Formation of an Ultra-thin KCl Layer on the Silicon Surface

• Main Author: 吳俊緯
• Other Authors: Deng-Sung Lin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/d6s69d

碩士 === 國立交通大學 === 物理研究所 === 92 === The thesis describes the growth of potassium chloride(KCl), and its thermal reactions on the Ge/Si(100)-2�e1 surface. Synchrotron radiation was used to excite the Ge 3d、K 3p、Cl 2p photoemission electrons. When Cl2 was exposed onto the Ge/Si(100)-2�e1 surface, Cl2 molecules dissociate and chemisorb on surface, and form both Cl-Si and Cl-Ge bonds. The KCl films were obtained by evaporating potassium on the Cl-terminated Ge/Si(100) surface at room temperature. The Cl-Si and Cl-Ge bonds disappears after potassium adsorption. The valence bands spectra indicates that Cl and K become KCl ionic solid on the Ge/Si(100) surface. Annealing the samples to temperature above 325K, KCl desorbs from the Ge/Si(100) surface. At 665K, the KCl thin layer is gone. Small amount of potassium tends to diffuse into the subsurface. Additionally, we studied the thermal reactions of HCl on the Si(100)-2x1 surface. Some Si-Si dimer was broken by chlorine at 605K, so that a part of Si-Cl bonds were replaced by Cl-Si-Cl bonds. Above 915K, Cl gradually desorbs from the Si(100)-2x1 surface via SiCl2 desorption.