<title>Contamination control during shipping, handling, and storage of reticles</title>

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This paper discusses state-of-the-art technology for controlling contamination and defects during shipping, handling, or storage of reticles. Reticles are used for printing IC patterns onto semiconductor wafers. In lithography process, defects in images are converted to wafers after each exposure, leading to classic failures such as short circuits or opens. Since a large batch of wafers might be processed before the defects are detected, high quality pattern images are very important for yield enhancement. Pattern defects can be created through particle deposition or damage of chrome lines due to Electrostatic Discharge (ESD) events. Airborne Molecular Contamination (AMC) may cause problems such as T- topping of photoresists or optics hazing which reduces image homogeneity and energy transmission. As the critical dimensions shrink to deep submicron regime, the susceptibility of reticle patterns to contaminant continuously increases. To meet increasingly stringent requirements of patterning technology, Reticle SMIF Pods (RSP) are developed. Reticles are encapsulated in the sealed pod to avoid particulate contamination in storage, as well as in manual or automatic transport. Constructed exclusively with static dissipative materials, the RSP provides effective protection for reticles from ESD-induced damage. Molecular contamination is minimized by carefully selecting construction materials. Equipped with an electronic data tracking/controlling device, the RSP can be integrated into OEM tools for automatic reticle management. With optional purge capability, the reticle environment is protected by chemically clean inert gas, which offers additional contamination control. These technologies are extensively discussed in this paper. Design principles and experimental data that support performance evaluations of RSP are presented.