The present invention provides a strained Si directly on insulator (SSDOI)
substrate having multiple crystallographic orientations and a method of
forming thereof. Broadly, but in specific terms, the inventive SSDOI
substrate includes a substrate; an insulating layer atop the substrate;
and a semiconducting layer positioned atop and in direct contact with the
insulating layer, the semiconducting layer comprising a first strained Si
region and a second strained Si region; wherein the first strained Si
region has a crystallographic orientation different from the second
strained Si region and the first strained Si region has a
crystallographic orientation the same or different from the second
strained Si region. The strained level of the first strained Si region is
different from that of the second strained Si region.