Mix and match capability of e-beam direct-write for the 65-nm technology

An easy way to pattern 65nm CD target, when optical lithography technology is not available, is to use an Electron Beam Direct Write tool (EBDW), which is well known for its high resolution patterning potentials, with the drawback of a very low throughput. Emerging techniques of electron projection lithography also propose the same patterning capability with enhanced throughput. One of the most crucial issues, when dealing with integration, is the overlay capability of the systems. This paper exposes the studies made on the overlay capability issue of the LEICA EBDW installed in STMicroelectronics (STM) production plant in Crolles (France) and proves our tool is ready to support the 65nm node technology development.