Far UV Spectroscopic Ellipsometry of Electronic Materials

这个项目的目标是在成功建造远紫外光椭偏仪的基础上，应用这个工具来提高对新材料和旧材料变得新的重要的PI的理解。PI打算通过与来自全国许多学科的各种同事进行合作研究来分享这一新的下一代工具的影响。该项目应该在OGI培训至少一名博士生，并协助许多地方的其他人的研究努力。这项工作将强调具有技术重要性的材料，并将重点放在拟议的高K栅电介质上，如HfO2。该系统提供了比传统系统(Hv 6.5 eV)显著增加的光子能量极限(Hv 9 EV)，从而使PI能够检查只有在同步辐射光源下才能访问的临界点结构。这一能量范围尤其影响了对宽带隙材料的研究；HfO2等介质材料和金刚石、碳化硅、GaN等宽禁带半导体材料都引起了人们的直接和迫切的兴趣。这使得PI能够影响当前的半导体行业，寻找材料来取代SiO_2作为CMOS工艺中的栅电介质。它允许PI研究抛光的碳化硅表面的表面损伤层，因为可用的较高能量也提供了对表面膜的更高的敏感性。他寻求资金，以继续将这一工具应用于此类研究。他与几个团体建立了伙伴关系，这些团体试图利用拟议研究提供的信息来加强他自己的努力。具体的重点领域将是高？未来的cmos技术中的电介质。这一国际努力是由通过薄势垒层的隧道开始施加的对CMOS比例的基本限制所推动的。这种量子力学效应似乎限制了SiO_2基栅极电介质的使用，即使增加了氮化物层，厚度也不能超过1.0 nm，并将从根本上影响本十年的器件设计和生产。事实上，2001年版的国际半导体技术路线图预计，到2005年，这些材料将成为低功耗逻辑芯片所需的材料。PI已经将他目前的系统应用到其中一些材料的研究中，并确定在某些明确的领域，他扩展了光子能量范围提供了新的和独特的信息。他试图为许多候选材料建立一个介电响应数据库，并将这个数据库用于研究这些沉积在硅衬底上的薄膜。他的合作伙伴关系允许他研究电子束沉积、喷射气相沉积、分子束外延和原子束沉积所沉积的材料。这些证词的细节可以强烈地改变界面和电影本身--就像他已经为HfO2所展示的那样。同时，确定这些候选材料中涉及过渡金属和稀土元素的d能级的冲击吸收将对含有这些材料的晶体管的电学性能产生什么影响是至关重要的。PI的研究将有助于阐明这些能级的位置和性质。

0218288FreeoufThe objectives of this project are to build upon the successful construction of a Far UV spectroscopic ellipsometer and apply this tool to improve the PIs understanding of new materials - and of older materials becoming newly important. The PI intends to share the impact of this new, next-generation tool by collaborative research with a variety of colleagues from many disciplines throughout the country. The project should train at least one PhD student at OGI and assist the research efforts of others at many locations. This effort will emphasize materials of technological importance and concentrate upon proposed high-K gate dielectrics such as HfO2.This system offers a substantially increased photon energy limit (hv 9 eV) over conventional systems (hv 6.5 eV), thereby permitting us the PI to examine critical point structures that would otherwise only be accessible at a synchrotron radiation source. This energy range especially impacts studies of wide band gap materials; both dielectrics such as HfO2 and wide band gap semiconductors such as diamond, SiC, and GaN are of immediate and urgent interest. This permits the PI to impact the current semiconductor industry search for materials with which to replace SiO2 as the gate dielectric in CMOS technology. It has permitted the PI to study surface damage layers on polished SiC surfaces, since the higher energies available also offer increased sensitivity to surface films. He seeks funding to continue to apply this instrument to such studies. He has partnerships with several groups that seek to strengthen his own efforts by using the information available from the proposed studies.The specific area of emphasis will be on high-? dielectrics for future CMOS technologies. This international effort is driven by the fundamental limitation upon CMOS scaling that is imposed by the onset of tunneling through a thin barrier layer. This quantum mechanical effect appears to restrict the use of SiO2 based gate dielectrics, even with the addition of nitride layers, to greater than 1 .0 nm thickness, and will fundamentally impact device design and production in this decade. In fact, the 2001 editio of the International Technology Roadmap for Semiconductors envisions these materials being required by 2005 for low power logic chips. The PI has already applied his current system to the study of some of these materials and established that there are clear areas where he extended photon energy range provides new and unique information. He seeks to build a database of dielectric response for many of the candidate materials, and to use this database in the study of these films as deposited upon silicon substrates. His partnerships permit him to study materials deposited by e-beam, jet vapor deposition, molecular beam epitaxy, and atomic beam deposition. The details of these depositions can strongly alter the interface and the film itself - as he has demonstrated for HfO2 already. At the same time it is crucial to ascertain what impact absorption involving the d-levels of transition metal and rare earth elements in these candidate materials will have upon the electrical properties of transistors containing those materials. The PI's studies will help to clarify the location and properties of these energy levels.