磁控溅射法沉积SiNx非晶薄膜的生长机制及结构分析  

Deposition and Structures Analysis of Amorphous SiN_x Films Prepared by Magnetron Sputtering

作　　者：邬洋[1] 衣立新[1] 王申伟[1] 杜玙璠[1] 黄圣[1] 冀国蕊[1] 王永生[1] 

机构地区：[1]北京交通大学光电子技术研究所,发光与光信息技术教育部重点实验室,北京100044

出　　处：《光谱学与光谱分析》2009年第5期1260-1263,共4页Spectroscopy and Spectral Analysis

基　　金：国家“973”计划项目(2003CB314707);国家自然科学基金项目(60577022,10434030);教育部留学回国人员基金项目(2005383);北京交通大学科技基金项目(2004SM049)资助

摘　　要：利用磁控溅射技术在单晶Si衬底上沉积了SiNx非晶薄膜。样品的傅里叶变换红外吸收光谱(FTIR)显示,SiNx非晶薄膜在812～892cm-1范围内存在一个较强的吸收谱带。该吸收谱带对应于Si—N—Si键的伸缩振动吸收(Stretching vibration mode),其吸收峰峰位随着溅射功率的增大明显红移;但退火后,该吸收峰又逐渐蓝移。结合中心力模型和自由结合模型,分析了磁控溅射过程中SiNx非晶薄膜的生长机制和内部结构。研究认为,随着溅射功率的提高,薄膜中先后形成Si-N4四面体,Si—N—Si3,Si-N2-Si2及Si-N3-Si等结构,这几种结构分别对应着Si—N—Si键的不同模式的振动吸收。随着退火温度的升高,分子热运动逐渐加剧,非晶SiNx薄膜发生相分离,生成Si3N4和Si纳米晶颗粒,因此,Si—N—Si键的吸收峰逐渐向Si3N4的特征振动吸收峰位870cm-1靠近。Amorphous SiNx films were deposited on p-type Si（100）substrates by magnetron sputtering technology. The samples were then detected by a Bruker Tennsor 27 Fourier transform spectrometer. One intense absorption band of the SiNx films （from 812 to 892 cm^-1 ）which was assigned to the stretching vibration mode of Si-N-Si bond was detected by Fourier transform infrared （FTIR）spectroscopy. Obviously, it was showed that a red shift of the absorption peak occurred in the FTIR spectrum with the sputtering power increasing; nevertheless, a blue shift of the absorption peak occurred after annealing with the temperature increasing. In the present paper, the deposition process and inner structures of the SiNx films were studied according to RBM （random bonding model）and CFM （central force model）. With the increase in the ratio of N（Si）to N（N）, the angle of the Si-N-Si changed and the different structures were formed correspondingly. Therefore the Si-Ny-Si4-y （0≤y≤4）models were set up to explain the inner structure of the SiNx films. The investigation showed that Si-N4 tetrahedron, Si-N-Si3, Si-N2-Si2, Si-N3-Si and Si-Si modes were formed accordingly in the SiNx films with the sputtering power increasing. And five models in total were formed during the deposition process. Different stretching vibration modes of Si-N-Si bond were corresponding to the different inner structures of thin films prepared by different sputtering power. With the temperature increasing, the activity of atoms increased which would let the angle of the Si-N-Si go to identical. As a result, Si3 N4 and Si nanocrystals were formed with the phase separation of SiNx films during the annealing process with higher temperature, which would result in a blue shift to 870 cm^-1 （the standard absorption peak of Si3 N4 ）.

关 键 词：SiN_x非晶薄膜 磁控溅射 傅里叶变换红外光谱 

分 类 号：O472.3[理学—半导体物理]