Selective profile transformation of electron-beam exposed multilevel resist structures based on a molecular weight dependent thermal reflow
A. Schleunitz, V.A. Guzenko, A. Schander, M. Vogler and H. Schift
J. Vac. Sci. Technol. B29(6) (2011) 06F302; DOI: 10. 1016/j.mee.2010.12.046 (4pp)
Novel 3D resist structures are generated with both smooth slopes and stepped resist profiles on the same substrate and in very close vicinity. By performing gray-scale electron-beam exposure and development steps twice with different dose ranges, a selective transformation of multilevel structures into continuous slopes upon thermal treatment was enabled. The molecular weight dependence was analyzed and related to the locally different ability of the resist to flow, which enables one to selectively address resist structures which should be altered while others stay unaffected. The technique has large potential for prototyping elements and devices and can be used to fabricate stamps with complex 3D surfacepatterns for fabrication using nanoimprint.