A Chemically Amplified Fullerene-Derivative Molecular Electron-Beam Resist

Current lithographic resists depend on large polymeric materials, which are starting to limit further improvements in line‐width roughness and feature size. Fullerene molecular resists use much smaller molecules to avoid this problem. However, such resists have poor radiation sensitivity. Chemical amplification of a fullerene derivative using an epoxy crosslinker and a photoacid generator is demonstrated. The sensitivity of the material is increased by two orders of magnitude, and 20‐nm line widths are patterned. A sensitive resist: Molecular resists based on small nonpolymeric molecules promise improvements in lithographic performance over conventional resists. Typically, molecular resists are capable of high resolution at the expense of sensitivity. A fullerene‐based molecular resist (see scheme) shows significantly enhanced sensitivity when chemically amplified by a method based on epoxy crosslinking.