Sub-50 nm template fabrications for nanoimprint lithography using hydrogen silsesquioxane and silicon nitride

The sub-50 nm templates are successfully fabricated using hydrogen silsesquioxane (HSQ) and silicon nitride on silicon substrate. The HSQ template is directly patterned by e-beam direct writing. The cured HSQ pattern is used for the template of nanoimprint process. The silicon nitride template is reactively ion etched by ZEP resist mask pattern which is prepared by e-beam direct writing using ZEP resist. The line widths of HSQ templates and ZEP patterns after developments are between 22-30 nm and 24-30 nm, respectively. The line width of silicon nitride templates without performing descum is same as that of the ZEP pattern but shows a rough surface. When plasma descum was performed before RIE, the line width of silicon nitride templates increased from 27 nm to 35 nm and has a clean surface. The HSQ template fabrication results in this study will be promise for sub-nm imprint process.