Submicron patterning of Nb using CF3Br and a single layer resist

Abstract

A simple technique is described to fabricate submicron patterns in Nb films. Typical aspects are the use of a single layer PMMA mask and CF3Br as an etchant. Trenches with a width of less than 100 nm and very steep sidewalls have been obtained in a 200 nm thick Nb film. Etch rates for Nb, Nb2O5 and PMMA are given. It is shown that the RIE process is dominated by chemical etching.