Electronic properties of etched-regrown heterostructure interfaces

Summary form only given. We establish an in-situ dry etching technique suitable to prepare complex semiconductor-heterostructures via molecular beam epitaxy (MBE) growth, in-situ etching and MBE regrowth. This technique enables us to fabricate novel structures, in particular, if combined with ex-situ lithography, quantum wires, dots and rings with very high confining potentials. Here we study the magneto-transport properties of two-dimensional electron systems (2DES) residing directly at an etched and regrown GaAs/AlGaAs interface. The electron mobility is extremely sensitive on the quality of the interface. The quantitative analysis of our transport data establishes that the interface roughness depends on the etching parameters. Varying the etching parameters from optimized conditions we create 2DES at GaAs/AlGaAs interfaces with tunable roughness. The far-infrared absorption exhibits a characteristic line splitting of the cyclotron resonance (CR), with its strength depending on the strength of the roughness.