A new approach to the cap layer thinning of GaAs based heterostructures with near surface quantum wells

Low energy ion beam etching (IBE) at oblique angle at liquid nitrogen temperature has been applied for thinning of the cap layer of GaAs/InGaAs/GaAs (GaAs/AlGaAs/GaAs) heterostructures with near surface quantum wells (QWs) to study dielectric confinement effects [1]. It was shown that this etching provides the decreased radiation damage of such structures that results in smaller decreasing of photoluminescence (PL) quantum yield in comparison with other IBE techniques tested. This etching also saves a smooth surface of structures. Due to this fact the QW PL peaks are well defined and only slightly broadened even in a close approach to the QW layer position.