February 2002 Meeting

 

Diode Pumped Nd:YAG Laser for X-Ray Lithography
Dr. Harry Rieger, JMAR
http://www.jmar.com

ABSTRACT: 300 watt table top diode pumped Nd:YAG laser system was developed for generating 25 W soft x-ray for lithography, and 75 nm feature size was demonstrated.

Laser generated plasma provides a unique soft x-ray point source for proximity lithography. For efficient x-ray generation, laser intensities of 1E15 W/cm2 on the target are needed. Focusing laser radiation on metallic targets for soft x-ray generation was demonstrated in the past with Q-switched operation at over 20 Joule per pulse level and low repetition rate. However, such a system generates large amounts of debris and has a poor x-ray dose control. At JMAR Research Inc. we have developed a new laser system that overcomes these issues by operating the laser at low energy per pulse and high repetition rate. We achieved record x-ray conversion efficiency by operating the laser at short pulse duration and high beam quality. These laser parameters are also attractive for efficient nonlinear processes, micro-machining applications, target ranging and more.

SPEAKER: Dr. Harry Rieger, is the creator of JMAR's BriteLight DPSS laser technology. He joined JMAR Research Inc. in 1994.

Prior to joining JMAR, Dr. Rieger was instrumental in the research and development of several new laser breakthroughs including an all solid state blue/green frequency agile laser, XeCl excimer laser Raman shifted in lead vapor cell, and Cesium atomic resonance receivers for the satellite to submarine laser communication.

Dr. Rieger received his doctorate in Electrical Engineering from the University of Illinois in 1982. He has over 40 papers in journals and conference publications, and holds thirteen laser associated patents with 3 more pending.