Doping Characteristics of Polycrystalline Silicon Deposited by Chemical Transport at Atmospheric Pressure and its Application to MEMS Sensor

This paper reports the doping properties of polycrystalline silicon (poly-Si) deposited by atmospheric pressure plasma enhanced chemical transport and its application to a piezo-resistive pressure sensor. The doping is done by the chemical transport of dopants in Si sources. The structural and electronic properties reveal that most of the dopants are chemically transported at the same rate as the chemical transport of Si and activated as grown. A piezo-resistive pressure sensor is fabricated with the doped poly-Si film. All processes are carried out below 250 °C. The piezo-resistor shows the good linearity of the resistance change rate with the stress. These results indicate that our Si deposition method has adequate potential for nonvacuum and low temperature MEMS processes.