Auger electron spectroscopy electron‐beam induced damage of a H2O‐covered Si(100) surface

Abstract

The effect of 2‐keV electron‐beam irradiation on H2O adsorbed onto a Si(100) single crystal at 300 K was studied using Auger spectroscopy. The incident electron beam induces surface oxidation exclusively in the region irradiated as indicated by measurements of the lateral composition profile. Oxidation ceases when the broad SiLVV Auger peak extending from 74 to 83 eV is ≊5 times higher than the peak at 91 eV, a process which requires ≊80‐L H2O exposure (pH2O=1.3×10−7 mbar) using normal beam incidence. The oxygen atomic fraction at this point is ≊0.82. After 15 h at 300 K, the ratio of the normalized peak‐to‐peak signals at 78 and 511 eV is 1:1. A focused beam of 2‐keV 1‐mA emission (≊20‐μA sample current) in the absence of water is capable of destroying the oxide layer, practically recovering the clean surface after 1 h. Annealing at 800 K has little effect on the oxide. Depth profiling by Ar+ bombardment indicates that the thickness of the oxide film is ≊1.0 nm.