A method and device for reducing a dopant diffusion rate in a doped
semiconductor region is provided. The methods and devices include
selecting a plurality of impurity elements, including at least one dopant
element. Selection of a plurality of impurity elements includes selecting
a first impurity element with a first atomic radius larger than an
average host matrix atomic radius and selecting a second impurity element
with a second atomic radius smaller than an average host matrix atomic
radius. The methods and devices further include selecting amounts of each
impurity element of the plurality of impurity elements wherein amounts
and atomic radii of each of the plurality of impurity elements complement
each other to reduce a host matrix lattice strain.