Copper phthalocyanine suspended gate field effect transistors for NO2 detection

NO2 sensitive suspended gate (SG) field effect transistors (FET) based on copper phthalocyanine (CuPc) thin layers have been produced and investigated. The sensor structure is a hybrid one. The SG includes the CuPc sensing layer deposited in an independent process by thermal evaporation on the gate electrode (Au/alumina wafer). The transducer (FET) platform realised in standard complementary-metal-oxide-semiconductor (C-MOS) technology and containing several measuring and reference channels is mounted using the flip-chip technology over the gate structure. The sensing layers and the sensors are showing low detection limit (<50 ppb) and good sensitivity (20–70 mV/concentration decade), selectivity and reproducibility.