SBIR Phase I: Hybrid Precursor HVPE Growth of AlGaN

这个小企业创新研究第一阶段项目建议开发一种新的外延生长工艺，用于生产基于iii -氮化物材料的持久（寿命20,000小时），高效率（插拔效率10%）的深紫外发光二极管（DUV led）。由于缺乏原生衬底，DUV led是由生长在蓝宝石衬底上的异质外延AlInGaN或AlGaN薄膜制成的，并且受到高密度晶体缺陷的影响。生长缺陷的大量集中降低了DUV led的效率、可靠性和寿命。以往的经验表明，由于缺陷湮灭和应变松弛，在厚膜中可以减少晶体缺陷。该研究的目标是开发一种新工艺，以促进厚iii -氮化物材料的生长，从而允许材料松弛和缺陷湮灭。与金属有机前驱体相比，使用不发生强烈气相反应的稳定前驱体可以实现高生长速率。PI还建议修改混合前驱体气相外延（HPVPE）淋浴喷头和气体输送系统，该系统已与金属有机气体一起使用。将对所生长的材料和所构建的led进行表征和评估，以优化所提出的工艺。该建议的技术前景是有希望的，因为厚层的增长预计会导致位错的消除。拟议的活动将促进对高质量材料和器件生长的认识和理解，这些材料和器件通常很难生长。这方面的工作有望使led以外的技术受益。

This Small Business Innovation Research Phase I Project proposes to develop a new epitaxial growth process for production of long-lasting (lifetime 20,000 hours), high-efficiency (wall-plug efficiency 10%) deep ultraviolet light emitting diodes (DUV LEDs) based on III-Nitride materials. Due to the lack of native substrates DUV LEDs are made from heteroepitaxial AlInGaN or AlGaN films grown on sapphire substrates and suffer from a high density of crystal defects. Large concentration of growth defects reduces DUV LEDs' efficiency, reliability and lifetime. Previous experience reveals that crystal defects can be reduced in thick films due to defects annihilation and strain-relaxation. The goal of the research is the development of a new process to facilitate the growth of thick III-Nitride materials and as a consequence allow for material relaxation and defects annihilation. The high growth rate will be achieved by using stable precursors that do not have strong gaseous phase reaction, as opposed to metal organic precursors. The PI proposes also to modify the Hybrid Precursor Vapor Phase Epitaxy (HPVPE) shower head and gas delivery system that has been used with the metal organic gases. The grown materials and the LEDs built will be characterized and evaluated to optimize the proposed process. The technical prospects of the proposal are promising, since growth of thick layers is expected to result in the annihilation of dislocations. The proposed activity will advance the knowledge and understanding of the growth of high quality materials and devices, which are normally difficult to grow. This aspect of the work is expected to benefit technologies other than LEDs.