Charge state of SOI nanowire sensors

The initial charge state of SOI nanowire sensors after their long storage in air ambient has been identified by measuring the drain-gate characteristics of SOI nanowire transistors. In the examined structures, the density of the surface charge was found to be ranging within the interval 2×10¹²-4×10¹² cm^-2. Two surface treatments were given to the samples to clean the surface of SOI nanowire sensors from contaminations; among these treatments an optimal one was chosen enabling stabilization of the charge state of the sensor surface. The value of the surface charge in sensors immersed in buffer solutions with different pH values was measured.