High resolution organic resists for charged particle lithography

Exposure of resist with electron or ion beams is a common nanolithography technology which is used to fabricate electronic devices and microstructures. The resolution mainly depends on the beam size and the resolution of the resist. We have developed two new high resolution organic resists, which are calixarene derivatives. 50 keV electron beams and 260 keV $Be2+$ ion beams were used to expose the resist, and 10 nm resolution was achieved with the Gaussian electron beam. The electron beam sensitivities of the two resists were 7 and 0.7 mC/$cm2.$ By using them, we produced 10-nm-order resolution patterns, which we exposed with a Gaussian electron beam. We also achieved 10-nm-level resolution by using a low molecular weight (Mw=1100) polystyrene resist, almost the same Mw as that of the calixarene. The resolution of the polystyrene resist improved as lower molecular weights were used. Therefore, the resist resolution depends on the molecular weight or molecular size.