Evidence of 2D intersubband scattering in thin film fully depleted silicon-on-insulator transistors operating at 4.2 K

We report the observation at low temperature of a hump in the linear transfer characteristic of a thin film fully depleted silicon-on-insulator transistor when a positive bias is applied on the back gate under the buried oxide. This decrease in the current is correlated with the transition from one-subband to two-subband conduction. Electron mobility measurements and calculations are in good agreement with the occurrence of intersubband scattering in carrier transport in the two-dimensional inversion layer.