An inversion layer is formed within the channel region adjacent the gate dielectric, with the inversion layer having a pinch-off region within the phase change material adjacent the drain region.

Hot carriers (for instance, electrons) within the pinch-off region are utilized to change a phase within the phase change material.

By the forming space charge region at raising drain potentials a shielding of the drain potential results because the space charge region touches the field oxide between source and drain at the pinch-off region.

A high voltage NMOS transistor is proposed where the p-doped body is isolated against the p-doped substrate by a DN well showing a pinch-off region where the depth of the DN-well is at minimum.