MANUFACTURABLE DUV LITHOGRAPHY PROCESSES FOR 0.25-MU-M TECHNOLOGY CONTACT AND VIA LAYERS

One of the critical applications of DUV (248nm) lithography for 0.25 m u m technology is the imaging of contact and via holes. The goal of th is work was to demonstrate and verify manufacturing process capability for imaging 0.25 mu m design rule (300 nm) contacts and vias for inte gration into an existing process flow, including exposure on a first g eneration (NA=0.50, sigma=0.51) production capable DUV stepper. Furthe rmore, a simulation study was carried out to estimate the optimised op tical parameters for a next generation stepper with variable NA and Si gma. Finally, process latitudes for sub-300 nm contacts were measured and an estimate of minimum manufacturable contact sizes using conventi onal DUV lithography was made.