Evidence of Sub-Band Modulated Transport in Planar Fully Depleted Silicon-on-Insulator MOSFETs

Modulation of the sub-band electron population in the inversion channel of 10-nm planar fully depleted silicon-on-insulator MOSFETs is evidenced by the bias dependence of inversion layer transport parameters. Two distinct inversion-layer electron species were detected by magnetic-field-dependent magnetoresistance measurements and high-resolution mobility spectrum analysis. According to self-consistent Poisson-Schrödinger calculations, these species correspond to carriers in distinct sub-bands within the Si channel region. The mobility peak of the carrier with the highest sheet density occurs under gate bias conditions that result in a minimum perpendicular effective electric field.