Abstract

For 0.25-μm lithography, the beam of x rays must display high spectral and spacial uniformity at the wafer plane. Synchrotrons provide a very stable and very well defined source of x rays. The small width of the electron beam (σ_x = 675μm and σ_y = 175μm —for ALADDIN operating at 800 MeV) acts as a point source, providing crisp images at the exposure plane roughly 2 m away. However, at a distance of 12 m a 1-in.-wide exposure field collects only 2.1 millirad of the available radiation. There are two ways to improve the incident power at the photoresist: shorten the line or install focusing elements. Installing focusing elements has the potential advantage of collecting x rays from a very wide aperture and providing an image that can be matched to the requirements of the exposure system. We will review the different types of beamlines proposed to date and discuss the advantages of this new design. The current status of the beam line being constructed at CXrL by using these optics will also be presented.

© 1990 Optical Society of America