| US 7,525,304 B1 | ||
| Measurement of effective capacitance | ||
| Yiping Feng, Cupertino, Calif. (US); Jianou Shi, Milpitas, Calif. (US); and Xiafang Zhang, San Jose, Calif. (US) | ||
| Assigned to KLA-Tencor Corporation, San Jose, Calif. (US) | ||
| Filed on May 14, 2007, as Appl. No. 11/748,207. | ||
| Int. Cl. G01R 31/28 (2006.01); G01R 31/26 (2006.01) | ||
| U.S. Cl. 324—158.1 [324/765] | 25 Claims |
| 1. A method for determining an effective capacitance of a dielectric material, the method comprising the steps of:
forming first and second asymmetrical electrodes entirely within a field of the dielectric material, where the first electrode,
the second electrode, and the field of the dielectric material are co-planar, neither the first electrode nor the second electrode
are either electrically connected to ground or to each other,
applying a first charge Q on the first electrode,
measuring a first voltage change V1 on the first electrode,
measuring a second voltage change V2 on the second electrode,
depositing a second charge Q′ on the second electrode,
measuring a third voltage change V3 on the first electrode,
measuring a fourth voltage change V4 on the second electrode,
calculating a first ground capacitance Cg1 by,
Cg1=(V2Q′−V4Q)/(V2V3−V1V4),
calculating a second ground capacitance Cg2 by,
Cg2=(V3Q−V1Q′)/(V2V3−V1V4), and
calculating an inter-electrode capacitance Cie by,
Cie=V3Cg1/(V4−V3)=V2Cg2/(V1−V2).
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