Embodiments provided herein describe antireflective coatings and methods for forming antireflective coatings. A substrate is provided. A first antireflective layer is formed over the substrate. The first antireflective layer has a first refractive index. A second antireflective layer is formed on the first antireflective layer. The second antireflective layer has a second refractive index. The first antireflective layer and the second antireflective layer jointly form an antireflective coating. The antireflective coating is graded such that the antireflective coating comprises at least three sub-layers, each of the at least three sub-layers having a unique refractive index.