General Electric Company

Fairchild Semiconductor Corporation

Tat-Sing P Chow

Bantval J Baliga

Mario Ghezzo

Richard J Saia

William Andrew Hennessy

Manjin J Kim

Hsueh-Rong Chang

James William Kretchmer

Victor A Temple

Paul Alan McConnelee

Dale M Brown

James F Gibbons

Charles S Korman

Bernard Gorowitz

Eric J Wildi

Patricia A Piacente

Krishna Shenai

Victor Albert Keith Temple

Doping of the P type base region in a MOSFET or an IGBT with a combination of boron and one or more of indium, aluminum and gallium, provides a structure having a lower P type doping level in the channel portion of the structure than in the remainder of the structure without requiring counter doping of the channel. The doping level of the emitter region of an MCT is kept high everywhere except in the channel in order to provide a fast turn-off time for the MCT.

Method to enhance operating characteristics of FET, IGBT, and MCT structures

A semiconductor device includes a semiconductor substrate having an epitaxial layer surface opposite a drain contact surface; a semiconductor layer adjacent to the epitaxial layer surface of the substrate, the semiconductor layer including material of a first conductivity type; a patterned refractory dielectric layer adjacent to the semiconductor layer; a base region of implanted ions in the semiconductor layer, the base region being of a second conductivity type; a source region of implanted ions in the base region, the source region being of the first conductivity type; a gate insulator layer adjacent to at least a portion of the source and base regions of the semiconductor layer; and a gate electrode over a portion of the gate insulator layer, adjacent to and in physical contact with an outer edge of the patterned refractory dielectric layer, and over at least a portion of the base region between the source region and the patterned refractory dielectric layer.

Self-aligned transistor device including a patterned refracting

A method for fabricating a semiconductor device includes patterning a refractory dielectric layer over a semiconductor layer of a first conductivity type; conformally depositing a first spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the first spacer layer to leave a first spacer adjacent to an edge of the patterned refractory dielectric layer; implanting ions of a second conductivity type to form a base region in the semiconductor layer; conformally depositing a second spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the second spacer layer to leave a second spacer adjacent to an edge of the first spacer; implanting ions of the first conductivity type to form a source region in the base region; removing the first and second spacers; applying a gate insulator layer over at least a portion of the semiconductor layer; conformally depositing a gate electrode layer over the gate insulator layer and the semiconductor layer; and patterning the gate electrode layer to form a gate electrode portion adjacent to an edge of the patterned refractory dielectric layer. Preferably the step of conformally depositing the gate electrode layer includes depositing an electrically conductive layer having the same thickness as a combined width of the first and second spacers. In one embodiment the semiconductor layer includes silicon carbide, the patterned refractory dielectric layer includes silicon dioxide, the spacers include silicon nitride, and the gate electrode layer includes polysilicon.

Method of fabricating a self-aligned DMOS transistor device using SiC

A multi-cellular power field effect semiconductor device includes a high conductivity layer of metal or a metal silicide disposed in intimate contact with the source region of the device. This high conductivity layer is self-aligned with respect to the aperture in the gate electrode through which the source region is diffused. The presence of this high conductivity layer allows a substantially smaller contact window to be employed for making contact between the final metallization and the source region. As a consequence, the aperture in the gate electrode and the cell size of the device can both be substantially reduced. The device has substantially improved operating characteristics. A method of producing the device is also described.

Power field effect devices having small cell size and low contact

An IGBT and FET are integrated in a common semiconductor body and share common source/emitter, base and drift regions and an insulated gate electrode. The ON-resistance and turn-off time of this device can be controlled by connecting the drain and collector electrodes to one main terminal for the device with a resistor between either the drain region/drift region interface or the collector junction and the main terminal of the device.

