Nanolithography and nanofabrication using hydrogen silsesquioxane resists

Tremendous interest in nanotechnology has required versatile patterning tools for the fabrication of nanometer-scale structures with high precision and electron-beam lithography (EBL) has been widely used for this purpose. Hydrogen silsesquioxane (HSQ) has received much attention as a new class of negative-tone electron-beam resist. Due to its high resolution and excellent etch resistance, HSQ resist has proven to be very useful in various nanofabrication processes. The focus of this thesis has been on the development of EBL processes and the investigations of material aspects of HSQ resists. For resolution enhancement, the effects of developer temperatures and substrates have been examined. By increasing resist contrast or reducing the effects of backscattered electrons, high quality of ultra-dense nanostructures have been realized. The changes in chemical structures and properties of thermally cured and electron-beam-exposed HSQ films have been characterized to achieve the optimized processing. Development characteristics and etching properties have been comparatively studied. Furthermore, spatial characterization has been performed to identify chemical reactions in HSQ resists during electron-beam exposure. As a possible application of HSQ nanostructures, triangular nanochannels fabricated using the resists collapse technique have been demonstrated.