Patent ID: 6974981

Claim:
An isolation structure for devices formed in a substrate, the devices each having a longitudinal direction and a transverse direction, the structure comprising: a first isolation region for a first one of the devices, the first isolation region having therein a first isolation material which applies a first type of mechanical stress on the first one of the devices in the longitudinal direction and also in the transverse direction; a second isolation region for a second one of the devices, the second isolation region having therein the first isolation material which applies the first type of mechanical stress on the second one of the devices in the transverse direction; and a third isolation region for the second one of the devices, the third isolation region having therein a second isolation material which applies a second type of mechanical stress on the second one of the devices in the longitudinal direction, wherein the first one of the devices is an NFET and the second one of the devices is a PFET, and the first isolation material is TEOS and the second isolation material is HDP.