Kyma Technologies, Inc.

Edward Preble

Andrew David Hanser

Xueping Xu

N Mark Williams

Lianghong Liu

Denis Tsvetkov

Nathaniel Mark Williams

Terry Lee Clites

Keith Richard Evans

Group III (Al, Ga, In)N single crystals, articles and films useful for producing optoelectronic devices (such as light emitting diodes (LEDs), laser diodes (LDs) and photodetectors) and electronic devices (such as high electron mobility transistors (HEMTs)) composed of III-V nitride compounds, and methods for fabricating such crystals, articles and films.

Group III nitride articles and methods for making same

Group III nitride articles having nucleation layers, transitional layers, and bulk layers

In a method for making a GaN article, an epitaxial nitride layer is deposited on a single-crystal substrate. A 3D nucleation GaN layer is grown on the epitaxial nitride layer by HVPE under a substantially 3D growth mode. A GaN transitional layer is grown on the 3D nucleation layer by HVPE under a condition that changes the growth mode from the substantially 3D growth mode to a substantially 2D growth mode. A bulk GaN layer is grown on the transitional layer by HVPE under the substantially 2D growth mode. A polycrystalline GaN layer is grown on the bulk GaN layer to form a GaN/substrate bi-layer. The GaN/substrate bi-layer may be cooled from the growth temperature to an ambient temperature, wherein GaN material cracks laterally and separates from the substrate, forming a free-standing article.

Single crystal group III nitride articles and method of producing same by HVPE method incorporating a polycrystalline layer for yield enhancement

Method for making group III nitride articles

In a method for making an inclusion-free uniformly semi-insulating GaN crystal, an epitaxial nitride layer is deposited on a substrate. A 3D nucleation GaN layer is grown on the epitaxial nitride layer by HVPE under a substantially 3D growth mode, wherein a surface of the nucleation layer is substantially covered with pits and the aspect ratio of the pits is essentially the same. A GaN transitional layer is grown on the nucleation layer by HVPE under a condition that changes the growth mode from the substantially 3D growth mode to a substantially 2D growth mode. After growing the transitional layer, a surface of the transitional layer is substantially pit-free. A bulk GaN layer is grown on the transitional layer by HVPE. After growing the bulk layer, a surface of the bulk layer is smooth and substantially pit-free. The GaN is doped with a transition metal during at least one of the foregoing GaN growth steps.

Inclusion-free uniform semi-insulating group III nitride substrates and methods for making same

Inclusion-free uniform semi-insulating group III nitride substrate and methods for making same

Non-polar or semi-polar (Al, Ga, In)N substrates are fabricated by re-growth of (Al, Ga, In)N crystal on (Al, Ga, In)N seed crystals, wherein the size of the seed crystal expands or is increased in the lateral and vertical directions, resulting in larger sizes of non-polar and semi-polar substrates useful for optoelectronic and microelectronic devices. One or more non-polar or semi-polar substrates may be sliced from the re-grown crystal. The lateral growth rate may be greater than the vertical growth rate. The seed crystal may be a non-polar seed crystal. The seed crystal may have crystalline edges of equivalent crystallographic orientation.

Non-polar and semi-polar GaN substrates, devices, and methods for making them

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Raleigh, NC, United States of America

Edward Preble