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Dr. Peter Kuschnerus, Product Manager E-Beam Mask Repair Systems, LEO Electron Microscopy Group, Oberkochen,Germany

ABSTRACT

The quality of photo masks used in chip fabrication is a key factor determining the quality and yield achieved in wafer fabs. In order to achieve reduced feature sizes and to enhance integration depth, shorter wavelengths, i.e. 193nm and 157nm are used. Furthermore, advanced and complex enhancement techniques like optical proximity correction (OPC) features or phase-shift masks (PSM) are necessary. This results in challenging needs for advanced mask repair, in new materials, higher accuracies and precision and higher demands to VUV transmission. Whereas current mask-repair systems on the market are reaching their physical and technological limits, a new electron-beam-based mask-repair technology for current and future challenges has been developed. To evaluate this novel technique a beta tool has been delivered to a major semiconductor manufacturer. The novel technique of e-beam-induced chemical reactions has been especially developed for advanced photo-mask repair. It combines excellent focusing and non-destructive behaviour of ebeam and the selectivity of chemical reactions. It also meets the needs for advanced repair for future-generation masks such as EUV, EPL, or LEEPL.