Interactions between H2 and N2 plasmas and a GaAs(100) surface: Chemical and electronic properties

Publisher Website
Google Scholar
Abstract
The existence and possible origin of surface states on GaAs surface exposed to an N2 plasma have been studied on surfaces cleaned by H2 plasma in a UHV system. The H2 plasma is shown to be very effective in reducing the C and N concentrations at the surface and to a lesser extent, the O concentration. A subsequent heating around 530 °C removes the remaining oxygen and gives a clean surface. The interaction of these clean surfaces with an N2 plasma shows a two‐time constant behavior: (i) a rapid (5 s for our experimental conditions) dielectric (nitride) formation associated with an increase of the work function; (ii) a slow (∼100 s) decrease of the surface photovoltage and of As concentration at the surface. Comparison of n‐ and p‐type samples seems to indicate that this is due to a reduction of the band bending depending on the final As concentration.

This publication has 3 references indexed in Scilit: