JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 35, page. S1063 - S1066, 1999-12
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, vol. 17, no. 2, page. 497 - 499, 1999-03
SOLID-STATE ELECTRONICS, vol. 43, no. 2, page. 435 - 438, 1999-02