The ability to split femtosecond free electron laser pulses and recombine them with a precisely adjustable delay has numerous scientific applications such as X-ray Photon Correlation Spectroscopy and X-ray pump X-ray probe measurements. A wavefront-splitting based hard X-ray split-delay system is currently under development at the Linac Coherent Light Source. The design configuration uses a series of Si(220) crystal reflections in the horizontal scattering geometry. It covers an energy range between 6.5 and 13 keV, a delay range from -30 ps up to 500 ps at 8 keV. The design features two planar air bearing based linear stage delay lines for improved stability and accuracy during the delay adjustments in order to maintain spatial overlap of the two branches during a delay scan. We present the basic design concept, tolerance analysis, and estimated performance of the system.
Optimum performance of a scanning photolithography tool is highly dependent upon the characteristics of its installation support system. Since the quality of the imaging product relies on precise control of the imaging process, vibration management is critical . Stiffness, mass, and inherent damping of the overall support system are the primary factors in determining whether the equipment is able to provide good process control under varied operating conditions. Current generation lithography scanners employ internal reaction forces to ultimately stabilize their optical exposure systems. These reaction forces are generated in order to counteract dynamic acceleration forces resulting from stages, wafer loaders and other devices and can transmit relatively large dynamic loads into the support system. In addition to withstanding the static weight of the tool, the support system must also resist these dynamic loads. Although there are several techniques for establishing the integrity of a support system, this paper will discuss a method for gauging how a system reacts dynamically to the loads generated by a scanning lithography tool. By computing the transfer function of acceleration divided by force, a dynamic measurement term called accelerance is used to quantify the integrity of the pedestal support system on which the tool resides.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.