1. Micro Device & Machinery Solution Division, Samsung Techwin R&D Center, Seongnam-si, Gyeonggi-do, 463-400, Republic of Korea
2. School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
3. Graphene Square Inc., Inter-University Semiconductor Research Center, Seoul 151-747, Republic of Korea