Radiation Response and Defect Dynamics in Strained Si

技术支持：本计画探讨应变在离子辐照及退火矽中，于损伤级联形成及后续缺陷聚集中所扮演的角色。该方法强调使用分子束外延在不同应变下的Si的生长。采用团簇离子轰击的方法研究应变硅的非晶化机制。在使用单体离子辐照的平行研究中，硼掺杂的Si超晶格结构将用于检测辐照后热退火期间Si材料的通量。所测得的瞬态间隙过饱和将被用作输入到逆建模的奥斯特瓦尔德熟化，以获得作为集群大小的函数的缺陷集群的形成能量。该项目将实验方法与分子动力学模拟相结合，旨在全面了解应变硅中的缺陷发展情况。非技术性：该项目致力于解决与技术高度相关的材料科学领域的基础研究问题。预测应变硅工艺参数的能力对于促进应变技术、优化器件制造中的掺杂和退火工艺以及评估器件在涉及粒子辐照的恶劣环境中的可靠性至关重要。该项目将研究和教育结合起来，并通过以下活动开展外联活动：（1）增加少数民族对新兴材料研究的参与;（2）开发课程;（3）创建电子学习资源，将研究、教学和课程开发结合起来，以促进材料科学前沿领域的公共学习;（4）在得克萨斯州农工大学建立离子材料研究中心，并将其用作跨学科研究和教学的平台。

Technical: This project investigates the role of strain in damage cascade formation and subsequent defect clustering in ion irradiated and annealed Si. The approach places emphasis on the growth of Si under different strain using molecular beam epitaxy. Cluster ion bombardment will be used to study amorphization mechanisms of the strained Si. In a parallel study using monomer ion irradiation, boron doped Si superlattice structures will be used to detect the flux of Si interstitials during post-irradiation thermal annealing. The measured transient interstitial supersaturation will be used as input to an inverse modeling of Ostwald ripening to obtain formation energies of defect clusters as a function of cluster size. Combining the experimental approaches with molecular dynamics simulations, the project aims for a comprehensive picture of defect development in strained silicon.Non-technical: This project addresses basic research issues in a topical area of materials science with high technological relevance. The capability to predict processing parameters in strained silicon is critical to promoting strain technology, optimizing the doping and annealing process in device fabrication, and evaluating device reliability in harsh environments involving particle irradiation. The project integrates research and education, and conducts outreach through the following activites: (1) increase minority participation in emerging materials research; (2) develop curricula; (3) create e-learning resources to integrate research, teaching and curriculum development for promoting public learning in frontiers of materials science; and (4) develop the Center of Ion & Materials Research at Texas A&M University and use it as a platform for interdisciplinary research and teaching.