Pulse-width extending optical systems, projection-exposure apparatus comprising same, and manufacturing methods using same

摘要

This invention pertains to systems for extending the pulse length of pulsed sources of optical radiation. These systems reduce peak optical pulse power without reducing average optical power. The pulse-width extending systems split optical pulses into pulse portions, introduce relative delays among the pulse portions, and then redirect the pulse portions (or portions thereof) along a common axis. Such pulse-width extending systems are especially useful in projection-exposure apparatus for the manufacture of semiconductor devices where short wavelength, high power optical sources tend to damage optical components.