Figure 4

Schematic and pictures of “surface trap”. (a) Schematic of a surface trap. The red and blue rectangles indicate RF and DC electrodes respectively. The curved arrows denote the direction of electric field when RF voltage is positive. Note that all electrodes are laid on the same plane. (b) Optical image of the surface trap of the Sandia National Laboratory (SNL) group, which has a double metal layer on Si substrate [58]. (c) Scanning electron micrograph of the surface trap of the SNL group [59].