A study on fabrication, microstructure and photoluminescence properties of SRN and metal doped SRN thin films

• Main Authors: Cheng-HanLi, 李承漢
• Other Authors: Chen-Kuei Chung
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/37937147699334748330

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 101 === In this study, silicon-rich nitride (SRN) thin films were deposited on the Si(100) substrates and anodic aluminum oxide (AAO) templates by radio frequency reactive magnetron sputtering. We investigated different annealing process, annealing temperature and metal doping affects the SRN nanocomposites thin films. The material properties include microstructure, surface morphology and photoluminescence behaviors of the SRN and metal doped SRN films. We used grazing incidence X-ray diffraction (GIXRD) to analyze crystal phase, high-resolution field emission scanning electron microscope (HR-SEM) to analyze surface morphology, Raman spectroscopy, X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) to analyze the chemical compositions and bonding, photoluminescence (PL) to measure band gap of the SRN and metal doped SRN films. Then we used these results to explain our experimental data. In the first part, the microstructure and photoluminescence property of SRN thin films as function of different annealing process were discussed. The CO2 laser annealing was better than high vacuum annealing to increase crystalline and bonding intensity, because the CO2 laser energy generate higher energy will help to precipitate silicon nanocrystals. Due to the nc-Si, defect states in imperfection of interface between the Si-O-Si and the located state related to the Si-N bond in the SiNx matrix to produce the visible PL and increasing temperature enhances the formation of more recombination in the localized states of Si-N bonds and nc-Si for the improved PL intensity. In the second part, the microstructure and optoelectronic characteristics of metal (Al, Ti, Ta) doped SRN nanocomposite films were discussed. High temperature annealing in the air will increase the oxygen content of the films and will form the metal oxide. Compared to single layer SRN film, this metal oxides produced the deep-level emissions of oxygen vacancies and lattice emissions will help metal doped SRN nanocomposite films as a whole to enhance the luminous intensity and wavelength. Therefore, the nanocomposite films with novel metal doped PL should apply to the optoelectronic devices. In the final part, the effect of different size AAO porous on the evolution of microstructure and PL behavior by nc-Si on AAO template, due to the spatially confined synthesis of AAO template that the size of nc-Si could be controlled by the pore diameter of AAO template. Quantum size effect was obvious for the present samples and remarkable red shift was shown in the obtained spectra.