Photonic crystal (PhC) slabs with a lower-index material surrounding the core layer are an attractive choice to circumvent the drawbacks in the fabrication of membranes suspended in air. In this chapter, we summarize and expand a numerical study performing a design protocol for nanophotonic devices based on an oxide-cladding aluminum nitride PhC slab. We show the design of an ideal structure and analyze the effects of material dispersion based on a first-order correction perturbation theory approach, in which the dielectric functions obtained by experimental measurements of the thin film materials were employed. This bulk PhC slab was then used as a host medium for the study of an optimized nanocavity, as well as for the development of a slow light waveguide that can compose a Mach-Zehnder electro-optic modulator. The study also includes modeling and analysis of the effects of fabrication-induced disorder, such as deviation in sizes and positions of holes, in the performance of the photonic devices. The results show that the oxide-cladding AlN PhC can be a promising platform for the development of integrated photonic devices.