A Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is a voltage-controlled majority carrier device that controls conduction via an insulated gate electrode. When the applied gate-to-source voltage V_GS surpasses the threshold voltage V_th, an electrostatic field attracts minority electrons toward the semiconductor-dielectric interface, creating an n-type inversion channel between the n+ source and drain diffusions. In the saturation region, the channel pinches off at the drain end, sustaining a saturation current governed by square-law field-effect dynamics.