Low-Temperature Epitaxy of Gallium Nitride Thin Films

该奖项的研究目标是阐明导致高质量氮化镓(GaN)薄膜低温生长过程的机制，同时对衬底的热影响较小。该项目将开发一种激光辅助金属有机气相外延(L-MOVPE)工艺，该工艺可以在较低的衬底温度下增强GaN薄膜的外延化学反应。波长可调的CO2激光器，波长可调，从9.2到10.9微米，将被用来共振激发NH3分子，以促进化学反应，促进和最大限度地促进GaN外延过程。研究方法从研究前驱体分子共振激发的机理发展到在不同衬底上生长高质量的GaN外延层，以获得广泛的应用。成果包括用于合成GaN薄膜和其他功能材料的L-MOVPE系统、研究成果文献和工程学生教育。如果成功，这项研究成果将实现高能量耦合效率和对衬底的低热影响的高质量GaN薄膜的低温生长。在应用方面，该方法可以提供一种在蓝宝石或碳化硅衬底上进行GaN外延的新方法，可用于电子、光电子、化学和生物等领域。该项目的顺利完成将对激光控制化学过程的科学研究产生重大影响。实践上，该方法有望为低温合成高能量耦合效率的功能材料提供一条新的途径。研究成果还将有助于依赖高温化学工艺制造化合物半导体的相关行业提高生产率、节约能源和保护环境。研究生和本科生将从参与研究和课堂教学中受益。K-12学生和教师参与这一项目还将在大学和K-12学校之间建立新的伙伴关系。

The research objective of this award is to elucidate the mechanisms responsible for a low-temperature growth process of high-quality gallium nitride (GaN) films with low thermal impact on substrates. The project will develop a laser-assisted metalorganic vapor phase epitaxy (L-MOVPE) process that can enhance the chemical reactions in epitaxy of GaN thin films with low substrate temperatures. A wavelength-tunable CO2 laser, with a wavelength tunability from 9.2 to 10.9 micrometers, will be used to resonantly excite NH3 molecules for promoting chemical reactions to facilitate and maximize the GaN epitaxy process. The research approach progresses from mechanism study of resonant excitations of precursor molecules, to growth of high-quality GaN epilayers on different substrates for a wide range of applications. Deliverables include an L-MOVPE system configured for synthesis of GaN thin films and other functional materials, documentation of research results, and engineering student education.If successful, the results of this research will realize low-temperature growth of high-quality GaN films with high energy-coupling efficiency and low thermal impact on substrates. In terms of applications, the proposed method can provide a novel approach of GaN epitaxy on sapphire or SiC substrates for electronic, optoelectronic, chemical, and biological applications. The successful completion of this project will impact the scientific research of laser-controlled chemical processes by resonant excitation of precursor molecules. Practically, the proposed method is expected to provide a novel approach to synthesizing functional materials at lower temperature with high energy-coupling efficiency. The research results will also contribute to productivity improvement, energy savings, and environmental protection in related industries that rely on high-temperature chemical processes to fabricate compound semiconductors. Graduate and undergraduate students will benefit through involvement in the research and classroom instruction. The engagement of K-12 students and teachers in this project will also establish new partnerships between the University and K-12 schools.