Gate straining techniques as described herein can be utilized during the
fabrication of NMOS transistor devices, PMOS transistor devices, or CMOS
device structures. For an NMOS device, conductive vias are formed in TEOS
oxide regions surrounding the sidewall spacers of a metal gate structure,
where the metal gate structure includes compressive nitride material
within the gate opening. After forming the conductive vias the remaining
TEOS oxide is removed and tensile nitride material is deposited between
the sidewall spacers and the conductive vias. The sidewall spacers serve
as retaining walls for the tensile nitride material, which preserves the
tensile characteristics of the material. A similar fabrication technique
is utilized to form a PMOS device. For a PMOS device, however, the metal
gate structure includes tensile nitride material within the gate opening,
and compressive nitride material between the sidewall spacers and the
conductive vias.