GOALI/Collaborative Research: Understanding Cracking and Defect Formation During AlN Crystal Growth

CMMI - 0928556 - GOALI/协作研究：了解 AlN 晶体生长过程中的裂纹和缺陷形成 该提案将使用 2009 年美国复苏和再投资法案（公法 111-5）提供的资金授予，并符合 3 月 20 日题为“确保负责任地支出复苏法案资金”的白宫备忘录第 2 节中规定的要求， 2009 年。作为认识到的项目官员，我还确认该提案不支持恢复法案 A 部分第 1604 节中描述的项目。这项研究的目标是 i) 了解并 ii) 创建氮化铝 (AlN) 单晶在加工过程中裂纹萌生和整体晶体质量演变的预测方法。 AlN 具有出色的电学和热学性能，特别适合高功率、高频、节能的电子和光子器件，例如发光二极管 (LED) 和激光二极管，但目前 AlN 的使用受到高生产成本的限制。该提案的工业合作伙伴 Crystal IS 开发了一种用于生长大型 AlN 晶体的新技术 - 直径可达 50 毫米。然而，这些大晶体经常由于材料从高达 2300°C 的生长温度冷却时产生的应力而破裂。在该项目中，来自康奈尔大学和伦斯勒大学的负载材料应力测量和模拟领域的专家团队将研究氮化铝作为“结构”材料。高能 X 射线将用于在加载测试样本时“查看”测试样本深处的 AlN 晶体结构。通过将模拟与实验结果相匹配，将确定与强度、刚度和抗断裂性相关的关键的与温度相关的机械性能。这些信息将用于晶体生长过程模型中，以预测给定生长条件下的晶体质量。这项工作将指导晶体生长过程设计人员，以便可以生产出大型、高质量的晶体。这项工作将被纳入参与机构的教育计划中。产业合作将提供极好的学习机会。开发的任何实验功能都将驻留在 X 射线束线上，并可供其他用户使用。

CMMI - 0928556 - GOALI/Collaborative Research: Understanding Cracking and Defect Formation During AlN Crystal Growth This proposal will be awarded using funds made available by the American Recovery and Reinvestment Act of 2009 (Public Law 111-5), and meets the requirements established in Section 2 of the White House Memorandum entitled, Ensuring Responsible Spending of Recovery Act Funds, dated March 20, 2009. I also affirm, as the cognizant Program Officer, that the proposal does not support projects described in Section 1604 of Division A of the Recovery Act.The objectives of this research are to i) gain an understanding of and ii) create a predictive methodology for crack initiation and overall crystal quality evolution for Aluminum Nitride (AlN) single crystals during processing. AlN has outstanding electrical and thermal properties making it particularly well-suited for high power, high frequency, energy efficient electronic and photonic devices, such as light emitting diodes (LEDs) and laser diodes, but the use of AlN is currently limited by the high production cost. Crystal IS, the industrial partner on this proposal, has developed a new technology for growing large AlN crystals - up to 50 mm in diameter. However, these large crystals often crack due to stresses that arise when the material is cooled from its growth temperature as high as 2300C. In this project, a team of experts in the fields of stress measurement and simulation of loaded materials from Cornell and Rensselaer will study AlN as a "structural" material. High energy X-rays will be used to "see" the crystal structure of the AlN deep inside a test specimen as it is loaded. By matching simulations to the experimental results, key temperature-dependent mechanical properties, related to strength, stiffness and fracture resistance will be determined. This information will be used in a crystal growth process model to predict crystal quality for given growth conditions.This work will guide crystal growth process designers so that large, high quality crystals can be produced. This work will be integrated into educational programs at the participating institutions. The industrial collaboration will provide excellent learning opportunities. Any experimental capabilities developed will reside at the x-ray beamline and become available to other users.