Characterisation of Wet Chemical Etching of Algaas Layers Using Dynamic Optical Reflectivity

Abstract

ABSTRACTWet chemical etching of AlGaAs layers using a dilute mixture of ammonium hydroxide and hydrogen peroxide is monitored in real-time using dynamic optical reflectivity (DOR). The AlGaAs layers were grown as a multilayer reflector stack by chemical beam epitaxy (CBE). The reflectivity of a normal incidence 3 mW, 670 nm semiconductor diode laser is monitored during the etching process and analysis of the DOR trace gives the etch rate for the different etchant concentrations used.