We present a method for fabricating two-dimensional photonic crystal structures in high index materials, including amorphous silicon. The method is a two-step process, in which a perforated polymer membrane is first created using multilayer electron beam lithography, and then a high index material is deposited by sputtering. The result is a suspended dielectric slab with an array of holes, which acts as a planar photonic crystal. We present the fabrication process and structures realized with this method.