Sub‐half‐micron metal–oxide–semiconductor device fabrication using a compact synchrotron radiation lithography system

In order to evaluate the usefulness of the compact synchrotron radiation (SR) lithography system using a superconducting synchrotron light source ‘‘AURORA,’’ sub‐half‐micron metal–oxide–semiconductor devices were fabricated. This article describes the SR lithography system including x‐ray masks, the device fabrication processes, and the characteristics of the resulting devices. Excellent overlay accuracy, better than 90 nm (3 σ), was obtained using chromatic bifocus alignment optics in most levels. Though no radiation effect is observed in initial device characteristics, hot‐electron‐induced instability is observed in 2000 mJ/cm²‐irradiated devices. If high‐speed resists with 100–200 mJ/cm² sensitivity were used, the instability would be reduced to a negligible level.