Cutting of 20A holes and lines in metal-β-aluminas

Holes 20A in diameter and fine lines 20A wide can be cut in the metal-β-aluminas using the 10A electron beam of the Vacuum Generators, HB5 scanning transmission electron microscope. The minimum current density required for cutting was 103 amp/cm2. Electron energies of 40, 60, 80, and 100 keV were used. In the case reported here, uniform 20A holes and lines were cut through self-supporting 1000A thick slabs of sodium-β-alumina to provide very high electron contrast. Once cut, the β-aluminas are stable and will tolerate exposure to air without degradation of the electron cut patterns. They may be used directly as masks (eg. for ion implantation). They could probably be cut on the substrate with no damage to the underlying material. These specimens, once cut, can be removed from the microscope and stored, then returned for further cutting or viewing. 6 references, 3 figures