摘要 |
The structure of a high-Q inductor applied in a monolithic circuit according to the invention comprises a plurality of spiral metal lines and a plurality of dielectric layers, each dielectric layer formed between two adjacent spiral metal lines. Furthermore, via plugs are formed in each dielectric layer to electrically connect two adjacent spiral metal lines. A spiral air trench is formed along the spacing of the spiral metal lines in the dielectric layers. Therefore, the 3D-structure of the inductor of the invention can greatly reduce the series resistance thereof without widening the spiral metal lines. In addition, the spiral air trench, filled with air which has a lower dielectric constant, can efficiently reduce the parasitic capacitance between the spacing of the spiral metal lines. As a result, the inductor of the invention has a higher quality factor at a proper RF operating frequency region.
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