Applied Science and Convergence Technology 1992; 1(1): 43-49
Published online February 1, 1992
Copyright © The Korean Vacuum Society.
Kyung-Won Lee,Ki-Seok An,Kun-A Kang,Chong-Yun Park,Soon-Bo Lee
RHEED apparatus which is one of the systems of surface structure analysis has been constructed. Electron beam is focused by means of magnetic lens, and the beam divergence is about 1×11^(-3) rad. The Acceleration voltage of this RHEED apparatus is continuously variable from 0 to 20㎸. K and Cs-adsorbed structures on Si(111)7×7 surface at room and high temperatures(200×700℃) have been investigated by RHEED. It is observed that the K and Cs-adsorbed Si(111)surface structures at saturation coverage are Si(111)7×7-K and Si(111)l×1-Cs at room temperature, respectively. When the specimen temperature was elevated during evaporation, the 3×1 structure appears in the range of temperature between 300℃ and 550℃, and the 1×1 structure appears above 550℃ in K/Si(111) system. Also, in Cs/Si(111) system the √3×√3structure appears at 300℃, and the √3×√3+3×1 structure appears between 350℃ and 400℃.