Electron Beam Lithography Patterning of 50 nm Trenches and Islands on PMMA

Growth of patterned semiconductor nanostructures is important for development of semiconductor nanodevices. Nanostructures are fabricated using either top down or bottom up approach. In top down approach the nanostructures are obtained by trimming down a bulk semiconductor whereas bottom up approach selectively adds atoms to create nanostructures. Different type of patterning is required for both the strategies. For top down approach substrates are patterned using lithography in such a manner that islands of resist are created so that they can be used as masks whereas bottom up approach requires holes to be patterned on substrates so that nanostructures can be selectively grown in the holes. This paper discusses the processes both for patterning of 50 nm islands as well as trenches in PMMA using electron beam lithography.