The performance of hydrogen silsesquioxane-based polymers (H-SiOx) as a spin-on negative resist for semiconductor lithography is unmatched by any other material. It is an inorganic resist with an established resolution below 10 nm, and resolutions are only limited by the electron beam spot size.  The high-resolution capability of the  H-SiOx resin is attributed to the small molecular size of its 3D framework. The polymer aggregates do not readily spread and entanglements are minimized leading to reduced linewidth variances. After e-beam exposure or EUV irradiation, it essentially turns to glass, and therefore has far superior resistance to the ion milling and etching steps when compared with standard polymer resists. It also has excellent mechanical strength, which means high-resolution structures can be defined with high aspect ratios of >20:1.