Nanocrystalline diamond piezoresistive sensor

The design, fabrication and test of piezoresistive sensors based on nanocrystalline diamond (NCD) films are reported. The CoventorWare FEM calculations of the mechanical stress and geometrical deformations of a 3-D structure are used for a proper localization of the piezoresistor on the carrying substrate. The boron-doped piezoresistive sensing element was realized using a directed patterned growth of NCD film on SiO2/Si by microwave plasma-enhanced chemical vapour deposition (CVD). The gauge factor of boron-doped NCD films was investigated in the range from room temperature up to 200 °C and from 0 to 5 N of the applied force. These NCD piezoresistive sensor elements are compared with a Silicon-on-Insulator (SOI) based piezoresistive sensor and their high-temperature applications are discussed.