here on the fabrication of silicon dioxide‐polysilicon‐silicon dioxide microbridges with low residual stresses on crystalline silicon substrates using appropriate annealing procedures and an anisotropic etch.