Inductor formed in an integrated circuit
View Patent ↗An inductor formed within an integrated circuit and a method for forming the inductor. The inductor comprises an underlying layer of aluminum formed in a first metallization layer and patterned and etched into the desired shape. In one embodiment the aluminum line comprises a spiral shape. According to a damascene process, a conductive runner, preferably of copper, is formed in a dielectric layer overlying the aluminum line and in electrical contact therewith. The aluminum line and the conductive runner cooperate to form the inductor. In another embodiment the aluminum line and the conductive runner are formed in a vertically spaced-apart orientation, with tungsten plugs or conductive vias formed to provide electrical connection therebetween. A method for forming the inductor comprises forming an aluminum conductive line and forming a conductive runner over the conductive line.
1. A method for forming an inductor in a semiconductor integrated circuit, the method comprising:
forming a conductive line in a metallization layer;
forming a first dielectric layer overlying the conductive line;
forming conductive structures in the first dielectric layer;
forming a conductive pad overlying and in electrical communication with one of the conductive structures and a terminal end of the conductive line;
forming a second dielectric layer overlying the first dielectric layer and the conductive pad;
forming a trench in the second dielectric layer; and
forming a conductive runner in the trench, wherein the conductive runner is in conductive communication with the conductive line through the conductive structures, and wherein the conductive line and the conductive runner cooperate to produce an inductive effect.
2. The method of claim 1 wherein forming the conductive line further comprises:
forming a conductive layer; and
removing regions of the conductive layer to form the conductive line.
3. The method of claim 2 wherein forming the conductive layer further comprise forming an aluminum conductive layer.
4. The method of claim I wherein forming the conductive runner in the trench further comprises depositing copper in the trench.
5. The method of claim 4 wherein depositing copper in the trench further comprises electroplating copper in the trench.
6. The method of claim 1 wherein forming the trench in the dielectric layer further comprises forming the trench in vertical alignment with the conductive line.
7. The method of claim 1 wherein forming the trench in the dielectric layer further comprises forming the trench in vertical alignment with the conductive line.
8. The method of claim 1 further comprising:
forming an opening in the second dielectric layer extending to the conductive pad;
forming a conductive structure in the opening, wherein the conductive structure forms an inductor terminal.
9. The method of claim 8 wherein forming the conductive structure further comprises forming a solder bump.
10. The method of claim 8 wherein forming the conductive structure further comprises forming a bond pad.