A semiconductor device structure includes at least two field effect
transistors formed on same substrate, the first field effect transistor
includes a spacer having a first width, the second field effect
transistor includes a compressive spacer having a second width, the first
width being different than said second width. Preferably, the first width
is narrower than the second width. A tensile stress dielectric film forms
a barrier etch stop layer over the transistors.