Four high resolution negative electron beam resists are compared: TEBN-1 from Tokuyama Corp. Japan, ma-N 2401XP and mr-L 6000AXP from microresist technology GmbH Germany, and SU-8 2000 series from MicroChem Corp., USA. Narrow linewidth high density patterns are defined by 100 kV electron beam lithography, and the pattern is transferred into silicon by a highly anisotropic SF6/O-2/CHF3 based reactive ion etch process with a selectivity between silicon and the investigated resists of approximately 2.20 nm half-pitch lines and 10 nm lines with a pitch down to 60 nm are written and transferred into silicon. (c) 2006 American Vacuum Society.