Energy position of the active near-interface traps in metal–oxide–semiconductor field-effect transistors on 4H–SiC

摘要

Based on the insight that the Fermi level in a metal-oxide-semiconductor field-effect transistor (MOSFET) channel is set in the conduction band, due to the quantum confinement of the channel electrons, this letter provides an experimental demonstration that the near-interface traps responsible for degradation of channel-carrier mobility in SiC MOSFETs are energetically aligned to the conduction band of SiC. The experimental demonstration is based on conductance measurements of MOS capacitors in accumulation. The accumulation conductance does not change with temperature, which demonstrates that there is channel-carrier communication with the near-interface traps by tunneling.