快速热退火增强非晶SiC_xO_y薄膜蓝绿光发射特性研究

Effects of rapid thermal annealing on the enhanced blue-green photoluminescence from amorphous Silicon oxycarbide films

采用甚高频等离子增强化学气相沉积技术,以SiH_4,CH_4和O_2作为反应气源,在150℃下制备非晶碳氧化硅薄膜,并对薄膜进行不同条件下快速热退火处理,研究快速热退火处理对其结构和发光特性的影响.实验表明,原始沉积薄膜在可见光全波段展现较强的光致发光特性,经过快速热退火处理后,其发光强度显著增强.薄膜在700℃经过快速热退火10s后,相比于原始沉积薄膜,其发光强度增强6倍,肉眼可见强的蓝绿光光发射.光荧光谱(PL)分析表明,薄膜的发光峰位不随激发波长的改变而发生明显变化.通过结合拉曼(Raman)光谱及傅里叶红外吸收(FTIR)光谱对薄膜的微结构及键合结构分析,分析了不同退火温度和退火时间对其蓝绿光发射增强机制的影响.

Luminescent amorphous Silicon oxycarbide （a-SiCxOy）films were fabricated in high frequency plasmaenhanced chemical vapor deposition（VHF-PECVD）system at a low temperature of 150 ℃ by using the gas mixture of Sill4 ,CH4 and O2 as precursor. The post-treatment of rapid thermal annealing was performed on the a-SiCxOy films under different thermal annealing temperatures for different thermal annealing times. The effect of rapid thermal annealing on the microstructure and photoluminescence （PL）characteristics of a-SiCxOy films was investigated. It is found that rapid thermal annealing results in a remarkable enhancement in the blue-green PL, which can be clearly observed with naked eyes in a bright room. Rapid thermal annealing of the films at 700℃ for 10 s was found to significantly enhance the integrated PL intensity IeL Of the blue-green PL by more than six times when compared with the as-deposited film. The PL spectra show that the PL peak position of each film is independent of the excitation wavelength. The structure and the chemical compositions of the films were further investigated by Raman spectroscopy and Fourier transform infrared absorption（FTIR）spectroscopy, respectively. Based on the PL results and the analyses of microstructure and bonding configurations of the films, the effects of thermal annealing temperature and thermal annealing time on the enhanced blue-green PL were investigated.