Wu Yang, Yi Li-xin, Wang Shen-wei, Du Yu-fan, Huang Sheng, Ji Guo-rui, Wang Yong-sheng
Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 May;29(5):1260-3.
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--Si(4-y) (0 < or = y < or = 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, Si3N4 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 Si3N4).
采用磁控溅射技术在p型Si(100)衬底上沉积非晶SiNx薄膜。然后用布鲁克Tensor 27傅里叶变换光谱仪对样品进行检测。通过傅里叶变换红外(FTIR)光谱检测到SiNx薄膜的一个强吸收带(812至892 cm(-1))，该吸收带归属于Si-N-Si键的伸缩振动模式。显然，FTIR光谱显示随着溅射功率的增加，吸收峰发生红移；然而，退火后随着温度升高吸收峰发生蓝移。本文根据随机键合模型(RBM)和中心力模型(CFM)研究了SiNx薄膜的沉积过程和内部结构。随着N(Si)与N(N)比例的增加，Si-N-Si的角度发生变化并相应形成不同结构。因此建立了Si-Ny-Si(4-y)(0≤y≤4)模型来解释SiNx薄膜的内部结构。研究表明，随着溅射功率的增加，SiNx薄膜中相应形成了Si-N4四面体、Si-N-Si3、Si-N2-Si2、Si-N3-Si和Si-Si模式。在沉积过程中总共形成了五种模式。Si-N-Si键的不同伸缩振动模式对应于不同溅射功率制备的薄膜的不同内部结构。随着温度升高，原子活性增加，这会使Si-N-Si的角度趋于一致。结果，在较高温度的退火过程中，SiNx薄膜发生相分离形成Si3N4和Si纳米晶体，这将导致吸收峰蓝移至870 cm(-1)(Si3N4的标准吸收峰)。