Circuit including a combined insulated gate bipolar transistor/MOSFET

A semiconductor wafer having a substrate with an epitaxial layer thereon includes a semiconductor device electrically isolated from the substrate as well as from any other devices in the wafer by electrical isolation structure comprising semiconductor material. The semiconductor device can accordingly be operated at high voltage with respect to the wafer substrate. The isolation structure in one form of the wafer comprises an N+ high voltage tub included in the wafer and a P+ ground region situated in the expitaxial layer, adjoining the substrate, and horizontally circumscribing the N+ high voltage tub and being spaced therefrom by a minimum layer extent of a portion of the epitaxial layer that is of N conductivity type. The N+ high voltage tub comprises an N+ high voltage region situated in the epitaxial layer and surrounding a device region in which the semiconductor device is at least partially contained and, further, an N+ buried layer underlying the N+ high voltage region and the entirety of the device region.

Semiconductor wafer with an electrically-isolated semiconductor device

A power field effect device has a high voltage blocking junction which intersects the device surface under the gate electrode. That intersection is a closed plane geometric figure whose center is within the body region of the device rather than in the more heavily doped base region of the device. The figure preferably is everywhere convex and has a maximum width of substantially less than the depletion width, at breakdown, of a corresponding parallel plane junction. The device breakdown voltage is higher than the breakdown voltage of a corresponding junction having a cylindrical edge with a straight axis. In a preferred embodiment, the high voltage blocking junction has a plurality of such intersections with the device surface, each situated beneath a segment of the gate electrode. In a bipolar embodiment, the gate electrode may be omitted.

Vertical double diffused metal oxide semiconductor (VDMOS) device

A power field effect device has a gate grid having a plurality of elongate openings therein through which a base region forming a high voltage blocking junction with the underlying body was diffused. The openings have round ends in order to prevent the formation of spherical portions in the high voltage blocking junction. The round ends of adjacent openings are positioned close enough to each other that their diffusion regions merge, thereby raising the device breakdown voltage to that of the cylindrical junction portion along the straight edges of the junction. In an alternative embodiment, the openings do not have round ends and are positioned close enough together that their diffusions merge end to end.

Vertical double diffused metal oxide semiconductor VDMOS device with

An eight mask process for forming a lateral insulated gate semiconductor device is disclosed. The gate structure can be used as a mask to align the third and fifth regions of the device and a third protective layer aligns the fourth and sixth regions of the device.

Minimal mask process for fabricating a lateral insulated gate

Reduction in the forward current gain of an inherent bipolar transistor in an insulated-gate semiconductor device such as an IGT or an IGFET is achieved by implantation of selected ions into the semiconductor material of such device. The ions, which create defects in the implanted region constituting current carrier recombination centers, form a layer with a peak concentration situated in proximity to the emitter-base junction of the inherent bipolar transistor. The layer of ions is of small thickness, whereby the resulting increase in the respective sheet resistances of the emitter and base layers to either side of the emitter-base junction is minimized.

Method of reducing the current gain of an inherent bipolar transistor in

A composite conductive structure which includes an insulating substrate on which is provided a conductor of molybdenum covered by a layer of molybdenum nitride and a method of making the structure are described. The method includes heating the conductor of molybdenum in an atmosphere of ammonia in the range from about 400.degree. C. to 850.degree. C. for a time to cause the atmosphere to react with the conductor to convert a portion of the conductor into molybdenum nitride.

Composite conductive structures and method of making same

A method of reducing lateral field oxidation in the vicinity of the active regions of a silicon substrate in which integrated circuit elements are to be formed. Mesas, the tops of which are the active regions, are formed by ion beam etching of the silicon substrate. The mesas are protected by caps of silicon nitride overlying the top and sides of the mesas during field oxide formation. Subsequently the caps of silicon nitride are removed and the exposed sides of the mesas are oxidized to form a thick layer of silicon dioxide contiguous to the mesas.

Method of making integrated circuits

A method of making a composite conductive structure is described. The structure includes an insulating substrate on which is provided a conductor of a refractory metal substantially nonreactive with silicon dioxide covered by a layer of a silicide of the refractory metal and a layer of silicon dioxide. The method includes depositing a layer of polycrystalline silicon over the conductor and the insulating substrate, reacting the layer of polycrystalline silicon with the conductor to form a refractory metal silicide, removing the unreacted portion of the layer of polycrystalline silicon, and then oxidizing the exposed surface of the refractory metal silicide into a layer of silicon dioxide.

Growing community of inventors

Schenectady, NY, United States of America

Tat-Sing P Chow