Improvements in the fabrication of integrated circuits are driven by
the decrease of the size of the features printed on the wafers. Current lithography
techniques limits have been extended through the use of phase-shifting masks, off-axis
illumination, and proximity effect correction. More recently, liquid immersion
lithography has been proposed as a way to extend even further the limits of optical
lithography. This invention described a methodology based on contact printing using
a projection lens to define the image of the mask onto the wafer. As the imaging
is performed in a solid material, larger refractive indices can be obtained and
the resolution of the imaging system can be increased.