METHOD OF FORMING MULTIPLE-VT FETS FOR CMOS CIRCUIT APPLICATIONS

A field-effect transistor (FET) device having a modulated threshold voltage (Vt) includes a source electrode, a drain electrode, a channel region extending between the source electrode and the drain electrode, and a gate stack on the channel region. The gate stack includes an ultrathin dielectric dipole layer configured to shift the modulated Vt in a first direction, a high-k (HK) insulating layer on the ultrathin dielectric dipole layer, and a gate metal layer on the HK insulating layer configured to shift the modulated Vt in a second direction.