The heavy ion micro-projection setup at Bochum

Abstract

A new type of microbeam setup is presented allowing MeV ion projection imaging of large area structures using the final lens of a high energy microprobe. Key issue of the new technology is the use of high aspect ratio high resolution stencil masks capable of withstanding high beam power which are now available. While the theoretical lateral resolution limit for this setup should allow the production of features well below 40 nm in size, the practical imaging resolution demonstrated so far is at 300 nm with heavy ions and typical implantation fluence. Microstructure formation is possible on substrates which do not allow the application of surface contact masks or in situations where such masks would result in sample contamination due to sputtering. A compact sample heater provides high substrate temperatures up to 1300°C during implantation for minimum damage implantation of crystalline samples. This setup opens a fascinating new field of applications in materials science since many structures can be exposed simultaneously. Fast structured implantation of stoichiometric doses of e.g. rare earth element ions gives access to the production of new materials of high purity at different substrate temperatures within reasonable time.