Ion projection lithography: Next generation technology?

Abstract

It is generally agreed that optical lithography is the method of choice for production of integrated circuits having minimum dimensions of down to 200 nm. By applying special enhancement techniques and complex resist processes the limit of optical lithography can be shifted down to about 150 nm in production using an exposure wavelength of 193 nm. However, this 193 nm equipment will be a one generation tool, so that new concepts are necessary for exposing structures smaller than 150 nm. The situation for this time (after about 2003) is still unclear. As lithography tools for after the year 2003 are not yet defined, there is an urgent need for preparative work for closing this technology gap. One of the most promising candidates for reaching 100 nm and below in production is ion projection lithography. In this article, the advantages and risks of this technique are compared to other possible candidates like x-ray, e-beam, and extreme ultraviolet. Insoluble production problems are identified. The feasibility of the relevant mask technologies, the availability of resist techniques are throughput and cost competitiveness are discussed.