Accumulation-punchthrough mode of operation of buried-channel MOSFET's

The current-voltage characteristics of a buried-channel MOSFET operated in a "punchthrough-accumulation" mode, when the neutral implanted channel is completely depleted due to punchthrough by substrate bias and an accumulation layer is induced by the gate, are demonstrated. It is shown that the value of one of the device model parameters, φ
MS
, used under the above mode of operation corresponds to the gate and the substrate rather than to the gate and the channel.