Si／SiNx／SiO2多层膜的光致发光  

Photoluminescence of Si/SiN_x/SiO_2 Multilayers

作　　者：陈青云[1] 段满益[1] 周海平[1] 董成军[1] 魏屹[1] 纪红萱[1] 黄劲松[1] 陈卫东[1] 徐明[1] 

机构地区：[1]四川师范大学物理与电子工程学院固体物理研究所低维结构物理实验室,四川成都610068

出　　处：《发光学报》2008年第2期363-370,共8页Chinese Journal of Luminescence

基　　金：四川省青年科技基金(08JJ0025);教育部留学回国人员科研启动基金(教外司留[2007]1108);四川师范大学学生科研创新基金资助项目

摘　　要：采用射频磁控溅射法,制备了具有强光致可见发光的纳米Si/SiNx/SiO2多层膜,利用傅立叶红外吸收(FTIR)谱,光致发光(PL)谱对其进行了研究。用260nm光激发得到的PL谱中观察到高强度的392nm(3.2eV)和670nm(1.9eV)光致发光峰,分析认为它们分别来自于缺陷态≡Si-到价带顶和从导带底到缺陷态≡Si-的辐射跃迁而产生的光致激发辐射复合发光。PL谱中只有370nm(3.4eV)处发光峰的峰位会受退火温度的影响,结合FTIR谱认为370nm发光与低价氧化物—SiOx(x<2.0)结合体有密不可分的关系。当SiO2层的厚度增大时,发光强度有所增强,800℃退火后出现最强发光,认为具有较大SiO2层厚度的Si/SiNx/SiO2结构多层膜更有利于退火后形成Si—N网络,能够得到更高效的光致发光。用量子限制-发光中心(QCLC)模型解释了可能的发光机制,并建立了发光的能隙态(EGS)模型。Si/SiNx/SiO2 muhilayers are prepared on Si（100） at room temperature by radio-frequency （RF） magnetron sputtering. The optical properties of these films have been investigated using Fourier Transform Infrared （FTIR） absorption and photoluminescence （PL） spectra, the origins of emission bands in PL spectra are discussed in detail. Strong photoluminescence at 392 nm （3.2 eV ） and 670 nm （ 1.9 eV ） is observed, which are caused by the electronic transitions of ≡ Si^ - → Ev（the valence band top） and Ec （ the conduction band bottom）→ ≡ Si^ -. It is found that the stretching vibration in FTIR spectra shifts toward to the lower wave numbers at a high peak of the Si-O bonds around 1 056 cm^- 1 annealing temperature. Accordingly, the PL peak at 370 nm depends upon the annealing temperature, it was suggested that the peak appeared at 370 nm can be related to the -SiOx （x 〈 2.0） defect states level. The Si/SiNx/SiO2 multilayers are Si-rich, in which Si-N bonds are broken under high temperature environment, then the Si-N bonds will form again in the Sirich environment. When the thickness of SiO2 increases, the PL intensity of Si/SiNx/SiO2 muhilayers increases. After annealing at 800 ℃, the strongest PL intensity appears. It was suggested that the bigger thickness of SiO2 in Si/SiNx/SiO2 muhilayers, the more beneficial of forming Si-N net in film, and the more effectively PL. The strong PL is relevant with the content of silicon dangling bond ≡ Si, nitride dangling bond ≡N, and oxygen-related defects. The quantum confinement-luminescence center （QCLC） model was adopted to interpret the PL results. The gap state model was built in order to explain the PL phenomenon.

关 键 词：Si/SiNx/SiO2多层膜 红外吸收 光致发光 

分 类 号：O482.31[理学—固体物理]