周期性梯度富硅SiNx薄膜的微结构与发光特性

doi:10.15541/jim20140123

摘要/Abstract

摘要：

采用磁控共溅射结合快速光热退火技术在单晶硅和石英衬底上制备了含硅量子点的周期性梯度富硅SiN_x薄膜(梯度薄膜)和单层富硅SiN_x薄膜(单层薄膜)。采用Raman光谱、掠入射X射线衍射(GIXRD)、透射电子显微镜(TEM)、傅里叶变换红外(FTIR)光谱和光致发光(PL)光谱分析了薄膜的结构特性、键合特性和发光特性。Raman光谱、GIXRD和TEM结果表明, 梯度薄膜和单层薄膜中的硅量子点晶化率分别为41.7%和39.2%; 梯度薄膜的硅量子点密度是单层薄膜的5.4倍。FTIR光谱结果显示两种薄膜均为富硅氮化硅薄膜, 梯度薄膜的硅含量小于单层薄膜。PL光谱结果表明梯度薄膜中的辐射复合缺陷少于单层薄膜。

关键词: Si量子点, 氮化硅薄膜, 快速光热退火, 光致发光

Abstract:

Periodic gradient Si-rich SiN_x (G-SRSN) thin films and single-layer Si-rich SiN_x (S-SRSN) thin films were deposited on monocrystalline silicon wafers and quartz substrates by combination of magnetron co-sputtering and rapid photo-thermal annealing. Raman spectroscope, grazing incident X-ray diffraction (GIXRD), transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscope and photoluminescence (PL) were used to analyze the structure, bonding configurations and luminescence of the films. Raman, GIXRD and TEM results show that the crystalline fractions of G-SRSN and S-SRSN thin films are 41.7% and 39.2%, respectively. Quantum dots density of G-SRSN thin film is 4.4 times higher than that of S-SRSN thin film. The FTIR spectra demonstrate that both G-SRSN and S-SRSN films are Si-rich SiN_x, but Si content of the former is lower than that of the later. PL spectra suggest that the G-SRSN thin films possess a lower radiative recombination defect density than the G-SRSN thin films.

Key words: silicon quantum dots, silicon nitride film, rapid photo-thermal annealing, photoluminescence

中图分类号:

O484

陈小波, 杨雯, 段良飞, 张力元, 杨培志. 周期性梯度富硅SiN_x薄膜的微结构与发光特性[J]. 无机材料学报, 2014, 29(12): 1270-1274.

CHEN Xiao-Bo, YANG Wen, DUAN Liang-Fei, ZHANG Li-Yuan, YANG Pei-Zhi. Microstructure and Luminous Property of Periodical Gradient Si-rich SiN_x Thin Films[J]. Journal of Inorganic Materials, 2014, 29(12): 1270-1274.

图/表 9

图 1 制备薄膜时溅射的功率变化

Fig. 1 Variation of the sputtering powers during film Sample 1, Single layer film; Sample 2, gradient- layer film

图 2 梯度薄膜的结构示意图

Fig. 2 Schematic diagram of the gradient-layer film structures

图 3 单层薄膜(样品1)和梯度薄膜(样品2)的拉曼光谱图

Fig. 3 Raman spectra of single-layer film (Sample 1) and gradient-layer film (Sample 2)

表 1 单层薄膜和梯度薄膜样品的拉曼光谱的曲线拟合结果

Table 1 Curve-fitting results from Raman spectra of single-layer film and gradient-layer film

Sample	TO mode of nc-Si phase	Si crystal volume fraction, X_c
	Peak positon/cm^-1	Integrated Intensity, I_c/(a.u.)	Average size/nm
1	516.4	2146.4	2.7	39.2%
2	516.4	4349.4	2.7	41.7%

图 4 单层薄膜(样品1)和梯度薄膜(样品2)的GIXRD结果

Fig. 4 GIXRD results for single-layer film (Sample 1) and gradient-layer film (Sample 2)

图 5 单层薄膜(a)和梯度薄膜(b)的横截面TEM照片(硅量子点的晶体结构用红色圆圈标注)

Fig. 5 Cross-sectional TEM images of single-layer film (a) and gradient-layer film (b). The crystalline structure of Si qu-an-tum dots is circled by red circles

图 6 单层薄膜(样品1)和梯度薄膜(样品2)的FTIR结果

Fig. 6 FTIR results for single-layer film (Sample 1) and gradient-layer film (Sample 2)

图 7 单层薄膜和梯度薄膜在室温下的PL谱

Fig. 7 PL spectra of single-layer film (Sample 1) and gradient-layer film (Sample 2) under room-temperature

表 2 单层薄膜和梯度薄膜样品的PL谱的各峰积分强度

Table 2 Integrated intensity from PL spectra of sing-l-e-layer film and gradient-layer film

Sample	Integrated intensity/(a.u.)
Sample	P1	P2	P3
Single-layer film	13.4	15.5	2.2
Gradient-layer film	14.1	12.1	1.4

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