Methods for selectively depositing an epitaxial layer are provided herein. In some embodiments, providing a substrate having a monocrystalline first surface and a non-monocrystalline second surface; exposing the substrate to a deposition gas to deposit a layer on the first and second surfaces, the layer comprising a first portion deposited on the first surfaces and a second portion deposited on the second surfaces; and exposing the substrate to an etching gas comprising a first gas comprising hydrogen and a halogen and a second gas comprising at least one of a Group III, IV, or V element to selectively etch the first portion of the layer at a slower rate than the second portion of the layer. In some embodiments, the etching gas comprises hydrogen chloride (HCl) and germane (GeH4).