Table of Contents
Physics Research International
Volume 2012, Article ID 249495, 11 pages
http://dx.doi.org/10.1155/2012/249495
Research Article

Development of Laser-Produced Tin Plasma-Based EUV Light Source Technology for HVM EUV Lithography

1EUV Development Division, Gigaphoton Inc., 400 Oaza Yokokurashinden Oyama-shi, Tochigi-ken 323-8558, Japan
2EUV Development Division, Gigaphoton Inc., 3-25-1 Shinomiya Hiratsuka-shi, Kanagawa-ken 254-8555, Japan

Received 10 May 2012; Accepted 20 June 2012

Academic Editor: Sergi Gallego

Copyright © 2012 Junichi Fujimoto et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Since 2002, we have been developing a carbon dioxide (CO2) laser-produced tin (Sn) plasma (LPP) extreme ultraviolet (EUV) light source, which is the most promising solution because of the 13.5 nm wavelength high power (>200 W) light source for high volume manufacturing. EUV lithography is used for its high efficiency, power scalability, and spatial freedom around plasma. We believe that the LPP scheme is the most feasible candidate for the EUV light source for industrial use. We have several engineering data from our test tools, which include 93% Sn ionization rate, 98% Sn debris mitigation by a magnetic field, and 68% CO2 laser energy absorption rate. The way of dispersion of Sn by prepulse laser is key to improve conversion efficiency (CE). We focus on prepulsed laser pulsed duration. When we have optimized pulse duration from nanosecond to picosecond, we have obtained maximum 4.7% CE (CO2 laser to EUV; our previous data was 3.8%) at 2 mJ EUV pulse energy. Based on these data we are developing our first light source as our product: “GL200E.” The latest data and the overview of EUV light source for the industrial EUV lithography are reviewed in this paper.