The present invention discloses the use of edge-angle-optimized solid phase epitaxy for forming hybrid orientation substrates comprising changed-orientation Si device regions free of the trench-edge defects typically seen when trench-isolated regions of Si are recrystallized to the orientation of an underlying single-crystal Si template after an amorphization step. For the case of amorphized Si regions recrystallizing to (100) surface orientation, the trench-edge-defect-free recrystallization of edge-angle-optimized solid phase epitaxy may be achieved in rectilinear Si device regions whose edges align with the (100) crystal's in-plane directions.