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Surface relief associated with isothermal tetragonal-to-monoclinic phase transformation, i.e., martensitic transformation, in zirconia-3mol yttria (PSZ) with and without alumina addition, which occurred during aging at 130°and 200°C in air or vacuum environment was observed by an atomic force microscopy. The surface relief occurred from grain boundaries into grain interiors as the aging time increased and then spread succsessively into the surrounding grains with further aging. However, alumina particles and cubic phase paricles in PSZ containing alumina acted as obstacles for the advance of transformation, which would be the major reason for the improved mechanical properties of PSZ by the addition of alumina.

Extreme ultraviolet lithography is a powerful tool for printing features of 0.1 micro m and below; in Japan and the USA there is a growing tendency to view it as the wave of the future. With Schwarzschild optics, replication of a 0.05 micro m pattern has been demonstrated in a 25 micro m square area. With a two-aspherical-mirror system, a 0.15 micro m pattern has been replicated in a ring slit area of 20 mm x 0.4 mm; a combination of this system with illumination optics and synchronized mask and wafer stages has enabled the replication of a 0.15 micro m pattern in an area of 10 mm x 12.5 mm. Furthermore, in the USA, the Sandia National Laboratory has succeeded in fabricating a fully operational NMOS transistor with a gate length of 0.1 micro m. The most challenging problem is the fabrication of mirrors with the required figure error of 0.28 nm. However, owing to advances in measurement technology, mirrors can now be made to a precision that almost satisfies this requirement. Therefore, it is time to move into a rapid development phase in order to obtain a system ready for practical use by the year 2004. In this paper the status of individual technologies is discussed in light of this situation, and future requirements for developing a practical system are considered.

This paper reports the fabrication and evaluation of Mo/Al and Mo/Si multilayer films (MLs) for a wavelength of 18.5 nm. Calculated reflectivities of Mo/Al MLs at an incident angle of 10° were about 7% higher than those of Mo/Si MLs. MLs were fabricated using an RF-magnetron sputtering deposition system. The measured reflectivity of Mo/Al MLs was 33.5%. The cause of the decreasing reflectivity was supposed to be the surface and interfacial roughness. In the surface observation utilizing atomic force microscopy, the surface roughness of Mo/Al MLs was dominated by the Al layer. Therefore, the conditions for fabricating Al films were optimized.

We have designed and started the fabrication of 3-mirror ring-field projection optics for extreme ultraviolet lithography (EUVL) and an experimental exposure system using the projection optics, which enable a large-field (30 mm×20 mm), high-resolution (