氮化硅薄膜中硅纳米颗粒的形成机制研究

采用等离子体增强化学气相沉积技术,以SiH₄作为硅源, NH₃和N₂共同作为氮源,在单晶硅衬底上制备了不同的氮化硅薄膜. X射线衍射分析薄膜晶体结构,通过计算晶格尺寸大小证明了纳米硅颗粒的存在. 傅里叶变换红外光谱分析了薄膜中的键合作用的变化并结合化学反应过程对氮化硅薄膜中纳米硅颗粒的形成机制进行了研究,发现Si—Si键作为硅纳米颗粒的初始位置, 当反应朝着生成Si—Si的方向进行时,可以促进氮化硅薄膜中硅纳米颗粒的形成. X射线衍射分析和光致发光实验结果表明Si—Si键浓度增大时, 所形成的纳米硅颗粒的尺寸和浓度都随之增大.

The formation mechanism of the silicon nano-clusters embedded in silicon nitride

The silicon nitride films are prepared on c-Si substrates by plasma enhanced chemical deposition（PECVD） with silane as the silicon source in mixture gas（N₂/NH₃） as the nitrogen source.We prepare different kinds of films at different flow rates of the nitrogen with other conditions kept the same.X-ray diffraction（XRD） is employed to analyze the crystal structure,and the existence of the silicon nanoparticles embedded in the silicon nitride film is verified according to the caculation of the lattice size.Fourier transform infrared spectra are employed to probe the concentration evolutions of various chemical bonds with the flow rate of the nitrogen,with which by combining the chemical reaction process,the formation mechanism of the silicon nano-clusters embedded in silicon nitride is investigated.The results show the initial positions of silicon nanoparticles are conducible to the formation of silicon nanoparticles when the chemical reaction proceeds towards the direction in which the Si—Si bonds form.In addition,XRD analysis and photoluminescence characteristics show that the size and the concentration of the embedded nanoparticles increase with the flow rate of the nitrogen increasing.