Bulk quantities of single-crystal silicon micro-/nanoribbons generated from bulk wafers

This Letter demonstrates a strategy for producing bulk quantities of high quality, dimensionally uniform single-crystal silicon micro- and nanoribbons from bulk silicon (111) wafers. The process uses etched trenches with controlled rippled structures defined on the sidewalls, together with angled evaporation of masking materials and anisotropic wet etching of the silicon, to produce multilayer stacks of ribbons with uniform thicknesses and lithographically defined lengths and widths, across the entire surface of the wafer. Ribbons with thicknesses between tens and hundreds of nanometers, widths in the micrometer range, and lengths of up to several centimeters, can be produced, in bulk quantities, using this approach. Printing processes enable the layer by layer transfer of organized arrays of such ribbons to a range of other substrates. Good electrical properties (mobilities similar to 190 cm(2)V(-1)s(-1), on/off > 10(4)) can be achieved with these ribbons in thin film type transistors formed on plastic substrates, thereby demonstrating one potential area of application.