Radiation Response and Defect Dynamics in Strained Si

技术：本项目研究了应变在离子辐照和退火Si中损伤级联形成和随后缺陷聚集中的作用。该方法着重于利用分子束外延在不同应变下生长Si。用簇离子轰击法研究应变硅的非晶化机理。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过程中Si间隙的通量。测量的瞬态间隙过饱和度将用作奥斯特瓦尔德成熟逆模型的输入，以获得缺陷簇的形成能作为簇大小的函数。将实验方法与分子动力学模拟相结合，该项目旨在全面了解应变硅中的缺陷发展情况。非技术：该项目涉及材料科学领域的基础研究问题，具有很高的技术相关性。预测应变硅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。该项目将科研与教育相结合，并通过以下活动开展外展活动：(1)增加少数民族对新兴材料研究的参与；(2)制定课程；(3)创建电子学习资源，整合研究、教学和课程开发，促进材料科学前沿的公共学习；(4)建设德克萨斯农工大学离子材料研究中心，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.