Relationship between X-ray Intensity and Electric Bias on Al2O3 Surface during Low Energy Ga+ Irradiation

Low-energy characteristic X-ray emission is detected during bombardment of positive low energy ions onto insulator materials. The phenomenon is considered to be related to surface charge-up. To study further the mechanism, the characteristic X-rays was studied during 30 keV Ga+ ions bombardment onto Al2O3 monocrystalline specimens applied with a direct current (DC) bias in the present work. The applied DC voltage builds an electric field parallel to the surface of the specimen. The results show that the characteristic X-rays of O-K(alpha) and Al-K(alpha) increased with the increasing of the applied DC voltages.