Short-period surface superlattices formed by plasma etching
We report the development of a process for fabricating etched surface superlattices (SSL). We utilize low-voltage electron cyclotron resonance plasma etching in conjunction with electron beam lithography to form a short-pitch grating relief on GaAs/AlGaAs heterostructures hosting a high-mobility two-dimensional electron gas (2DEG). The process minimizes damage to the 2DEG and results in highly uniform etched gratings. A Schottky gate covering the etched surface appears to improve the electrical properties of the SSLs. Magnetotransport measurements show the effectiveness of this technique in realizing high-quality SSLs with periods down to 100 nm.