Kabushiki Kaisha Toshiba

Toshiba Techno Center Inc.

Samsung Electronics Co., Ltd.

Bridgelux Incorporated

Toshiba Corporation

Jeff Ramer

Steven D Lester

Ling Zhang

Jun Wu

William E Fenwick

Ghulam Hasnain

Syn-Yem Hu

Steve Ting

Steven Lester

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 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 light emitting device and method for making the same is disclosed. The light-emitting device includes an active layer sandwiched between a p-type semiconductor layer and an n-type semiconductor layer. The active layer emits light when holes from the p-type semiconductor layer combine with electrons from the n-type semiconductor layer therein. The active layer includes a number of sub-layers and has a plurality of pits in which the side surfaces of a plurality of the sub-layers are in contact with the p-type semiconductor material such that holes from the p-type semiconductor material are injected into those sub-layers through the exposed side surfaces without passing through another sub-layer. The pits can be formed by utilizing dislocations in the n-type semiconductor layer and etching the active layer using an etching atmosphere in the same chamber used to deposit the semiconductor layers without removing the partially fabricated device.

LED with improved injection efficiency

A light emitting device comprises a first layer having an n-type Group III-V semiconductor, a second layer adjacent to the first layer, the second layer comprising an active material that generates light upon the recombination of electrons and holes. The active material in some cases has one or more V-pits at a density between about 1 V-pit/&#x3bc;mand 30 V-pits/&#x3bc;m. The light emitting device includes a third layer adjacent to the second layer, the third layer comprising a p-type Group III-V semiconductor.

Light emitting regions for use with light emitting devices

A light emitting device and method for making the same is disclosed. The light-emitting device includes an active layer sandwiched between a p-type semiconductor layer and an n-type semiconductor layer. The active layer emits lights when holes from the p-type semiconductor layer combine with electrons from the n-type semiconductor layer therein. The active layer includes a number of sub-layers and has a plurality of pits in which the side surfaces of a plurality of the sub-layers are in contact with the p-type semiconductor material such that holes from the p-type semiconductor material are injected into those sub-layers through the exposed side surfaces without passing through another sub-layer. The pits can be formed by utilizing dislocations in the n-type semiconductor layer and etching the active layer using an etching atmosphere in the same chamber used to deposit the semiconductor layers without removing the partially fabricated device.

A light source and method for making the same are disclosed. The light source includes a substrate and a light emitting structure that is deposited on the substrate. A barrier divides the light emitting structure into first and second segments that are electrically isolated from one another. A serial connection electrode connects the first segment in series with the second segment. A first blocking diode between the light emitting structure and the substrate prevents current from flowing between the light emitting structure and the substrate when the light emitting structure is emitting light. The barrier extends through the light emitting structure into the first blocking diode.

Growing community of inventors

Sunnyvale, CA, United States of America

Jeff Ramer