Figure 1.

Schematic drawings illustrate the tantalum (green) comb structure fabrication method. (a) Patterns were transferred to the silicon oxide films using lithography and plasma etching techniques. (b) Tantalum seed and copper films were deposited on the etched patterns. (c) Excess copper was removed by using the chemical-mechanical polishing techniques. (d) Remaining copper was stripped with nitric acid. The comb structure contains line (L) and trench (T) of equal widths. All trenches had the same depth (D).