gan基紫外led外延p型结构与工艺分析-analysis on epitaxial p - type structure and process of gan - based ultraviolet led.docx

摘要近年来，随着 UVLED 技术的进一步发展，其以广泛的应用优势涉及到了生 活的各个领域，特别是在半导体照明领域，对于提高紫外 LED 的光效和亮度的研 究仍然很重要，本文介绍了提高 LED 内外量子效率的一些有效手段，最后就 P 型 层对于 LED 发光效率的影响进行了详细的研究。通过表征手段 X 射线衍射、光 致荧光谱分析了不同生长参数下外延片的质量及光致发光波长等方面的差异，对 于经过常规 LED 正装工艺制成的芯片，采用 EL 表征了器件的发光特性。本文具体对于紫外 LED 的 P 型结构的研究，是通过 P 型 AlGaN 电子阻挡层 的厚度及 Al 组分的优化，在 Al 组分为 0.2，厚度达到 12.5nm 左右的时候，认为 电子阻挡层不仅抑制了量子阱中位错的延伸，使得外延片的质量提高，而且还有 效的抑制了电流的溢出，达到了提高光效的目的，对于 P 型 GaN 层的优化，采取 TMGa 流量、CP2Mg 流量的改变来优化其厚度和生长速率，在 TMGa 流量为 30sccm，CP2Mg 流量为 170sccm 时，进一步提高了 LED 的亮度。关键词：UVLED P 型 AlGaNP 型 GaNABSTRACTRecent years, the UVLED technology is adopted in all areas of life as its further development, especially in semiconductor lighting field, the research for improving the efficiency and brightness of UV-LED remains very important. Some effective measures to enhance the internal and external quantum efficiency are presented in this work, and detail researches about the effect of P-type layer on LED luminous efficiency are made. Characterization methods such as XRD and photoluminescence spectrum are used to analyze the variances of the quality of epitaxy chips and photoluminescence wavelengths under different growth parameters, for the chips made by conventional LED process, we use EL to characterize the luminescence properties.In this work, our research on ultraviolet LED P-type structure is specified by optimizing the thickness of P-AlGaN electron blocking layer and the constituent of Al. When the constituent content of Al is 0.2 and the thickness is up to 12.5nm, it is expected that electron blocking layer can restrain the extension of dislocation in quantum well thus improve the quality of epitaxy chips, it can also suppress the current overflow to improve the luminous efficiency. For the purpose of P-GaN layer optimization, we can change the thickness and growth rate of the layer by modifying the flow of TMGa and CP2Mg. When the TMGa flow is 30sccm and CP2Mg flow is 170sccm, we can further improve the LED luminance.Key words: UVLEDP-AlGaN P-GaN目录第一章 绪论