Temperature and frequency characterization of InAs nanowire and HfO2 interface using capacitance–voltage method

InAs/HfO2 nanowire capacitors using capacitance–voltage (CV) measurements are investigated in the range of 10 kHz to 10 MHz. The capacitors are based on vertical nanowire arrays that are coated with an 8 nm-thick HfO2 layer by atomic layer deposition. CV characteristics are measured at temperatures in the range between −140 and 40 °C and the CV characteristics for nanowires with different Sn and Se n-type doping levels are compared. The comparison of the data at various doping levels points towards large number of traps for highly doped samples, caused by the preferential dopant precursor incorporation at the nanowire surface. We also evaluate the frequency dispersion of the accumulation capacitance and determine values below 2% with weak temperature dependence, indicating the existence of border traps in these nanowire capacitors.