A simplified model for subpinchoff conduction in depletion-mode IGFET's

An expression is developed for the
I-V
characteristics of a depletion-mode device in the subpinchoff region. This expression is found to correlate well with experimental results taken on n-channel polysilicon gate devices, predicting a region of exponential current rise with gate voltage. It is of interest to note that the subpinchoff
I-V
characteristics of a depletion-mode device form a dual to those of an enhancement-mode device.