Advanced Nanoelectronic Device Design with Atomistic Simulations

现代CPU由数十亿个纳米晶体管组成。为了使这些纳米晶体管可用，它们的性能特性变化最小是至关重要的。然而，确保数十亿个晶体管的关键器件特性几乎没有变化是一个巨大的挑战。在现代纳米晶体管的规模上，即使结构几何形状的原子化变化也会对整体器件性能产生严重影响。该项目将使用Blue Waters领先计算系统来派生新的模型，以便能够在设计的关键里程碑对现代纳米设备进行有效的可靠性预测。这将使基于科学和工程的探索路线图结束的设备选项，使我们的国家保持领先的半导体技术。该项目将使用与半导体行业共同开发的软件NEMO5来提出具体的下一代纳米晶体管。此外，许多学生将参与到这个项目中来，为我国下一代劳动力的教育做出贡献。最先进的纳米设备具有几十个或一百个原子的特征长度。在这些维度中，不可避免的几何波动，即使是一个或几个原子的数量级，也会对性能产生重大影响。因此，现代器件的设计必须考虑纳米结构对波动的敏感性，以及从前几代器件中已知的其他重要参数。声子，即原子在晶格位置周围的振动，在这个尺度上也对器件的性能有严重的影响。由于只有几个原子参与器件输运，电子与声子的相互作用基于全量子输运方法，该方法涵盖了小尺寸相干效应，如隧道效应、限制效应以及器件缺陷上的非相干散射。尽管处理这一问题的量子传输方法是众所周知的，但他们的解决方案在数字上是出了名的昂贵。该项目有两个重点：1)由于包括散射在内的最新物理模型对下一代晶体管性能的不确定性预测；2)半导体-金属互连电阻的精确紧凑模型的开发。

Modern CPUs are composed of billions of nanotransistors. To make these nanotransistors usable, it is essential that their performance characteristics vary minimally. However, ensuring that billions of transistors have little variation in their critical device characteristics is a huge challenge. At the scale of modern nanotransistors, even atomistic variations of the structure geometry can have a severe influence on overall device performance. This project will use the Blue Waters leadership computing system to derive new models to enable efficient reliability predictions of modern nanodevices at crucial milestones in their design. This will enable scientific and engineering based exploration of the end-of-the-roadmap device options, allowing our nation to remain the leader in semiconductor technologies. The project will use NEMO5, a software co-developed with the semiconductor industry, to propose concrete, next generation nanotransistors. Furthermore, many students will be involved in the project, contributing to the education of our nation's future generation workforce.The state-of-the art nanodevices have characteristic lengths in the order of tens or one hundred of atoms. In these dimensions, unavoidable geometry fluctuations, even if they are of the order of one or a few atoms, can significantly impact performance. Thus, the design of modern devices has to consider the sensitivity of the nanostructure to fluctuations, as well as other important parameters that are known from earlier device generations. Phonons, i.e. vibrations of atoms, around their lattice sites have a severe impact on the device performance at this scale as well. Since only a few atoms are involved in the device transport, the interaction of electrons with phonons is based on a full quantum transport method that covers small-size coherent effects such as tunneling and confinement as well as incoherent scattering on device imperfections. Although quantum transport methods that handle this are well known, their solution is notoriously numerically expensive. This project has two focal points: 1) uncertainty prediction of next-generation transistor performance due to state-of-the-art physics models including scattering and 2) accurate compact model development of semiconductor-metal interconnect resistance.