5.5.1 Dependence on Gate Voltage Low-Level

To compare stress and relaxation properly, the initial charge pumping signal  it
Icp,0   should stay constant over the whole considered low level gate voltage VG   -region. Hence, under the assumption that only interface states contribute, Icp   should actually become independent of VG,low   as soon as the strong inversion regime is reached. This Icp,0it   is marked by the dashed line in Fig. 5.13. However, as demonstrated previously [4443], Icp   continues to increase, albeit at a much slower rate. This increase with ΔVG   is routinely attributed to slower oxide traps ΔNot   and Icp = I it + I ot
      cp    cp   [4797]. So, regardless of the amount of degradation, I
 cp   varies as function of V
 G,low   . This fact has to be taken into account for a meaningful comparison of stress and relaxation CP data.