Ion energy effect on surface amorphisation of semiconductor crystals

摘要

A new, low energy ion gun has been developed for use as a final step of TEM sample preparation by ion milling. The goal was to reduce the thickness of the amorphised layer formed on the bombarded surfaces. By decreasing the ion energy from 10 keV to 250 eV no amorphous surface layer was detectable on GaAs and only a 1 nm thick amorphous layer was found on Si, where the oxidation process complicates the phenomenon. The cross sectional technique was capable of revealing the surface roughening effect of the ion beam as well.