Cr/Ni多層膜のSIMS分析における深さ分解能に及ぼすイオン照射条件の影響

抄録

The effect of ion bombardment conditions on depth resolution in a Cr/Ni thin multilayer sample has been studied using the secondary ion mass spectrometer (SIMS).
The depth resolution is improved either with increasing mass or with decreasing velocity of primary ions. The resolution is mainly related to surface roughness which is induced by ion bombardment. The surface roughness was reduced in the case of low velocity cesium ion bombardment comparing with other ion species such as argon, nitrogen and oxygen. In oxygen ion bombardment, the resolution was extremely deteriorated at the interface from nickel to chromium, due to the selective sputtering phenomena in the nickel layer.
Furthermore, the presence of hydrogen compound having high electron affinity at the interface complicates the interpretation of depth profile due to the change of positive secondary ion yield. To prevent the change in the yield, it has been considered that the bombardment of ion species having high electron affinity is very useful.