SUB-10-NM MONOGRANULAR METALLIC LINES FORMED BY 200-KV ELECTRON-BEAM LITHOGRAPHY AND LIFT-OFF IN POLYMETHYLMETHACRYLATE RESIST

We report the reproducible fabrication of sub-10 nm lines by conventio nal 200 kV electron-beam lithography and lift-off of a granular gold f ilm on polymethylmethacrylate resist. We show that when the linewidth is smaller than 7 nm only one metallic grain can be formed in the widt h of the lines opened in the resist. The lines consisting of a chain o f 5-7 nm grains separated by 1-2 nm, have thus been called monogranula r lines. We demonstrate that these lines can be easily inserted betwee n metallic electrodes to produce single electron devices. Moreover, th e realization of very regular features at a sub-10 nm dimension range by a lift-oft. technique, sheds some light on the limitations usually encountered in the fabrication of continuous sub-10 nm metallic lines by lift-off.