Application of X rays to nanolithography

The development of a successful fabrication process for electron devices with dimensions in the sub-100-nm domain will require a form of a high-resolution and high-volume patterning. In this paper we discuss the extensibility of X-ray lithography to this domain in terms of the resolution of the technique, considering in detail the effect of diffraction and photoelectrons. We show that optimized masks and exposure systems can deliver with relative ease patterning in the 70-50-nm region, while phase-shifting techniques can extend the resolution to sub-40 nm. High volume is provided by the use of the mask. The challenge remains in the fabrication of the 1X mask, and in the achievement of the necessary placement accuracy.