【作者】 陈恩光；

【导师】 衣立新； 王永生；

【作者基本信息】 北京交通大学 ， 光学， 2007， 硕士

【摘要】 超大规模集成技术的日益发展迫切需要研制硅基发光器件，以实现未来微型高速计算机芯片之间的光互联。晶体硅由于是间接带隙材料，其带间辐射复合效应非常低，难于达到发光器件的要求。因此，发光纳米硅（nc-Si）的研究便成为热点和前沿。含纳米硅薄膜材料由于其有对载流子纳米尺度的量子限域效应，可以与直接带隙发光材料相比拟的量子效应，所以引起研究者们的广泛关注。目前国内外研究最多的是纳米硅／硅的氧化物系统中的发光。但是两种材料的界面之间存在相当数量的悬挂键，影响纳米硅颗粒的发光性能，因此需要采用相应的手段来减少这种缺陷，进一步改善其发光性能。本文通过热蒸发方法在单晶硅衬底上沉积了SiO／SiO₂超晶格样品，在氮气保护下对样品进行高温退火，得到nc-Si／SiO₂超晶格结构。随后将该结构样品分别注入3.0×10¹⁴／cm²和3.0×10¹⁵／cm²两种剂量的H⁺。通过对样品的光致发光（PL）光谱的分析发现，H⁺注入后未经过二次退火的样品中，nc-Si的发光强度急剧下降；二次退火后的样品，随着退火温度的升高，nc-Si的发光强度逐渐增强；当注入足够剂量的H⁺时，其发光强度可以远远超过未注入时的发光强度。研究表明，nc-Si发光强度的变化取决于nc-Si表面缺陷面密度的改变，而nc-Si的表面缺陷面密度是由氢离子的注入剂量和注入后二次退火的温度等因素决定的。通过研究氢钝化对SiO₂中缺陷发光的影响发现，离子注入前后以及二次退火温度变化时，SiO₂中缺陷发光规律变得非常复杂，我们认为这可能是由于H⁺注入后SiO₂内部缺陷的分解和重新复合造成的，但是氢钝化对SiO₂内部缺陷发光的影响远不如对nc-Si发光的影响显著。更多还原

【Abstract】 There is an urgent requirement for an optical emiter that is compatible with standard silicon-based ultra-large-scale integration （ULSI） technology. Bulk silicon has an indirect energy bandage and is therefore highly inefficient as a light source, necessitating the use of other materials for this purpose. So the study on luminescent nanocrystalline Silicon has become the hot point and forehead at the field of agglomeration physics and microelectronics. The most attention has been paid to embedding Si nanocrystals film, mostly because of its high external quantum efficiency of light emission originated from quantum confinement of carriers in silicon crystals of nanometer size.SiO/SiO₂ superlattices samples were prepared on Si substrates by reactive evaporation of SiO powder in vacuum or an oxygen atmosphere. The samples were annealed in nitrogen atmosphere at high temperature subsequently. And then, these samples with formed Si nanocrystals were implanted with H⁺ to dose of 3.0×10¹⁴/cm² and 3.0×10¹⁵/cm² respectively at 20Kev. The PL spectra showed that the PL intensities of Si nanocrystals as-implanted dropped sharply compared with those without H⁺ implanting. The PL intensity increased gradually with the increasing re-annealing temperature; and it even could exceed that of Si nanocrystals without H⁺ implanting if the dose of H⁺ was enough. Our further investigations showed that the varieties of the PL intensities were mainly dependent on the area density of the defects on the surface of Si nanocrystals, and also the area density of the defects were influenced by the dose of H⁺ and further re-annealing temperatures.Basing on analysis of the effect of hydrogen passivation on photoluminescene of the defects in SiO₂, we found that photoluminescene of the defects in SiO2 was greatly ruleless with variety of re-annealing temperatures after ions implanting. It contributed by breakage and recombination on the defects within SiO₂ after H⁺ implanting and re-annealing, perhaps. However with increasing of the re-annealing temperature the PL intensities of nc-Si were more sensitive than those of the structure defects in the samples.更多还原