Realization of nanopillars on GaAs quantum well structure grown by molecular beam epitaxy

A double barrier heterostructure grown on a n(++) GaAs substrate by Molecul ar Beam Epitaxy (MBE) was used for the fabrication of random dot pillar arr ays of p-i-n quantum well nanoscale devices. The nanostructure was fabricat ed so as to get the vertical confinement of carriers within the undoped GaA s quantum well (QW) layer of 9 nm thick sandwiched between two Al0.33Ga0.67 As of 11 nm thick barrier layers using the conventional lithographic and Re active Ion Etching (RIE) techniques. The width of the pillars had the range of 10-50 nm and the height of the pillars varied from 185 to 250 nm by con trolling the etching time from 90 to 180 s, respectively. These nanopillars were characterized by the SEM and the nanoscale structure of the pillars w as studied by the Scanning Tunneling Microscope (STM) by applying a negativ e bias voltage of 3635 mV and the tunneling current of 2.61 nA. The light e mission was detected from the nanopillars when applying a forward bias volt age of 1.3 V at 4 K and the emitted light was observed at 830 nm. (C) 1999 Elsevier Science Ltd. All rights reserved.