A strained-channel transistor structure with lattice-mismatched zone and fabrication
method thereof. The transistor structure includes a substrate having a strained
channel region, comprising a first semiconductor material with a first natural
lattice constant, in a surface, a gate dielectric layer overlying the strained
channel region, a gate electrode overlying the gate dielectric layer, and a source
region and drain region oppositely adjacent to the strained channel region, with
one or both of the source region and drain region comprising a lattice-mismatched
zone comprising a second semiconductor material with a second natural lattice constant
different from the first natural lattice constant.