Hi  Matthew,

Yes, It is so, the strained Silicon has less Si-Si bond energy,
so far as the bond dissociation is concerned. as compared to Single crystal
silicon. Al-though the Reaction  rate (Chemical Reaction) of the Si-F
species remains the same as in the case of Single crystal Silicon, but their
is a difference in the disorption rate of Si-F species from the top surface
of the feature to be etched. therefore, strained silicon can be etched
faster than Single crystal Silicon.

the deference in the desorption rate of Si-F byproducts can lead to the
non-uniformity in etching. this can be minimized by applying extra energy to
the ions during etching cycle of a typical BOSCH process, so that sputtering
coefficient got increased and hence minimize the non-uniformity..

In a typical BOSCH process this can be achieved by simply increasing the
platen power during the etch cycle along with Etch cycle time simultaneously.

Good Luck!

Manish Hooda
SCL India.