Lai K, Kundhikanjana W, Kelly M, Shen Z X
Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, USA.
Rev Sci Instrum. 2008 Jun;79(6):063703. doi: 10.1063/1.2949109.
This paper presents a detailed modeling and characterization of a microfabricated cantilever-based scanning microwave probe with separated excitation and sensing electrodes. Using finite-element analysis, we model the tip-sample interaction as small impedance changes between the tip electrode and the ground at our working frequencies near 1 GHz. The equivalent lumped elements of the cantilever can be determined by transmission line simulation of the matching network, which routes the cantilever signals to 50 Omega feed lines. In the microwave electronics, the background common-mode signal is canceled before the amplifier stage so that high sensitivity (below 1 aF capacitance changes) is obtained. Experimental characterization of the microwave microscope was performed on ion-implanted Si wafers and patterned semiconductor samples. Pure electrical or topographical signals can be obtained from different reflection modes of the probe.
本文介绍了一种具有分离激励和传感电极的基于微加工悬臂的扫描微波探针的详细建模与特性分析。通过有限元分析，我们将针尖与样品之间的相互作用建模为在接近1GHz的工作频率下，针尖电极与地之间的小阻抗变化。悬臂的等效集总元件可通过匹配网络的传输线仿真来确定，该匹配网络将悬臂信号路由至50Ω馈线。在微波电子学中，背景共模信号在放大器阶段之前被消除，从而获得高灵敏度（低于1aF电容变化）。微波显微镜的实验特性分析是在离子注入硅片和图案化半导体样品上进行的。可以从探针的不同反射模式获得纯电信号或形貌信号。
