Journal of Applied Physics vol:73 issue:6 pages:3068-3073
The experimental hysteresis behavior of Si metal-oxide-semiconductor transistors (MOSTs) operated at liquid-helium temperatures (LHT) is described in detail. It is demonstrated that two different hysteresis regimes can be distinguished: a kink-related counterclockwise and a prekink clockwise regime. The difference in hysteresis sense is related to the different physical mechanisms underlying the phenomena. It is demonstrated that there exists a strong relationship between the hysteresis and the transient behavior of a Si MOST at 4.2 K. The possible transient mechanisms, e.g., self-heating or dopant ionization, are critically reviewed. The transient results presented are in line with the field-assisted ionization of the frozen-out dopant atoms in the Si substrate. For the counterclockwise hysteresis regime an improved analysis is presented, which is based on the original forced depletion layer formation approach. In the companion article the transient behavior in the prekink, clockwise regime is described in detail and discussed in view of the different possible dopant ionization mechanisms at LHT.