New scalable microfabrication method for surface ion traps and experimental results with trapped ions

This paper presents a new microfabrication method for surface ion traps and experimental results with trapped ions. Fabricating ion trap chips is a very formidable task because the top electrodes are vertically spaced more than 10 μm from the bottom electrodes with an indented dielectric layer in the middle. Previous ion traps were fabricated using TEOS timed etch or tungsten sacrificial etch techniques. This paper presents a new microfabrication method, using copper as a sacrificial material for an aluminum-oxide-aluminum ion trap structure. Using the developed method the overhang dimensions of the top aluminum electrodes can be accurately controlled. Fabricated ion trap chips are installed in a 1 × 10^-11 Torr vacuum environment for ion trapping experiments. Successful results in trapping strings of ¹⁷¹Yb⁺ and ¹⁷⁴Yb⁺ ions as well as manipulating ¹⁷¹Yb⁺ ions for qubit operation are demonstrated.