Radiation Response and Defect Dynamics in Strained Si

技术：本项目研究应变在离子辐照和退火硅中的损伤级联形成和随后的缺陷聚集中的作用。该方法侧重于利用分子束外延技术在不同应变下生长硅。团簇离子轰击将用于研究应变硅的非晶化机制。在一项使用单体离子辐照的平行研究中，将使用掺硼硅超晶格结构来检测硅间隙组织在辐照后的热退火过程中的通量。测量的瞬时间隙过饱和度将被用作Ostwald熟化的逆模型的输入，以获得作为团簇大小函数的缺陷团簇的形成能。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缺陷的发展。非技术性：该项目解决了材料科学中具有高度技术相关性的热门领域的基础研究问题。预测应变硅中的工艺参数的能力对于推广应变技术、优化器件制造中的掺杂和退火工艺以及在涉及粒子辐照的恶劣环境中评估器件的可靠性至关重要。该项目将研究和教育结合在一起，并通过以下活动进行推广：(1)增加少数群体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、教学和课程开发整合在一起，促进材料科学前沿的公共学习；(4)发展德克萨斯农工大学离子与材料研究中心，并将其作为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.