Advanced i-line lithography for 0.5 mu m CMOS technology

A cost-effective 0.5 mu m lithographic capability has been developed using a reduction stepper with a 0.45 Na i-line lens and new photoresists. Resist processes provide excellent CD and sidewall angle control, with satisfactory exposure latitude. Resist pattern fidelity has been improved through computer-optimized reticle pattern modifications using serifs. Focus latitude has been significantly improved by application of new latent image metrology techniques. The authors provide an overview of these of other aspects and the lithographic process.<
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