Capability of 70 nm Pattern Replication in X-Ray Lithography

The 70-nm-node basic patterns were replicated by X-ray lithography using a very high contrast resist UV6SL and a low contrast X-ray mask. A simultaneous replication of 70 nm isolated line and 70-nm-L/S pattern was fairly demonstrated in the gaps of 10 and 12 µm. The 80 nm dense and semidense contact hole (C/H) patterns were also successfully replicated in the same gaps. Aerial image calculation supported these experimental results. From the comparisons with F 2 lithography that requires very high numerical aperture (NA), phase shift masks (PSMs), optical proximity correction (OPC), and resolution enhancement techniques (RETs) to attain the 70 nm node, it has been shown that using proximity X-ray lithography (PXL) it is much easier to realize the 70 nm node.