GaN基材料的质量和LED光电性能的研究

发布时间：2018-06-25 19:45

本文选题：金属有机化学气相沉积 + 氮化　；参考：《太原理工大学》2015年硕士论文

【摘要】：氮化镓（GaN）半导体材料具有带隙宽、热导率高、化学性能稳定等优越性，已经广泛应用于高温功率器件、高频微波器件以及发光二极管（LED）等。目前，蓝光LED主要是在蓝宝石衬底上外延生长多层氮化镓基材料而制成的，而氮化镓基材料与蓝宝石之间存在较大的晶格失配，通过预先生长一层GaN缓冲层，才能提高在其上生长的GaN基材料晶体质量，，进而得到性能优异的器件。所以GaN缓冲层是整个发光材料生长的基础，是本文研究的重点；P型GaN基材料的掺杂直接决定LED器件性能，一直是蓝光LED外延生长中一个重要环节，也是本文的另一个研究内容。本文利用金属有机化学气相沉积（MOVPE）方法生长了氮化镓基半导体材料，并利用原子力显微镜（AFM），高分辨率X-射线衍射仪（HRXRD），霍尔测试仪（HALL）、原位生长监测曲线和芯片检测仪对薄膜材料及其制成的器件进行了表征。主要内容包括两个方面：1.蓝宝石衬底上的氮化，研究在低温下蓝宝石氮化时间对于氮化镓缓冲层和外延层的晶体质量的影响，得出低温下氮化时间对于GaN外延层晶体质量的影响规律，并提出了符合该规律的模型；2. AlGaN中的p型掺杂，研究掺杂源二茂镁（Cp2Mg）在AlGaN中的掺杂浓度对LED光电性质的影响，通过优化Cp2Mg流量，得到适当的空穴浓度，最终达到提高LED亮度的目的，同时揭示了p-AlGaN电子阻挡层的Mg掺杂浓度对LED的光电性能影响的原因。
[Abstract]:Gallium nitride (gan) semiconductor materials have been widely used in high-temperature power devices, high-frequency microwave devices and light-emitting diodes (LED) for their advantages such as wide band gap, high thermal conductivity and stable chemical properties. At present, sapphire LEDs are mainly grown on sapphire substrates by epitaxial growth of gallium nitride based materials. However, there is a large lattice mismatch between gallium nitride based materials and sapphire, and a layer of gan buffer layer is pre-grown. In order to improve the crystal quality of GaN-based materials grown on it, the devices with excellent performance can be obtained. Therefore, gan buffer layer is the basis of the growth of the whole luminescent material, and the doping of P type GaN-based material directly determines the performance of LED devices. It is always an important link in the epitaxial growth of blue LED. Also is another research content of this paper. Gallium nitride based semiconductor materials were grown by metal organic chemical vapor deposition (MOVPE). The thin films and their devices were characterized by atomic force microscope (AFM), high resolution X-ray diffraction (HRXRD), Hall tester (all), in situ growth monitoring curve and chip detector. The main content includes two aspects: 1. The effect of sapphire nitriding time on the crystal quality of gallium nitride buffer layer and epitaxial layer at low temperature was studied. The effect of nitriding time on the crystal quality of gan epitaxial layer was obtained. And the model is put forward which accords with the law. The p-type doping of AlGaN is studied. The influence of doping concentration of dopant source (CP _ 2mg) in AlGaN on the photoelectric properties of LED is studied. By optimizing the flow rate of Cp2mg, the appropriate hole concentration can be obtained, and finally the brightness of LED will be improved. At the same time, the influence of mg doping concentration in p-AlGaN electronic barrier layer on the photoelectric properties of LED is revealed.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8;O614.371

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