Electron-beam-assisted etching of CrOx films by Cl2

Based on analysis by in situ Auger electron spectroscopy, partially oxidized Cr films, 3–10nm thick, were etched by the combination of 2keV electrons and Cl2(g). The Cl2 gas pressure in the area irradiated by the e beam is critical and must be in the mTorr regime. For the flux (8mAcm−2) of electrons used, the etching rate saturated for estimated local Cl2 pressures above 2mTorr. The effects on etching of small amounts of Si are described.