Methods for fabricating a stressed MOS device [30] is provided. One method comprises the steps of providing a monocrystalline semiconductor substrate [36] having a surface [32] and a channel [70] abutting the surface. A gate electrode [66] having a first edge [75] and a second edge [85] is formed overlying the monocrystalline semiconductor substrate. The substrate is anisotropically etched to form a first recess [82] aligned with the first edge [75] and a second recess [84] aligned with the second edge [85]. The substrate is further isotropically etched to form a third recess [96] in the substrate extending beneath the channel [70]. The third recess is filled with an expanding material [100] to exert an upward force [101] on the channel and the first [82] and second [84] recesses are filled with a contact material [HO]. Conductivity determining ions are implanted into the contact material [110] to form a source region [130] and a drain region [132] aligned with the first [75] and second edges [85], respectively.