The Back-Side Morphology of LPE-Grown AlGaAs/GaAs/AlGaAs Heterostructures after the Complete Removal of the GaAs Substrate by Selective Etching

As-grown surfaces of AlGaAs/GaAs/AlGaAs heterostructures were stuck down the glass disks and after that the GaAs substrates were removed completely by selective chemical etching. As a result the back-surface of the heterostructures became open to light. The influence of different factors on the back-surface planarity and on the density of such specific defects as holes in the GaAs layer have been investigated. It is shown that the density of holes can be decreased to a value less than 1 hole/cm² if a glove-box maintained under a pure N₂ atmosphere and connected with LPE installation is used.