GATE-ALL-AROUND (GAA) FIELD-EFFECT TRANSISTOR (FET) DEVICE EMPLOYING STRAIN MATERIAL IN INACTIVE GATE REGION(S) FOR APPLYING CHANNEL STRAIN FOR INCREASED CARRIER MOBILITY, AND RELATED FABRICATION METHODS

Gate-all-around (GAA) field-effect transistor (FET) device employing strain material structure in inactive gate region(s) of a gate for applying channel strain to the channel(s) of the GAA FET for increased carrier mobility. The GAA FET device includes a GAA P-type (P) FET (PFET) and a GAA N-type (N) FET (NFET) served by a gate with a strain material in the inactive gate region(s) of the gate adjacent to the active gates of the GAA NFET and GAA PFET. In this manner, the strain material applies strain to both the GAA NFET and GAA PFET channels in the elongated direction of the gate in a direction orthogonal to their channel directions between the respective sources and drains, so that a strain material of the same strain type can be used to increase carrier mobility of both the GAA NFET and GAA PFET alike.