The dark side of Helium Ion Microscopy

Defects are an unavoidable side product of Helium Ion Microscopy (HIM). Several studies have investigated the creation and fluence dependence of the ion beam related damage to the specimen. Here, I want to present results of defect related investigations obtained with an ultra high vacuum HIM.
I will show examples of very small doses as low as 1×1012 cm−2. Such doses were used to investigated the quenching of ionoluminescence (IL) in semiconductors. It turns out that the quenching is not only material dependent but also sensitive to the size of the specimen.
IL has further been used to create luminescence bulk patterns and measure the surface projected interaction volume of the beam with ionic crystals.
At higher doses the well known bubble and blister formation is observed. We studied this effect for Gold and estimated He pressures from several 100MPA up to a few GPa. At even higher doses selforganized nanostructures are formed on metal surfaces. First results of a temperature and material dependent investigation with fluences up 1×1024 m2 will be shown.
This research is supported by the Dutch Technology Foundation STW, which is the applied science division of NWO, and the Technology Programme of the Ministry of Economic Affairs.