Methods of fabricating a semiconductor structure include implanting ion into a second region of a strained semiconductor layer on a multi-layer substrate to amorphize a portion of crystalline semiconductor material in the second region of the strained semiconductor layer without amorphizing a first region of the strained semiconductor layer. The amorphous region is recrystallized, and elements are diffused within the semiconductor layer to enrich a concentration of the diffused elements in a portion of the second region of the strained semiconductor layer and alter a strain state therein relative to a strain state of the first region of the strained semiconductor layer. A first plurality of transistor channel structures are formed that each comprise a portion of the first region of the semiconductor layer, and a second plurality of transistor channel structures are formed that each comprise a portion of the second region of the semiconductor layer.