1. Division of Industrial Metrology Korea Research Institute of Standards and Science Daejeon 305‐340 Korea
2. Manufacturing Technology Center SK Hynix Inc. Icheon 467‐701 Korea
3. Major of Nano Science University of Science and Technology Daejeon 305‐340 Korea
4. Department of Chemistry Hanyang University Seoul 133‐791 Korea
5. Division of Electrical and Biomedical Engineering Hanyang University Seoul 133‐791 Korea