A method for fabricating a semiconducting device on a substrate, where the improvement
includes forming a strained silicon germanium channel layer on the substrate. A
gate insulation layer is formed on top of the strained silicon germanium channel
layer, at a temperature that does not exceed about eight hundred centigrade. A
gate electrode is formed on top of the gate insulation layer, and the gate electrode
is patterned. A low dose drain dopant is impregnated into the substrate, and activated
with a first laser anneal. A source-drain dopant is impregnated into the substrate,
and activated with a second laser anneal. After the step of activating the low
dose drain dopant with the first laser anneal, an insulating layer is formed around
the gate electrode, at a temperature that does not exceed about eight hundred centigrade,
and a spacer is formed around the gate electrode. The spacer is formed of a material
that is reflective to the second laser anneal. Thus, standard materials for the
spacer, such as silicon oxide or silicon nitride are not preferred for this application,
because they tend to be transparent to the laser beam emissions.