Ultimate high frequency nanoresonator for RF signal processing

本研究的目的是制造和表征高频纳米机电谐振器（其基本谐振频率应在GHz范围内），使用隧道检测作为输出转导或电容耦合检测。第一个目标旨在证明高频纳米机电谐振器的可行性。为此，制作了一种基于叶片几何形状和电容耦合检测的谐振器。为了抑制寄生馈通，建立了一种基于混合的测量装置，并成功地演示了分别在1.104 GHz和2.5 GHz的基频共振和2^<和>模式的表征。在第二项研究中，使用工作在非接触模式下的多模原子力显微镜（AFM）来提取静电驱动硅桥谐振器（在10 MHz频率范围内）的机械响应。这种表征方法可以检测到埃级振动，随后将在扫描隧道显微镜（STM）模式下进行相同的实验。第三部分结合了项目的前两种方法，并讨论了射频纳米机电谐振器的制造与纳米定位致动器的集成，用于激励和隧道探测及其在TEM室中的表征。对谐振腔机械响应（f0=263kHz）的直接光学表征进行了验证，并对隧道尖端收缩过程中谐振腔I(V)特性进行了静态测量。目前正在研究动态模式下的测量，以证明隧道电流在谐振器谐振频率周围的调制。

The aim of this research concerns the fabrication and characterization of high frequency nanoelectromechanical resonators (fundamental resonance frequency of which should be in the GHz range), using either the tunnel detection as the output transduction, or capacitive coupling detection. The first objective aimed at demonstrating the feasibility of a high frequency nanoelectromechanical resonator (fo>1 GHz). For this purpose, a resonator based on a blade geometry, and capacitive coupling detection, has been fabricated. A mixing-based measurement set-up has been performed in order to suppress parasitic feedthrough, and characterization of fundamental resonance and 2^<nd> mode at respectively 1.104 GHz and 2.5 GHz has been successfully demonstrated. In a second study, a multimode Atomic Force Microscope (AFM) operating in non-contact mode was used in order to extract the mechanical response of electrostatically actuated silicon bridge resonators (in the 10 MHz frequency range). This characterization method allowed to detect angstrom-scale vibration and the same experiments will be performed afterwards in Scanning Tunnel Microscope (STM) mode. The third part combined the two first approaches of the project and deals with the fabrication of RF nano-electromechanical resonators integrated with nano-positioning actuators for both excitation and tunnel detection and its characterisation in TEM chamber. Direct optical characterisation of the resonator mechanical response (f0=263kHz) has been validated, and static measurements of the resonator I(V) characteristics during the tunnel tip retraction sequence has been performed. The measurements in dynamic mode are currently investigated in order to demonstrate the modulation of the tunnel current around the resonance frequency of the resonator.