Nanoscale oxidation of GaAs-based semiconductors using atomic force microscope

Fundamental results obtained in an atomic force microscope (AFM) direct nanoscale oxidation process are presented, which is regarded as a simple method for fabricating nm-scale devices such as single electron tunneling transistors and quantum effect electronic devices. Using Au-coated Si cantilevers, we have succeeded in drawing nm-scale oxide lines in GaAs-based semiconductor surfaces; n+-GaAs(100) and self-assembled InGaAs quantum dots grown by molecular beam epitaxy on GaAs(100) substrates. The effects of AFM drawing parameters such as tip bias voltage and writing speed on oxide linewidth and height have been explored. GaAs oxide lines as narrow as ∼40 nm have been patterned by this technique.