The aim of this research is to explore the mechanisms of strengthening in single-crystal nitride superlattices. The shape, amplitude, direction, and lattice mismatch of the composition modulation are variables. Superlattices are grown by sputter deposition and characterized using X-ray diffraction, transmission electron microscopy, and Auger spectroscopy. Nanoindentation is used to measure hardness, and models are developed for hardening based on dislocation motion through the layered structures. %%% The understanding gained from this research could be used for controlling process variables to tailor mechanical properties in thin films.