Microstructure and Luminous Property of Periodical Gradient Si-rich SiNx Thin Films

doi:10.15541/jim20140123

Abstract

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

CLC Number:

O484

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.

Figures/Tables 9

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

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

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

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%

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

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

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

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

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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