Automated alignment and focusing system for nuclear microprobes

An automated approach is discussed for alignment and focusing in nuclear microprobes for otherwise manually controlled apertures. An adaptive convergent algorithm is developed to define the aperture sizes, locate the beam centroid and align the apertures with the optic axis of the focusing lenses. We show a focusing performance of 23 × 32 nm² for a 2 MeV H₂⁺ beam using the newly developed system coupled to the proton beam writing (PBW) line at CIBA. Fabrication of a 180 nm thick Au resolution standard using PBW is discussed towards achieving higher secondary electron collection efficiency using a multi-channel plate (MCP). A 30% enhancement in the collection efficiency is observed for Au grid compared to Ni resolution standards.