Bonding configurations and optical band gap for nitrogenated amorphous silicon carbide films prepared by pulsed laser ablation
Bonding configurations and optical band gap for nitrogenated amorphous silicon carbide films prepared by pulsed laser ablation
复制标题
脉冲激光烧蚀氮化非晶碳化硅薄膜的键合结构和光学带隙
DOI：
10.1063/1.1498885
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发表时间：
2002
影响因子：
3.2
通讯作者：
F. Neri
中科院分区：
文献类型：
--
作者：
S. Trusso;F. Barreca;F. Neri
在可控的氮气气氛中烧蚀烧结碳化硅靶沉积了SiCxNy薄膜。用X射线光电子能谱（XPS）和椭圆偏振光谱仪研究了薄膜的结构和光学性质。发现氮含量取决于氮分压并且不超过7.5%。XPS测量的N 1 s，C 1 s，和Si 2 p光电子峰指出，氮优先键合到硅原子的Si-C和Si-Si键密度的同时减少。还观察到sp3杂化碳键的轻微增加。光学带隙Eg值，从拟合椭圆偏振数据与适当的多层模型，被发现增加到2.4 eV的值为1.6 eV的非氮化样品开始。这一发现与较弱的Si-Si键逐渐被较强的Si-C键和Si-N键取代有关，这可能涉及电子的去除。
SiCxNy thin films have been deposited by ablating a sintered silicon carbide target in a controlled nitrogen atmosphere. The structural and the optical properties of the films were investigated by x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry. The nitrogen content was found to be dependent on the nitrogen partial pressure and did not exceed 7.5%. XPS measurements of the N 1s, C 1s, and Si 2p photoelectron peaks pointed out the nitrogen preferential bonding to silicon atoms with a concurrent decrease of the Si–C and Si–Si bond density. A slight increase of sp3 hybridized carbon bonds has been also observed. The optical band gap Eg values, obtained from fitting the ellipsometric data with an appropriate multiple layers model, were found to increase up to 2.4 eV starting from a value of 1.6 eV for a non-nitrogenated sample. This finding was related to progressive substitution of the weaker Si–Si bonds by the stronger Si–C and Si–N ones which, presumably, involves the removal of electr...