Nanoscale devices fabricated by direct machining of GaAs with an atomic force microscope

摘要

We demonstrate a lithography wherein the tappingmode of an atomic force microscope the Si tip is used as achiseling tool for direct machining of a GaAs surface. Single-groove drawing movements in a vector-scan mode result inapproximately 3-4 nm deep and 30 nm wide furrows, which can becombined to arbitrary noncontiguous polygon patterns. Beneathsuch a groove a barrier arises in the electron channel of aGaAs/AlGaAs modulation-doped filed effect transistor(MODFET). Using appropriate sub-100 nm line patterns weprepared quantum point contacts and single electron devices. At T= 4.2 K the transconductance characteristics of these nanoscaleMODEFT's exhibit structures, which represent signatures of eitherthe quantized conductance or Coulomb-blockade effects. 2000Elsevier Science B.V. All rights reserved.