SUBMICRON OPTICAL LITHOGRAPHY BASED ON A NEW INTERFEROMETRIC PHASE-SHIFTING TECHNIQUE

This paper reports the computer simulation and experimental demonstration of a new phase shifting technique based on interferometry that is especially suited for deep ultraviolet (UV) microlithography. Significant resolution and contrast enhancement can be achieved using a chrome binary mask. Image analysis based on charge coupled device (CCD) detection and patterns recorded in UV photoresist has been used to study the capabilities of this new approach. Lines with a feature size as fine as 0.3 mu m have been demonstrated using 355 nm illumination.