CAREER: Fundamental Reliability Physics of MOS Devices Based on Deuterium Isotope Effects

职业：基于氘同位素效应的 MOS 器件的基础可靠性物理

• 批准号: 0093156
• 负责人: Zhi Chen
• 金额: $ 37.49万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0093156&HistoricalAwards=false
• 关键词: CAREER; Fundamental; Reliability; Physics; MOS

The proposed CAREER development program is an integrated research and teaching effort in MOStransistor reliability physics. The research component of this CAREER proposal focuses on fundamental study of mechanisms for the MOS device degradation and its isotope effect. The MOS transistor degradation is caused by Si-H (hydrogen) bond breaking at the SiO2-Si interface due to the energetic hot electrons. The current theory and experiments suggest that the Si-H bond breaking is caused by two competing processes: the excitation due to the energetic hot electrons and the de-excitation by energy coupling between the vibrational modes of the Si-H bonds and the phonon modes of the Si lattice. The energy coupling between the Si-D (deuterium) bonds and the Si lattice (TO phonon) is much more efficient than that between the Si-H bonds and the Si lattice. Therefore the Si-D bonds are more robust than Si-H bonds, which is the so-called isotope effect. Based on this principle, the deuterium-treated MOS transistors exhibit much longer hot-carrier lifetime (over 50 times) than the traditional hydrogen treatment. Evidence shows that there is a potential for further improvement of MOS transistor lifetime by over 100 times, if the mechanisms for degradation and its isotope effect are understood. The characterization of the efficient energy coupling between the two vibrational modes is that their frequencies are the same or very close. The study of the energy coupling is vital to understand the mechanisms for degradation and its isotope effect. The proposed research program will focus on two thrusts: 1) Degradation mechanisms for deep-submicron MOS transistors from fundamental point of view and 2) Study of dynamic hot-carrierdegradation of MOS devices in CMOS inverters. In the first thrust, I will use Raman and Infrared (IR)spectroscopy to study the vibrational modes of the Si-H and Si-D bonds. The ultimate goal of theresearch program is to develop predictive principles from which the processing can be designed toachieve the maximum lifetime improvement for MOS transistors. In the second thrust, I will study thedeuterium isotope effect for transistors under the dynamic stress or AC stress, because the transistors areoperating in AC conditions in the real circuits. The proposed research builds upon and expands theresearch work that the PI is already undertaking.The educational component of this CAREER program seeks support for development of a newexperimental course, integrated circuit device fabrication, and focused educational outreach activitiesin Appalachian communities (underrepresented groups). With the support from the State of Kentuckythrough the Research Challenge Trust Fund (RCTF), a Device Fabrication Facility is under constructionat UK. A new experimental course focused on fabrication of integrated circuit devices will be developed,which is equivalent to similar courses in other universities in the US. The class is a hands-on lab coursewhere students have the opportunity to build semiconductor devices for integrated circuits. This class willfirst be taught in the Fall 2001 for senior undergraduate students and graduate students. Themultidisciplinary nature of this program will provide students with a unique environment for researchand learning. The goal is to build bridges between these traditional disciplines such as physics, materialsscience, and electrical engineering by conducting research and teaching through an integrated approach.The other component of the educational objectives involves the educational outreach activities targetedfor high school students from Eastern and Southern Kentucky including Appalachian communities. Oneof the objectives is to encourage those high school students to pursue high-tech career by presenting aseries of seminars in microelectronics. Another one is to offer an experimental project to teach them tobuild some useful digital circuits. The high school students will be recruited from the already establishedprogram, the Rogers Scholar Program organized by the Center for Rural Development, which the PIalready participates.

建议的职业发展计划是一个集成的研究和教学努力在MOS晶体管可靠性物理。 该职业计划的研究部分侧重于MOS器件退化及其同位素效应机制的基础研究。MOS晶体管的退化是由于高能热电子在SiO2-Si界面处导致Si-H（氢）键断裂而引起的。目前的理论和实验表明，Si-H键断裂是由两个竞争过程引起的：由于高能热电子的激发和Si-H键的振动模式和Si晶格的声子模式之间的能量耦合的去激发。Si-D（氘）键与Si晶格（TO声子）之间的能量耦合比Si-H键与Si晶格之间的能量耦合有效得多。因此，Si-D键比Si-H键更坚固，这就是所谓的同位素效应。基于这一原理，氘处理MOS晶体管的热载流子寿命比传统的氢处理长得多（超过50倍）。有证据表明，有一个潜在的进一步提高MOS晶体管寿命超过100倍，如果退化及其同位素效应的机制是了解。两个振动模式之间的有效能量耦合的特征在于它们的频率相同或非常接近。能量耦合的研究对于理解降解机理及其同位素效应具有重要意义。 本论文的研究方向主要集中在两个方面：1）从基础理论的角度研究深亚微米MOS晶体管的退化机理; 2）研究CMOS反相器中MOS器件的动态热载流子退化。在第一部分中，我将使用拉曼和红外（IR）光谱来研究Si-H和Si-D键的振动模式。该研究计划的最终目标是开发预测原则，从该原则可以设计工艺，以实现MOS晶体管寿命的最大改善。在第二部分中，我将研究晶体管在动态应力或交流应力下的氘同位素效应，因为在真实的电路中，晶体管工作在交流条件下。拟议的研究建立在并扩大了PI已经在进行的研究工作的基础上。该CAREER计划的教育部分寻求对开发新的实验课程、集成电路器件制造和阿巴拉契亚社区（代表性不足的群体）的重点教育推广活动的支持。在英国国家研究挑战信托基金（RCTF）的支持下，一个器件制造设施正在建设中。将开发一个新的实验课程，重点是集成电路器件的制造，这相当于在美国其他大学的类似课程。这门课是一门动手实验课，学生有机会为集成电路制造半导体器件。这门课将于2001年秋季开始，面向高年级本科生和研究生开设。该计划的多学科性质将为学生提供一个独特的研究和学习环境。目标是通过综合的方法进行研究和教学，在物理学、材料科学和电气工程等传统学科之间建立桥梁。教育目标的另一个组成部分是针对包括阿巴拉契亚社区在内的肯塔基州东部和南部高中生的教育推广活动。目的之一是通过举办一系列的微电子研讨会，鼓励这些高中生从事高科技职业。另一个是提供一个实验项目，教他们建立一些有用的数字电路。高中生将从已经建立的计划中招募，罗杰斯学者计划由农村发展中心组织，PI已经参与。