FRG: Materials Physics and Chemistry of Light-Ion-Exfoliation of Single-Crystal Ferroelectric Films

FRG：单晶铁电薄膜光离子剥离的材料物理和化学

• 批准号: 0405145
• 负责人: Richard Osgood
• 金额: $ 71.77万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0405145&HistoricalAwards=false
• 关键词: FRG; Materials; Physics; Chemistry; Light

New knowledge and greater fundamental understanding of exfoliation of ferroelectric thin films by deep implantation of light ions (He and H), followed by selective chemical etching are sought. The exfoliation process yields single-crystal films of ferroelectric materials, such as lithium niobate, lead zirconate, and strontium titanate, but fundamental materials science knowledge of the process is lacking. This project seeks basic information about how high-energy ion-based processes alter narrow spatial regions in single-crystal complex oxides, as well as determination of process issues such as vertical and lateral patterning resolution and crystal quality. The exfoliation process being studied here differs from that seen in semiconductors since lift-off proceeds by highly selective wet etching of the heavily implanted region. Research questions to be addressed regarding this process include: What physical mechanism mediates the high selectivity of the etching process? What are the solid-state chemical changes in the implantation region following He or H implantation of ferroelectrics crystals? What is the role of interstitial-mediated stress in the implantation region? Are nanocavities formed as in H-implanted Si? To what extent is the chemical stoichiometry of the surface changed following the exfoliation process? The approach is to investigate basic materials chemistry and physics of deeply, heavily implanted ferroelectric crystals and subsequent exfoliation from this material. In particular, the project will involve examination of 1) changes in crystal lattice, i.e. defects, nanocavities, interstitial concentration, in ferroelectric crystals; 2) changes in crystal chemistry, i.e. the composition and formation of volatile interstitial species and local-stress-induced chemical dissolution reactions in the implant region; and 3) compositional changes in, and recovery of, the exfoliated complex-oxide surface-following heavy implantation of light ions in ferroelectric crystals. %%%The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new understanding and capabilities in electronics/photonics and promotes the integration of research and education. The project is interdisciplinary spanning aspects of electrical engineering, applied physics, chemistry and materials science with undergraduate and graduate students working together to conduct both fundamental and applied research in new materials, materials processing techniques, and devices. The project is highly collaborative enabling PI/co-PIs and students to collaborate via extended visits and shorter trips with a major National Laboratory, Brookhaven, and across two New York State universities, Columbia and SUNY Albany, each of which offers unique facilities and experiences. Collaborative research interactions with other internal and external research groups, such as those at Columbia's MRSEC and Rutgers, are also anticipated. ***

新的知识和更大的基本理解剥离的铁电薄膜的深注入轻离子（He和H），然后通过选择性化学蚀刻寻求。剥离过程产生铁电材料的单晶膜，例如锂钛酸盐、锆酸铅和钛酸锶，但缺乏该过程的基本材料科学知识。该项目寻求有关高能离子工艺如何改变单晶复合氧化物中狭窄空间区域的基本信息，以及确定垂直和横向图案分辨率和晶体质量等工艺问题。这里正在研究的剥离过程不同于在半导体中看到的剥离过程，因为剥离是通过高度选择性的湿法蚀刻重注入区来进行的。关于这个过程中要解决的研究问题包括：什么物理机制介导的蚀刻过程的高选择性？铁电晶体注入He或H后，注入区的固态化学变化是什么？ 胚胎介导的应力在着床区的作用是什么？纳米空穴形成的H-注入硅？剥落过程后表面的化学计量发生了多大程度的变化？该方法是研究基本材料的化学和物理的深度，重注入铁电晶体和随后的剥离从这种材料。特别是，该项目将涉及检查1）晶格的变化，即铁电晶体中的缺陷，纳米腔，间隙浓度; 2）晶体化学的变化，即挥发性间隙物质的组成和形成以及注入区域中局部应力诱导的化学溶解反应;和3）在铁电晶体中重注入轻离子后，剥落的复合氧化物表面的组成变化和恢复。 该项目解决了具有高技术相关性的材料科学专题领域的基础研究问题。该研究将在基础层面上为电子/光子学的新理解和能力贡献基础材料科学知识，并促进研究和教育的整合。该项目是跨学科的跨越电气工程，应用物理，化学和材料科学方面的本科生和研究生一起工作，进行新材料，材料加工技术和设备的基础和应用研究。该项目是高度协作，使PI/co-PI和学生通过延长访问和较短的行程与一个主要的国家实验室，布鲁克海文，并在两个纽约州立大学，哥伦比亚和纽约州立大学奥尔巴尼，其中每一个提供独特的设施和经验。与其他内部和外部研究小组，如哥伦比亚的MRSEC和罗格斯大学的合作研究互动，也是预期的。***