Technologies for Nanoscale Imaging Using Coherent Extreme Ultraviolet and Soft X-Ray Light

ABSTRACT: Microscopy is a critical enabling technology for advancing our understanding of nature. Imaging nano-scale objects with light in the extreme ultraviolet (EUV) and soft x-ray regions of the spectrum has advantages over visible light for several reasons including: resolution, elemental specificity, and the ability to image internal structures. Coherent diffractive imaging (CDI) has been developed as a tool to circumvent the limitations of currently available x-ray optics. In recent years CDI has shown very high, near-wavelength resolution when used with EUV light from high harmonic up-conversion from ultrafast lasers. We propose to develop a complete tabletop EUV microscope instrument that is tunable in wavelength from 30 to 2.5nm (40 to 500 eV). The key to creating a practical instrument will be developing a driving laser that is specifically tailored to high harmonic generation and is phase matched over this entire wavelength range, while requiring little alignment and maintenance. In Phase II we will continue our Phase I effort by designing an ultrashort amplifier based on Cr:YAG for the fiber laser developed in Phase I. Together, these technologies constitute a microscope with broad application in basic research, materials studies, lithography and medicine. BENEFIT: The microscope developed under this program will have broad application in basic research, materials studies, lithography and medicine. It will have the capability to perform actinic mask inspection for semiconductor lithography at 13.5nm. The ability to image thick samples and the inherent elemental contrast of the "water-window" region of the x-ray spectrum, will allow this microscope to image whole unstained cells without the need for sectioning with a resolution of 10nm or better. This microscope and its necessary driving technologies should find broad commercial market in addition to the DoD needs for nano-materials identification and battlefield medicine.