Patent attributes
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.