Mar 19, 2009
LIL fabricates high-resolution nanostructures fast
High-intensity laser interference lithography (LIL) offers a simple and cost-effective method to prepare large-area periodic surface patterns well below 5 nm in size without resist and without elaborate processing.
Industrial end users are currently discouraged from expanding their nanotechnology-related business activities by either unacceptably high costs or difficulties in controlling production processes on a nanometric scale. The main lithography technologies available for direct structuring of nano features include ion beam lithography, electron beam lithography and scanning probe lithography. All of them use a time-consuming sequential writing strategy, which requires high mechanical and electrical stability of the system.
Looking ahead, researchers believe that LIL will play a key role in unlocking the full potential of nanolithography. The main advantages of the nanostructuring technique are high resolution compared with other optical technologies, and low cost and high efficiency compared with other beam technologies. LIL is well suited to industrial use and could help to drive the rapid development of nanoscience leading to new processes and applications.
In recent work, which was published in Nanotechnology, researchers have achieved ordered nano-patterns with feature sizes less than 5 nm on semiconductor materials. Four-beam interference patterns were generated to create periodic arrays of holes in GaAs, covered with SiO2 bubbles, which were then written directly into the sample. The smallest feature could not be observed by atomic force microscopy (AFM) with resolution better than 5 nm, which indicates that the smallest feature of the pattern was less than 5 nm. The time taken to fabricate the LIL nano-patterns was less than 5 min including processing.
This work was financed by the European FP6 Project "Development of lithography technology for nanoscale structuring of materials using laser beam interference (DELILA)" (contract 027976).
About the author
The work was performed within the consortium of the EU FP6 project DELILA. Senior researcher Dr Changsi Peng, assistant researchers Chunlei Tan and Janne Pakarinen, and Prof. Markus Pessa are working for the Optoelectronics Research Centre (ORC), Tampere University of Technology, Tampere, Finland. Researchers Vladgmir N Petryakov and Dr Yury K Verevkin are working for the Institute of Applied Physics (IAP), Russian Academy of Sciences, Nizhny Novgorod, Russia. Dr Jin Zhang and Dr Zuobin Wang are working for the Manufacturing Engineering Centre (MEC), Cardiff University, Cardiff, UK. Dr Sandiago M Olaizola is working for the Department of Microelectronics, Centro de Estudios e Investigaciones Técnicas de Gipuzkoa (CEIT), San Sebastian, Spain. Dr Thierry Berthou is working for SILIOS Technologies SA (SILIOS), Peynier, France. ORC is mainly responsible for materials research, IAP and CEIT are mainly responsible for LIL systems, MEC is the coordinator of DELILA, SILIOS is mainly responsible for the exploitation of the LIL technology. For more information, contact Dr Changsi Peng.