Affiliation: | a Central Microstructure Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon. OX11 0QX., UK b GEC Plessey Semiconductors, Tamerton Road, Roborough, Plymouth, Devon. PL6 7BQ., UK |
Abstract: | Reduction of optical proximity effects (OPE), at deep uv wavelength of 248nm, caused by the variation of stepper lens operating conditions is investigated. It is shown that many of these effects, which increase as the Rayleigh limit is approached, can be minimised, and in many cases eliminated, by suitable choice of lens numerical aperture (NA) and partial coherence (sigma, σ). Application of these results should enable the user of advanced wafer steppers to carry out high resolution lithography with a minimum of time consuming optical proximity correction (OPC). |