Interferometric Phase Shift Technique for High Resolution Deep UV Microlithography
Tittel, Frank K.
Cavallaro, Joseph R.
Smayling, Michael C.
Wilson, William L.
A new phase shifting technique based on interferometry has been developed which is especially suited for deep-UV microlithography. Using only a single layer chromium mask, with no additional phase shift elements, significant resolution and contrast enhancement over conventional transmission lithography can be achieved. Both computer simulations, as well as experiments using a CCD camera and UV photoresist confirm the capabilities of this new approach. Using a relatively simple experimental setup and an illumination wavelength of 355 nm, lines with feature sizes as find as 0.3 um were achieved.