Wet Chemical Etch Solutions for Al x Ga1 − x P

This is the authors' abstract. We don't add key points for this paper.

Several wet etching solutions for AlGaP of different compositions have been studied. is found to etch in HF, , hyphosphorous acid , HCl, KOH, and 1% (MeOH). Etching of in HCl is reaction limited with an activation energy of ∼54.4 kJ/mol. At fixed conditions, the etch rates of vary exponentially with x in HF and HCl, while in 1% and mixtures of HCl and the etch rates follow a linear dependence on AlP mole fraction. HF has been found to be a good etchant for AlGaP over InGaP or AlInP with high selectivity, while HCl is useful for the reverse case. The use of 1% or the mixtures of HCl and provides little selectivity between AlGaP, InGaP, AlInP, and GaAs.