In-Situ Monitoring Of Etch By-Products During Reactive Ion Beam Etching Of Gaas In Chlorine/Argon

Abstract

AbstractMass spectrometry of the plasma effluent during Reactive Ion Beam Etching (RIBE) of GaAs using an Inductively Coupled Plasma (ICP) source and a Cl2/Ar gas chemistry shows that AsCl3, AsCl2 and AsCl are all detected as etch products for As, while GaCl2 is the main signal detected for the Ga products. The variation in selective ion currents for the various etch products has been examined as a function of chuck temperature (30–100°C), percentage Cl2 in the gas flow, beam current (60–180 mA) and beam voltage (200–800 V). The results are consistent with AsCl3 and GaCl3 being the main etch product species under our conditions, with fragmentation being responsible for the observed mass spectra.