Chemical beam etching of InP in GSMBE

The Chemical Beam Etching Technique (CBET) of InP and GaAs based materials using Phosphorus or Arsenic chlorides in a ultra high vacuum growth chamber is on attractive method combined with CBE or GSMBE for complex device fabrication. Etching of a few monolayers up to more than one micron on a localized area followed by regrowth in the same ultra high vacuum chamber should produce nearly perfect interfaces and large application, in particular for the realisation of photonic and optoelectronic ICs. In this work, we investigated the controlled etching of InP by CBET using diluted PCl₃ in H₂ in a GSMBE growth chamber. We report on the etching rate of InP as function of PCl ₃ fluence and substrate temperature, the etched surface morphology and the profile at mask edges. We also demonstrate that in situ RHEED can be used during etching as an “atomic layer” precise end point detection