“…Among different etchant precursors, a wide number of chlorocarbons [2], HCl [3][4][5], and PCl 3 [6] have been successfully used under different etching conditions. More recently tertiarybutylchloride (TBCl) has been adopted first in a CBE [7,8] and later in a MOVPE reactor for the etching of In(GaAs)P materials [9,10]. TBCl is a very attractive etching precursor as it pyrolyses without side reactions in isobutene and isobutane and it is available in optograde purity since it is a starting reagent in the production of tertiarybutylphosphine and tertiarybutylarsine.…”