A Vacuum Spark Point Source for X-ray/EUV Lithography

摘要

The Vacuum Spark X-ray Source (VSX) embodies a miniature, high-repetition rate discharge emitting radiation in a broad spectrum optimized to emit soft X-rays with about 10 A wavelength. We have obtained over 100 μJ of energy per pulse in a narrow bandwidth centered around 7 A and pulse width less than 30 ns. The system operates with an ALFT proprietary pulser that yields a power output of 1 to 10 Watts of X-rays. A proprietary nested cone collimator is used to optimize the collection of the solid angle and direct parallel radiation towards the wafer. We predict this design will yield a throughput of 5 to 20 WLPH on 200 mm wafers. Presently, we are validating results obtained in the 1-5 WLPH range. ALFT's goal is to create an X-ray Point Source suitable for Next Generation Lithography. To date, two prototypes have been created to validate our theories and guide future development. The latest prototype has been designed to accept modifications to allow us to meet our 2001 performance goals. This year we achieved two major breakthroughs. We created a unique regenerating anode design that will enable thermal and debris management at the desired output levels, and we designed a trigger that ensures reliable discharge at repetition rates above 5 kHz. Following our previous SPIE Conference reports (SPIE Volume 3676-1, P. 410), the progress on the VSX Source is described here. Moreover, our technical roadmap is presented and the anode and trigger designs are disc losed.