1. Mechatronics R&D Center, Samsung Electronics Co., Ltd 1 . 1-1, Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, South Korea
2. School of Integrative Engineering, Chung-Ang University 2 , Seoul 156-756, South Korea
3. Etch Process Development Team, Applied Materials Korea 3 , 6th FL, Lucestar Biz Bldg., 594-7, Dongtangiheung-ro, Hwaseong-si, Gyeonggi-do 18469, South Korea