We investigated systematically chemical beam etching of GaAs, GaInP and AlInP using a novel precursor, tertiarybutylchloride (TBCl). Because TBCl is not corrosive to the growth system and has long-term stability at room temperature, it is a promising alternative to AsCl3 or AsBr3 from the viewpoint of safety. Layer-by-layer etching was achieved as evidenced by intensity oscillations in reflection high-energy electron diffraction. While a slightly higher substrate temperature around 550 degrees C is necessary, pre-cracked TBCl may be applicable in in situ etching for III-V semiconductor device fabrication.