Abstract: A semiconductor structure, particularly a gate stack, useful in field effect transistors (FETs) in which the threshold voltage thereof is controlled by introducing a fixed spatial distribution of electric charge density to the gate dielectric material and a method of forming the same are provided. nFETs and/or pFETs structures are disclosed. In accordance with the present invention, the fixed spatial distribution of electric charge density of the gate stack or FET denotes an electrical charge density that occupies space which remains substantially constant as a function of time under device operation conditions and is non-zero at least at one location within the dielectric material or at its interface with the channel, gate electrode, spacer, or any other structural elements of the device.