1. National Center for Nanoscience and Technology, Beijing 100190, China
2. National
Key Laboratory of Science and Technology on Micro/Nano Fabrication,
Institute of Microelectronics, Peking University, Beijing 100871, China
3. Department
of Microelectronics, Delft University of Technology, Delft 2628CT, The Netherlands
4. Institute
of Molecular Medicine, Peking University, Beijing 100871, China