Vacuum Scanning Microwave Microscopy for quantitative characterization of sub-10 nm and atto-Farad scale capacitors and memories

由于器件尺寸将继续缩小到20 nm以下，并且市场上已经出现了新型纳米器件，因此对其电子结构的准确表征和详细了解至关重要，但也具有挑战性。特别是，纳米电容器和隧道势垒，在大多数存储器中的构建块，是非常难以表征，由于在阿托法拉范围内的电容。最近开发的扫描微波显微镜（SMM）几乎显示出这样的能力，但它们的操作，仅限于空气或氮气环境，导致难以定量表征，由于众所周知的寄生水弯月面的贡献。其他扫描探针显微镜（原子力显微镜，开尔文力显微镜，扫描隧道显微镜和其他），已经提出了真空或超高真空版本，以消除这种寄生效应，但也保护敏感器件。在这个项目中，我们建议建立，第一次，真空下的SMM（VACSMM），将联合收割机纳米接触，成像，SEM观察和FIB原子力显微镜尖端的细化，降低了电寄生效应、DC和RF测量。它将配备一个干涉仪，允许aF电容灵敏度。亚10纳米电容器和存储器将与芯片上的校准工具包，以实现对这些设备的定量电子研究。特别是，将对电容、电导和开关速率进行统计研究（对于OxRAM存储器）和模型/理论将被提出（有限元建模、S参数分析模型、原子开关物理学）。制造的VACSMM将共存于SEM内，自动化方法将作为一种观点，使该装置成为一种可能的工业工具，纳米电容器和存储器表征在顶部电极制造之前。这个德法联合项目是一个很好的机会，结合联合收割机在纳米器件制造和SMM（法国合作伙伴）和自制的真空原子力显微镜/SEM，包括软件和机器人自动化工具（德国合作伙伴）的互补专业知识。

As device scaling will continue below 20 nm and novel nanodevices already appear on the market, accurate characterization and detailed understanding of their electronic structure is essential, yet challenging. In particular, nanocapacitors and tunnel barriers, that are building blocks in most memories, are extremely difficult to characterize due to capacitances in the atto-Farad range. Recently developed Scanning Microwave Microscopes (SMMs) are almost showing such abilities but their operation, only limited to air or nitrogen environment, lead to difficult quantitative characterization due to well-known parasitic water meniscus contribution. Other Scanning Probe Microscopes (Atomic Force Microscopes, Kelvin Force Microscope, Scanning Tunneling Microscopes and other), have been proposed with vacuum or ultra-high vacuum versions to remove this parasitic effect, but also to protect sensitive devices.In this project, we propose to build, for the first time, a SMM under vacuum (VACSMM) that will combine nanoscale contact, imaging, SEM observation and FIB refining of AFM tips, reduced electrical parasitics, DC and RF measurements. It will be equipped with an interferometer allowing aF capacitance sensitivity. Sub-10 nm capacitors and memories will be fabricated with an on-chip calibration kit to achieve a quantitative electronic study on these devices. In particular, statistical studies will be performed on the capacitance, conductance and switching rates (for OxRAMs memories) and models/theory will be proposed (finite element modeling, analytical models for S parameters, physics of atomic switches).The fabricated VACSMM will coexist inside a SEM, automation methods will be developed as a perspective to make this apparatus a possible industrial tool for nanoscale capacitors and memory characterization before top electrode fabrication. This German-French joint project is a great opportunity to combine complementary expertise in nanodevices fabrication and SMM (French partner) and self-made Atomic Force Microscope/SEM under vacuum including software and robotic automation tools (German partner).