Inverse Compton Source for Extreme Ultraviolet Lithography

Extreme Ultraviolet Lithography (EUVL) is a critical emerging technology to enable fabrication of integrated circuit with sub-20 nm features. However, the implementation and wider adoption of EUVL is limited by the lack of compact, tunable, narrow-band, directional high power sources in the EUVL wavelength range. The present state-of-the-art for EUV R & amp;D is plasma based sources at 13.6 nm that are not directional, require frequent repair, and are not easily scalable to shorter wavelengths. This project seeks to address this problem by developing a high duty cycle Inverse Compton Scattering (ICS) source, based on the scattering of a re-circulated/re-amplified 10 m laser off a multi-bunch train electron beam produced by a photoinjector in a novel active multi-pass intracavity. In Phase I, a thorough design study of a re-circulated ICS experiment at ATF BNL has been conducted. All system components have been specified for implementation in Phase II. The most risky aspect of the Phase I design study was demonstrating the feasibility of CO2 pulse re-amplification at 25-ns intervals with the equipment presently available at the ATF BNL (4 atm. amplifier). This milestone was successfully accomplished through in depth numerical simulation of the amplifier media performance in a pulse train regime. An unexpected finding was overall ICS system improved performance at longer laser pulses. In Phase II, a scaled demonstration experiment of re-circulated ICS will be carried out at the Accelerator Test Facility at BNL. If successful, the output would substantially increase prospects of commercialization and long overdue market acceptance of ICS based compact light sources. Commercial Applications and Other Benefits: The primary application targeted by the proposed system, Extreme Ultraviolet Lithography (EUVL), is on the cusp of becoming a billion-dollar industry; but, one for which the current EUV sources are inadequate for the full range of manufacturing processes and diagnostics. The technology scales well to the X-ray range, where there are a number of other medical and industrial applications.