The fabrication of nanomesas and nanometal contacts by using atomic force microscopy lithography

The influence of preoxidation GaAs surface treatment over the atomic force microscopy-induced local anodic oxidation (LAO) is investigated in this paper. By immerging the GaAs samples into NaOH aqueous solutions, higher nano-oxides with better height distribution could be observed after LAO. The phenomenon is attributed to the hydrophilic surfaces obtained after the treatment such that higher local humidity and uniform water molecular distribution would be obtained on the GaAs surfaces, by using the higher nano-oxides with better height uniformity, nanomesas by using wet chemical etching, and nanometal contact after oxide lift-off are fabricated.