Mechanisms of Extended Defect Nucleation During PVT Growth of Silicon Carbide

碳化硅PVT生长过程中扩展缺陷形核的机制

• 批准号: 9903702
• 负责人: Marek Skowronski
• 金额: $ 46.62万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9903702&HistoricalAwards=false
• 关键词: Mechanisms; Extended; Defect; Nucleation; During

This GOALI project represents a collaborative effort between researchers at Carnegie Mellon University, SUNY (Stony Brook), and Cape Simulations Inc., together with crystal growth companies: Cree Research, Inc., Epitronics, Inc., Northrop Grumman Corp., Airtron-Litton Corp., and II-VI, Inc. to investigate nucleation mechanisms of crystalline defects in SiC. The objectives of the project are to advance the understanding of processes responsible for nucleation and evolution of extended defects in SiC boules. In particular basal plane and screw dislocations, stacking faults, micropipes, and low angle domain boundaries will be investigated. The approach consists of three thrusts:(i) Modeling of silicon carbide Physical Vapor Transport growth with emphasis on thermoelastic stresses at different stages of growth. Local stress fields around small second phase inclusions common in PVT growth will also be modeled. (ii) SiC PVT growth experiments will be performed in a small scale PVT system in carefully optimized conditions selected to minimize defect nucleation. Critical process parameters will be adjusted to test models of defect nucleation and multiplication. Growth will be interrupted at different stages (in particular early seeding stages), followed by ex situ structural characterization. (iii) Structural characterization of SiC crystals will be performed by synchrotron white beam x-ray topography (SWBXT), Atomic Force Microscopy (AFM), transmission electron microscopy, etching and high resolution x-ray diffraction (HRXRD). Density of basal plane dislocations and total bending of basal plane will be determined and correlated with macroscopic stress distributions. Nucleation of screw dislocations at early stages of growth and their association with stacking disorder and inclusions will be observed by x-ray topography and TEM. Misorientation components across low angle grain boundaries revealed by etching will be measured by HRXRD and their origin interpreted.%%%The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute basic materials science knowledge at a fundamental level to bulk crystal growth important to electronics/photonics. The basic knowledge and understanding gained from the research is expected to contribute to improving the cost, perform-ance and stability of advanced devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. Graduate students participating in this project will gain multifaceted experience collaborating with team members. They will work with and improve process simulation tools, grow and characterize SiC crystals, take part in technology transfer, and will be exposed to work in both academic and industrial environments. The project is co-supported by the DMR/Electronic Materials program and the MPS OMA(Office of Multidisciplinary Activities).***

这个守门员项目代表了卡内基·梅隆大学（Carnegie Mellon University），纽约州立大学（Stony Brook）（Stony Brook）和Cape Simulations Inc.的研究人员与水晶增长公司（Crystal Growth Companies）：Cree Research，Inc。，Epitronics，Inc。，Northrop Grumman Corp.，Airtron-Litton Corp.和II-Litton Corp.和II-VI，II-VI，II-VI。调查CyreTiency Sy的SIC，该项目的目标是提高对SIC BOULES扩展缺陷的成核和演变的过程的理解。特别是基础平面和螺钉位错，堆叠断层，微型调子和低角度结构域边界。该方法由三个推力组成：（i）碳化硅物理蒸气转运生长的建模，重点是不同生长阶段的热弹性应力。还将建模PVT生长中常见的小型第二相夹杂物周围的局部应力场。 （ii）SIC PVT生长实验将在小规模的PVT系统中进行精心优化的条件，以最大程度地减少缺陷成核。关键过程参数将调整为缺陷成核和乘法的测试模型。生长将在不同阶段（特别是早期播种阶段）中断，其次是原位结构表征。 （iii）SIC晶体的结构表征将通过同步型白束X射线形貌（SWBXT），原子力显微镜（AFM），透射电子显微镜，蚀刻和高分辨率X射线衍射（HRXRD）进行。基础平面位错的密度和基础平面的总弯曲将与宏观应力分布相关。 X射线地形和TEM将观察到生长早期及其与堆叠障碍和夹杂物的关联的螺钉位错的成核。蚀刻揭示的低角度晶界的不良方向成分将由HRXRD及其来源解释。%%％该项目解决了具有很高潜在技术相关性的材料科学局部研究领域的基础研究问题。这项研究将在基本水平上为基本材料的知识提供对电子/光子学重要的批量晶体生长的基本知识。预计从研究中获得的基本知识和理解将有助于提高先进设备的成本，性能和稳定性。 该计划的一个重要特征是通过培训学生在根本和技术意义上的领域中培训研究和教育。参加该项目的研究生将获得与团队成员合作的多方面经验。他们将使用并改善过程模拟工具，成长和表征SIC晶体，参与技术转移，并将在学术和工业环境中进行工作。该项目由DMR/电子材料计划和国会议员OMA（多学科活动办公室）共同支持。***