Nanometer-scale resolution of a chloromethylated calixarene negative resist in electron-beam lithography: Dependence on the number of phenolic residues

We have investigated a chloromethylated calixarene, p-chloromethylmethoxcalix[n]arene (CMC[n]AOMe) (n=5,6,7), as a negative resist in electron-beam lithography. Each CMC[n]AOMe resist has a resolution of about 12 nm and a sensitivity of about 0.8 mC/cm2 which varies slightly with n (or molecular weight). A sub-10-nm Si wire has been fabricated by halide plasma etching and a CMC[n]AOMe resist as an etching mask. Because the resist pattern edge is smooth, Si wires with 7-nm width and 10-μm length were performed without any breaking.