Fabrication of Silicon Nanopillar Teradot Arrays by Electron-Beam Patterning for Nanoimprint Molds

The critical issues that need to be considered during the fabrication of high-density nanostructures by e-beam lithography were reported. A 100-keV accelerating e-beam lithography tool and an inorganic e-beam resist of hydrogen silsesquioxane (HSQ) were employed to determine the resolution limit and to fabricate high-density and extremely small nanostructures. The processing steps required for the formation of the Si nanopillar array were e-beam lithography, resist development using 25% tetramethylammonium hydroxide (TMAH), Si etching by Cl2 plasma, and the removal of the remaining HSQ resist by dipping in HF. E-beam exposure was carried out with JEOL JBX9300FS equipment, with a beam radius of approximately 2 nm and an accelerating voltage of 100 KeV. The Si nanopillar arrays with pitch sizes larger than 30nm were fabricated successfully, whereas transfer of the resist pattern to the Si substrate at or below a 25-nm pitch.