By Stefan Wurm, SEMATECH, Austin, Texas
Extreme ultraviolet (EUV) technology maturity must be demonstrated by the performance of the first EUV lithography (EUVL) alpha tools, by the readiness of EUVL infrastructure to support beta-level EUVL lithographic performance in the near future, and by the overall cost of ownership (CoO) of EUVL. While EUVL technology and infrastructure development have made excellent progress over the past several years, meeting the production requirements for EUVL source, mask, optics, and resist is very challenging. This article reviews the current status and outlook for inserting EUVL into semiconductor manufacturing.
EUVL is one of the main contenders for high-volume manufacturing (HVM) lithography at the 32nm half-pitch (hp) node . Like other next generation lithography (NGL) technologies, EUVL was originally projected for much earlier insertion into manufacturing, i.e., initially for the 90nm hp node, then for the 65nm hp node, and recently, for the 45nm hp node.
First, the introduction of EUVL was pushed out because the industry was so successful in extending sub-wavelength imaging with 193nm dry lithography using sophisticated optical proximity correction (OPC) methods while tool suppliers continued to increase numerical aperture (NA) and perfected techniques like focus drilling. When immersion techniques that had long been used in microscopy were enthusiastically embraced by lithography engineers, the introduction of EUVL was pushed out even further. Although some issues remain