Vishay Intertechnology, Inc.

Vishay-siliconix

Harianto Wong

Sik Lui

Haim Goldberger

Jacek Korec

Y Mohammed Kasem

Jack Van Den Heuvel

A method of fabricating a capacitor in a semiconductor substrate. The semiconductor substrate is doped to have a low resistivity. A second electrode, insulated from a first electrode, is formed over a front side surface and connected by a metal-filled via to the back side surface. The via may be omitted and the second electrode may be in electrical contact with the substrate or may be formed on top of the dielectric layer, yielding a pair of series-connected capacitors. ESD protection for the capacitor is provided by a pair of oppositely-directed diodes formed in the substrate connected in parallel with the capacitor. Capacitance is increased while maintaining a low effective series resistance. Electrodes include a plurality of fingers, which are interdigitated with the fingers of other electrode. The capacitor is fabricated in a wafer-scale process with other capacitors, where capacitors are separated from each other by a dicing technique.

Precision high-frequency capacitor formed on semiconductor substrate

A precision high-frequency capacitor includes a dielectric layer formed on the front side surface of a semiconductor substrate and a first electrode on top of the dielectric layer. The semiconductor substrate is heavily doped and therefore has a low resistivity. A second electrode, insulated from the first electrode, is also formed over the front side surface. In one embodiment, the second electrode is connected by a metal-filled via to a layer of conductive material on the back side of the substrate. In alternative embodiments, the via is omitted and the second electrode is either in electrical contact with the substrate or is formed on top of the dielectric layer, yielding a pair of series-connected capacitors. ESD protection for the capacitor can be provided by a pair of oppositely-directed diodes formed in the substrate and connected in parallel with the capacitor. To increase the capacitance of the capacitor while maintaining a low effective series resistance, each of the electrodes may include a plurality of fingers, which are interdigitated with the fingers of the other electrode. The capacitor is preferably fabricated in a wafer-scale process concurrently with numerous other capacitors on the wafer, and the capacitors are then separated from each other by a conventional dicing technique.

Precision high-frequency capacitor on semiconductor substrate

Growing community of inventors

Santa Clara, CA, United States of America

Harianto Wong