[1] Natl Cheng Kung Univ, Inst Microelect, Tainan 70101, Taiwan
[2] Natl Cheng Kung Univ, Dept Elect Engn, Tainan 70101, Taiwan
[3] S Epitaxy Corp, Hsin Shi 744, Taiwan
[4] Natl Yunlin Univ Sci & Technol, Dept Elect Engn, Touliu, Yunlin, Taiwan
[5] Na Jeon Jr Coll Technol & Commerce, Dept Elect Engn, Yenshui 737, Taiwan
[6] Chin Min Coll, Dept Elect Engn, To Fen 351, Taiwan