[1] Samsung Adv Inst Technol, Nano Devices Lab, Suwon 440600, South Korea
[2] Konkuk Univ, Dept Phys, Seoul 143701, South Korea
[3] Samsung Elect Co Ltd, Semicond R&D Ctr, Proc Dev Team, Suwon 440600, South Korea
[4] Inha Tech Coll, Dept Syst & Comp Engn, Inchon 402753, South Korea