Kla Corporation

Will Schumaker

Michael Friedmann

Chao Chang

Jongjin Kim

Ben Clarke

Methods and systems for generating X-ray illumination from a laser produced plasma (LPP) employing a low atomic number, cryogenic target are presented herein. A highly focused, short duration laser pulse is directed to a low atomic number, cryogenically frozen target, igniting a plasma. In some embodiments, the target material includes one or more elements having an atomic number less than 19. In some embodiments, the low atomic number, cryogenic target material is coated on the surface of a cryogenically cooled drum configured to rotate and translate with respect to incident laser light. In some embodiments, the low atomic number, cryogenic LPP light source generates multiple line or broadband X-ray illumination in a soft X-ray (SXR) spectral range used to measure structural and material characteristics of semiconductor structures. In some embodiments, Reflective, Small-Angle X-ray Scatterometry measurements are performed with a low atomic number, cryogenic LPP illumination source as described herein.

Laser produced plasma illuminator with low atomic number cryogenic target

Methods and systems for generating X-ray illumination from a laser produced plasma (LPP) employing a liquid sheet jet target are presented herein. A highly focused, short duration laser pulse is directed to a liquid sheet jet target. The interaction of the focused laser pulse with the sheet jet target ignites a plasma. In some embodiments, the liquid sheet jet is generated by a convergent capillary nozzle or a convergent, planar cavity nozzle. In some embodiments, the target material includes one or more elements having a relatively low atomic number. In some embodiments, the liquid sheet jet LPP light source generates multiple line or broadband X-ray illumination in a soft X-ray (SXR) spectral range used to measure structural and material characteristics of semiconductor structures. In some embodiments, Reflective, Small-Angle X-ray Scatterometry measurements are performed with a liquid sheet jet LPP illumination source as described herein.

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Capitola, CA, United States of America

Will Schumaker