Vertical etch heterolithic integrated circuit devices are described. A method of manufacturing NIP diodes is described in one example. A P-type substrate is provided, and an intrinsic layer is formed on the P-type substrate. An oxide layer is formed on the intrinsic layer, and one or more openings are formed in the oxide layer. One or more N-type regions are implanted in the intrinsic layer through the openings in the oxide layer. The N-type regions form cathodes of the NIP diodes. A dielectric layer deposited over the oxide layer is selectively etched away with the oxide layer to expose certain ranges of the intrinsic layer to define a geometry of the NIP diodes. The intrinsic layer and the P-type substrate are vertically etched away within the ranges to expose sidewalls of the intrinsic layer and the P-type substrate. The P-type substrate forms the anodes of the NIP diodes.