Etching characterization of shaped hole high density plasma for using MEMS devices

High aspect ratio microstructure technology is the key technology for advanced fabrication of microelectro mechanical systems (MEMS). High aspect ratio hole etching for silicon was investigated as a function of platen power, platen temperature, and coil power. Their effects on etch profile angle, scallops, and etch rate were also studied. As the platen power was increased from 5 to 30 W, the etch rate was increased from 0.37 to 3.18 μm/min. However, the etch rate was decreased at a platen power higher than 30 W. As the coil power was increased from 600 to 2400 W, the etch rate was increased from 2.95 to 3.19 μm/min, but the etch rate was decreased at the coil power higher than 1200 W. As the platen temperature was increased from 10 to 30 °C, the scallops decreased from 139 to 122 nm. Etched cross section was observed on 40-μm in diameter hole properties by scanning electron microscopy (SEM).