BASIC MECHANISMS OF AN ATOMIC-FORCE MICROSCOPE TIP-INDUCED NANO-OXIDATION PROCESS OF GAAS

An atomic force microscope (AFM) tip-induced direct nano-oxidation pro cess of GaAs(100) substrates has been investigated, and is viewed as a promising method for the fabrication of nanometer-scale electronic de vices such as single electron tunneling transistors. The effects of th e AFM drawing parameters such as tip bias voltage and writing speed as well as the ambient humidity on the oxide line height and width were explored. The rate of reaction and its dependence on electric field st rength and oxide thickness were examined to understand the basic mecha nisms involved in the tip-induced oxidation of GaAs. The rate of oxida tion/anodization was found to decrease rapidly with oxide film growth, which was explained at the simplest level in terms of a self-limiting influence of decreasing electric held strength. (C) 1998 American Ins titute of Physics.