“MBE‐Litho”: 3 nm‐thick amorphous GaAs oxidized thin film functioning as highly sensitive inorganic resist for EB lithography and oxide mask for selective processes

Abstract

AbstractMolecular beam epitaxy (MBE) is one of the growth methods, which has been widely used for single crystalline semiconductor materials. In this study, we report a novel function of a 3 nm‐thick amorphous GaAs thin layer deposited using MBE at room temperature. Its oxidized region exposed to H2O‐vapor ambient works as a highly sensitive inorganic resist film for low‐energy electron‐beam (LE‐EB) lithography of 1‐5 keV. In this method, the surface area modified by LE‐EB direct writing provides a thermally stable oxide pattern, which can be directly applied to successive selective processes such as etching and growth under MBE environment. All the condition required for its selective etching/growth is to remove the background residual GaAs oxide of EB non‐irradiated area in the same UHV chamber. Thus, MBE gives the simplest and most efficient solution to all the processes including the resist film pre‐depositing, the background oxide removing and the successive etching/growth functions. We call this solution “MBE‐Litho ”. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)