Interaction of High Resolution Field Ion Probes with Materials

Ion beam lithography IBL can be expected to have significant advantages over electron beam lithography EBL. The ions deposit much more energy per charged particle and thus resists are typically 50-100 times more sensitive to ions than to electrons. Also the range of the ions is well defined by their incident energy and there is no backscattering that causes the proximity effects which are a serious limitation in electron beam lithography. This means that very high resolution configurations could be structured by direct write ion beam lithography using single resist layers on thick substrates. It is our task to develop the instrumentation required to produce high resolution, high current density probes that could be used to investigate the interactions of ions with resists and substrate materials, evaluate the potential and feasibility of ion beam lithography and produce structures and devices with dimensions in the range of 10 to 100 nm. Our approach and the instrumental developments that we have made are based on the use of the H2 gaseous field ion source that we have developed. This source represents an important breakthrough in providing a very high brightness ion beam of low mass ions, H2, with high angular current density and low energy spread.