Embodiments described herein generally relate to improved methods and solutions for cleaning a substrate prior to epitaxial growth of Group III-V channel materials. A first processing gas, which includes a noble gas and a hydrogen source, is used to remove the native oxide layer from the substrate surface. A second processing gas, Ar/Cl2/H2, is then used to create a reactive surface layer on the substrate surface. Finally, a hydrogen bake with a third processing gas, which includes a hydrogen source and an arsine source, is used to remove the reactive layer from the substrate surface.