Mobility degradation of inversion layer carriers due to MERIE-type plasma action

The influence of a MERIE-type plasma on the oxide and the interface properties of thin (11 nn) Si-SiO2 structures has been investigated by means of the inversion channel I-V characteristics of a gateless FET. It has been established that the plasma action leads to a degradation of the inversion carrier mobility and to a change of the dominant scattering mechanism in the inversion channel. The reason for this is found to be the generation of a large amount of charges in the form of a positive oxide charge and negatively charged acceptor-like interface states. The exact energy position of these states depends on the plasma conditions. We propose that plasma induced interface states are mainly attributed to VUV and ion bombardment, whereas the high values of the positive oxide charge are due to the charging effect. The oxide charge is associated with E' centers and the interface states with P-b centers, respectively. Copyright (C) 1996 Elsevier Science Ltd.