Toshiba Corporation

Samsung Electronics Co., Ltd.

Kabushiki Kaisha Toshiba

Bridelux, Inc.

William E Fenwick

Jeff Ramer

Long Yang

Zhen Chen

Steve Lester

Dong Lee

A silicon wafer used in manufacturing crystalline GaN for light emitting diodes (LEDs) includes a silicon substrate, a buffer layer of aluminum nitride (AlN) and an upper layer of GaN. The silicon wafer has a diameter of at least 200 millimeters and an Si(111)1&#xd7;1 surface. The AlN buffer layer overlies the Si(111) surface. The GaN upper layer is disposed above the buffer layer. Across the entire wafer substantially no aluminum atoms of the AlN are present in a bottom most plane of atoms of the AlN, and across the entire wafer substantially only nitrogen atoms of the AlN are present in the bottom most plane of atoms of the AlN. A method of making the AlN buffer layer includes preflowing a first amount of ammonia equaling less than 0.01% by volume of hydrogen flowing through a chamber before flowing trimethylaluminum and then a subsequent amount of ammonia through the chamber.

Nucleation of aluminum nitride on a silicon substrate using an ammonia preflow

A high electron mobility transistor (HEMT) device with a highly resistive layer co-doped with carbon (C) and a donor-type impurity and a method for making the HEMT device is disclosed. In one embodiment, the HEMT device includes a substrate, the highly resistive layer co-doped with C and the donor-type impurity formed above the substrate, a channel layer formed above the highly resistive layer, and a barrier layer formed above the channel layer. In one embodiment, the highly resistive layer comprises gallium nitride (GaN). In one embodiment, the donor-type impurity is silicon (Si). In another embodiment, the donor-type impurity is oxygen (O).

High electron mobility transistor (HEMT)

A method of making an aluminum nitride (AlN) buffer layer over a silicon wafer for a light emitting diode (LED) includes preflowing a first amount of ammonia that is sufficient to deposit nitrogen atoms on the surface of a silicon wafer without forming SiNx, before flowing trimethylaluminum and then a subsequent amount of ammonia through the chamber.

A silicon wafer used in manufacturing GaN for LEDs includes a silicon substrate, a buffer layer of boron aluminum nitride (BAlN) and an upper layer of GaN, for which 0.35&#x2266;x&#x2266;0.45. The BAlN forms a wurtzite-type crystal with a cell unit length about two-thirds of a silicon cell unit length on a Si(111) surface. The C-plane of the BAlN crystal has approximately one atom of boron for each two atoms of aluminum. Across the entire wafer substantially only nitrogen atoms of BAlN form bonds to the Si(111) surface, and substantially no aluminum or boron atoms of the BAlN are present in a bottom-most plane of atoms of the BAlN. A method of making the BAlN buffer layer includes preflowing a first amount of ammonia equaling less than 0.01% by volume of hydrogen flowing through a chamber before flowing trimethylaluminum and triethylboron and then a subsequent amount of ammonia through the chamber.

Boron-containing buffer layer for growing gallium nitride on silicon

A laterally contacted blue LED device involves a PAN structure disposed over an insulating substrate. The substrate may be a sapphire substrate that has a template layer of GaN grown on it. The PAN structure includes an n-type GaN layer, a light-emitting active layer involving indium, and a p-type GaN layer. The n-type GaN layer has a thickness of at least 500 nm. A Low Resistance Layer (LRL) is disposed between the substrate and the PAN structure such that the LRL is in contact with the bottom of the n-layer. In one example, the LRL is an AlGaN/GaN superlattice structure whose sheet resistance is lower than the sheet resistance of the n-type GnA layer. The LRL reduces current crowding by conducting current laterally under the n-type GaN layer. The LRL reduces defect density by preventing dislocation threads in the underlying GaN template from extending up into the PAN structure.

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Livermore, CA, United States of America

William E Fenwick