Process and Metrology Challenges for Nano-scale Electronics

The design and fabrication of nano-scale materials and devices opens a new range of challenges for measurements and processing. At scales on the order of a few nano-meters, the electronic, thermal and optical properties of familiar materials, such as Silicon, are profoundly altered by the onset of quantum confined conditions. The promises of the use of 2 and 1D materials such as MoS2 and Carbon nano-tubes are constrained by the need to develop industrial level processing methods capable of large-scale and economically favorable fabrication of useful devices and systems. For materials on nm-scales, fundamental limitations related to the onset of atomic-level damage creation in surfaces, interfaces and device volumes limit the available ion and photon energies for fabrication processes. For example, in ion beam processing, the use of ions at kinetic energies of 100 eV or less lead to process mechanisms that mix the usual concepts of implantation, deposition and chemical reaction (etching). Control of process beams for nm-scale structures call for design of new process tools that operate efficiently in this energy regime and at a much higher level of control of such factors and particle energy spread and incident angle controls. Overlying all of these issues is the need to advance the state of the art for process characterization metrologies to provide accurate and efficiently obtainable atomic scale information of the characteristics of individual processes and nano-scale device structures.