Hydrogen silsesquioxane (HSQ): a perfect negative tone resist for developing nanostructure patterns on a silicon platform

This paper reviews the development of hydrogen silsesquioxane nanostructures (sub-100nm) on a silicon platform. The effect of HSQ resist in thick (128nm thick resist) and thinner state (30nm thick resist) has been demonstrated and minimum possible structures with these are discussed in details. Most applicable structures like straight lines/spaces, sharp joints/corners and dots were developed to investigate the effects of development time on the lithography properties of HSQ. Soft bake after spinning process had been avoided in view of achieving better contrast and stable resist deposition. We had also reached to a conclusion that increasing the development time could improve resist contrast and pattern resolutions up to certain limits but may vary with type of structures and other conditions.