Paper PS1+NS-WeM10
Parallel Writing of Complex Nanofeatures using Nanopantography

Wednesday, October 17, 2007, 11:00 am, Room 606

Nanopantography is a technique for massively parallel writing of nano-sized features. A broad-area, collimated, monoenergetic ion beam is directed to an array of sub-micron-diameter electrostatic lenses fabricated on a conductive substrate (e.g., doped Si wafer). By applying appropriate voltages to the lens electrodes, each "beamlet" entering the lens is focused to a spot on the wafer surface. The spot size can be up to 100X smaller than the diameter of the lens. With the choice of an Ar⁺ beam in the presence of Cl₂ gas, 10 nm-dia holes were etched in Si; while with the choice of a Ni⁺ beam, ~10 nm nickel dots were deposited on Si. Nanopantography has the capability to write arbitrary nano-sized features since the focal points can be displaced by tilting the substrate. A second-generation nanopantographic system was built to allow writing of complex nano-features. The improved system design had an ion flux ~ 15X higher than the first generation reactor. A LabView-controlled motorized stage could be tilted in both the X- and Y-axes with an accuracy of 0.011° degrees. This corresponds to translation of the focal point by 1.5 nm on the substrate. The energy distribution of the extracted ion beam was measured to have a spread of 2.2 eV, for a 100 eV beam. By continuously tilting the substrate in one direction, nanotrenches with ~15 nm (FWHM) width and ~40 nm depth were etched in a Si wafer. More complex patterns, such as letters of the alphabet, were also etched into Si in a massively parallel fashion by two-dimensional tilting of the substrate.