Pulse-width extending optical systems, projection-exposure apparatus comprising same, and manufacturing methods using same
AssigneeNikon Corporation
InventorYuji Kudo
Life of this patent
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Abstract
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.
Claims29
A light source apparatus comprising:
- a light source unit supplying a light pulse having a wavelength not more than 193 nm;
- and
- a pulse-width extending optical system arranged in an optical path of the light pulse supplied from the light source unit, which extends a duration of the light pulse supplied from the light source unit while decreasing a peak power of the light pulse, the pulse-width extending optical system including an optical surface having a multi-layer coating to divide the light pulse into at least two light pulses.
A light source apparatus comprising:
- a light source unit supplying a light pulse having a wavelength not more than 193 nm;
- and
- a pulse-width extending optical system arranged in an optical path of the light pulse supplied from the light source unit, which extends a duration of the light pulse supplied from the light source unit while decreasing a peak power of the light pulse, the pulse-width extending optical system including a polarizing beam splitter to divide the light pulse into at least two light pulses.
A light source apparatus comprising:
- a light source unit supplying a light pulse having a wavelength not more than 193 nm;
- and
- a pulse-width extending optical system arranged in an optical path of the light pulse supplied from the light source unit, which extends a duration of the light pulse supplied from the light source unit while decreasing a peak power of the light pulse, the pulse-width extending optical system including a beam converting member changing a polarized beam condition.
A light source apparatus comprising:
- a light source unit supplying a light pulse having a wavelength not more than 193 nm;
- and
- a pulse-width extending optical system arranged in an optical path of the light pulse supplied from the light source unit, which extends a duration of the light pulse supplied from the light source unit while decreasing a peak power of the light pulse, the pulse-width extending optical system including a light split member having a light split surface with a reflectance R such that 29.3%<R<50% or a transmittance T such that 29.3%<T<50%.
Dependencies are inferred from the claim text.