Motorola Corporation

E S Ramakrishnan

Wei-Yean Howng

Kenneth David Cornett

Gary H Shapiro

Douglas H Weisman

Wang-Chang A Gu

Adam D Moya

Robert A Burr

Raymond M Caldwell

An integrable circuit inductor (220) is formed from a patterned conductive material (110) that has a major portion completely encapsulated by a material (221, 223) that is substantially electrically non-conductive, and that has a magnetic response at the operating frequency of the inductor (220). Preferably, an amorphous ferrite material is used for encapsulation, which provides a closed magnetic flux path for the inductor (220) when processing a signal at its operating frequency.

Integrable using amorphous magnetic material circuit inductor

High dielectric constant capacitors and/or inductors are formed on a substrate by depositing an amorphous layer (10) of a metal oxide on the substrate (12). A pattern is formed in the metal oxide by wet or dry etching to remove portions (17) of the amorphous material so that only portions (18) of the substrate remain covered. This pattern subsequently becomes the dielectric portion of the capacitor or the inductor. The patterned amorphous layer of metal oxide is then heated under conditions sufficient to convert it from amorphous to crystalline (16), thus increasing the dielectric constant.

Method of forming a capacitor or an inductor on a substrate

An integrated inductor-capacitor (L-C) structure can be formed on a semiconducting substrate (10) by depositing a metal layer in a pattern that contains an inductor coil (14) and a capacitor bottom electrode (12). A CuFe.sub.2 O.sub.4 film (16) is then deposited on the substrate and over the metal pattern to form the dielectric portion of the L-C structure. A via (17) created in the CuFe.sub.2 O.sub.4 film exposes a portion of the inductor coil. Another metal layer (18) is then deposited over the CuFe.sub.2 O.sub.4 film and in the via, such that this metal layer is electrically connected to the inductor coil through the via. A pattern is also made in the second metal layer to form a top electrode (19) for the capacitor, over the corresponding capacitor bottom electrode, and to form a circuit interconnect to the inductor coil through the via.

Integrated inductor and capacitor on a substrate and method for

A radio frequency (RF) choke inductor (102, 500, 600) includes a magnetic core (502, 602) which substantially dissipates RF and microwave signals. The magnetic core (502, 602) is sufficiently lossy to provide a substantially resistive impedance at RF and microwave frequencies. The magnetic core is formed by providing a homogeneous ferrite composition characterized by a mixture of ferrous ions and ferric ions (404), and then sintering the homogeneous ferrite composition in an inert gas atmosphere (412) to provide a rapid electron exchange reaction. A conductive wire is then wound about the magnetic core (414) to complete the choke inductor.

RF choke with a low Q core formed by sintering ferrous and ferric oxides

A semiconductor device (10), comprising a semiconductor substrate (12) having a layer of semiconductor material (14) deposited, coated or grown epitaxially as a single crystal or polysilicon on the surface of the substrate. The layer of material is also a semiconductor material, having a higher resistivity than the substrate it is deposited on. A dielectric layer (16) of a metal oxide is formed on the high resistivity layer (14), which is then covered with an amorphous layer (18) of a metal oxide dielectric. Zirconium titanate may be used as a metal oxide dielectric layer. A metal electrode (20) is formed on the amorphous layer (18) to form a Metal Insulator Semiconductor device. In an alternative configuration, the amorphous layer (18) may instead be placed between the high resistivity layer (14) and the dielectric layer (16), or a second amorphous layer (22) may be added between the high resistivity layer and the dielectric layer. When the device is electrically energized, a depletion region is formed in the high resistivity layer, creating a voltage variable capacitor.

Voltage variable capacitor having amorphous dielectric film

A voltage variable capacitor (10) has as the base substrate a silicon wafer with a layer of high resistivity semiconductor material on top of the substrate. An insulating layer (16) of a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductors (12), such as zirconium titanate, is formed on top of the high resistivity layer, and a metal electrode (18) is formed on the insulating layer (16). When the electrode is energized, a depletion layer (20) is formed in the high resistivity layer. By varying the voltage applied to the electrode, the capacitance of the device is altered.

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Coral Springs, FL, United States of America

E S Ramakrishnan