Nitronex Corporation

North Carolina State University

International Rectifier Corporation

Infineon Technologies Americas Corp.

Pradeep Rajagopal

Edwin Lanier Piner

John Claassen Roberts

Kevin J Linthicum

Allen W Hanson

Thomas Gehrke

Robert F Davis

Jerry Wayne Johnson

Robert Joseph Therrien

Darren B Thomson

Walter H Nagy

James W Cook, Jr

Sameer Singhal

Ricardo M Borges

Eric Porter Carlson

Jeffrey D Brown

Andrei Vescan

Apurva D Chaudhari

Chul Hi Park

Craig E Strautin

Alan W Hanson

Semiconductor materials including a gallium nitride material region and methods associated with such structures are provided. The semiconductor structures include a strain-absorbing layer formed within the structure. The strain-absorbing layer may be formed between the substrate (e.g., a silicon substrate) and an overlying layer. It may be preferable for the strain-absorbing layer to be very thin, have an amorphous structure and be formed of a silicon nitride-based material. The strain-absorbing layer may reduce the number of misfit dislocations formed in the overlying layer (e.g., a nitride-based material layer) which limits formation of other types of defects in other overlying layers (e.g., gallium nitride material region), amongst other advantages. Thus, the presence of the strain-absorbing layer may improve the quality of the gallium nitride material region which can lead to improved device performance.

Gallium nitride materials and methods associated with the same

Semiconductor structures including one, or more, III-nitride material regions (e.g., gallium nitride material region) and methods associated with such structures are provided. The III-nitride material region(s) advantageously have a low dislocation density and, in particular, a low screw dislocation density. In some embodiments, the presence of screw dislocations in the III-nitride material region(s) may be essentially eliminated. The presence of a strain-absorbing layer underlying the III-nitride material region(s) and/or processing conditions can contribute to achieving the low screw dislocation densities. In some embodiments, the III-nitride material region(s) having low dislocation densities include a gallium nitride material region which functions as the active region of the device. The low screw dislocation densities of the active device region (e.g., gallium nitride material region) can lead to improved properties (e.g., electrical and optical) by increasing electron transport, limiting non-radiative recombination, and increasing compositional/growth uniformity, amongst other effects.

III-nitride materials including low dislocation densities and methods associated with the same

Gallium nitride material transistors and methods associated with the same are provided. The transistors may be used in power applications by amplifying an input signal to produce an output signal having increased power. The transistors may be designed to transmit the majority of the output signal within a specific transmission channel (defined in terms of frequency), while minimizing transmission in adjacent channels. This ability gives the transistors excellent linearity which results in high signal quality and limits errors in transmitted data. The transistors may be designed to achieve low ACPR values (a measure of excellent linearity), while still operating at high drain efficiencies and/or high output powers. Such properties enable the transistors to be used in RF power applications including third generation (3G) power applications based on W-CDMA modulation.

Gallium nitride material transistors and methods associated with the same

Gallium nitride material-based semiconductor structures are provided. In some embodiments, the structures include a composite substrate over which a gallium nitride material region is formed. The gallium nitride material structures may include additional features, such as strain-absorbing layers and/or transition layers, which also promote favorable stress conditions. The reduction in stresses may reduce defect formation and cracking in the gallium nitride material region, as well as reducing warpage of the overall structure. The gallium nitride material-based semiconductor structures may be used in a variety of applications such as transistors (e.g. FETs) Schottky diodes, light emitting diodes, laser diodes, SAW devices, and sensors, amongst others devices.

Gallium nitride material structures including substrates and methods associated with the same

Gallium nitride material devices and methods associated with the devices are described. The devices may be designed to provide enhanced thermal conduction and reduced thermal resistance. The increased thermal conduction through and out of the gallium nitride devices enhances operability of the devices, including providing excellent RF operation, reliability, and lifetime.

Gallium nitride material devices and thermal designs thereof

An underlying gallium nitride layer on a silicon carbide substrate is masked with a mask that includes an array of openings therein, and the underlying gallium nitride layer is etched through the array of openings to define posts in the underlying gallium nitride layer and trenches therebetween. The posts each include a sidewall and a top having the mask thereon. The sidewalls of the posts are laterally grown into the trenches to thereby form a gallium nitride semiconductor layer. During this lateral growth, the mask prevents nucleation and vertical growth from the tops of the posts. Accordingly, growth proceeds laterally into the trenches, suspended from the sidewalls of the posts. The sidewalls of the posts may be laterally grown into the trenches until the laterally grown sidewalls coalesce in the trenches to thereby form a gallium nitride semiconductor layer. The lateral growth from the sidewalls of the posts may be continued so that the gallium nitride layer grows vertically through the openings in the mask and laterally overgrows onto the mask on the tops of the posts, to thereby form a gallium nitride semiconductor layer. The lateral overgrowth can be continued until the grown sidewalls coalesce on the mask to thereby form a continuous gallium nitride semiconductor layer. Microelectronic devices may be formed in the continuous gallium nitride semiconductor layer.

Pendeoepitaxial gallium nitride semiconductor layers on silicon carbide substrates

III-nitride material structures including silicon substrates, as well as methods associated with the same, are described. Parasitic losses in the structures may be significantly reduced which is reflected in performance improvements. Devices (such as RF devices) formed of structures of the invention may have higher output power, power gain and efficiency, amongst other advantages.

III-nitride material structures including silicon substrates

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Raleigh, NC, United States of America

Pradeep Rajagopal