Michael G Spencer

US Patent:

6547876, Apr 15, 2003

Filed:

Feb 7, 2001

Appl. No.:

09/778869

Inventors:

Ian Ferguson - Princeton NJ
Alexander Gurary - Bridgewater NJ
Michael Spencer - Washington DC

Assignee:

Emcore Corporation - Somerset NJ

International Classification:

C30B 2512

US Classification:

117 88, 117101, 117200, 118715 R, 118729, 118730

Abstract:

The invention describes an apparatus for chemical vapor deposition on substrates, a related method of deposition of epitaxial layers on the wafers and an assemblage for use therewith. In the apparatus of the invention, the wafers are placed directly on the surface of a heating filament. The apparatus of the invention may include a reaction chamber, a rotatable spindle, a plurality of rotatable electrodes mounted on the spindle for rotation together with the spindle and a heating filament in electrical contact with the rotatable electrodes. The heating filament may be rotated by rotating the rotatable electrodes, and heated by providing electric current to the electrodes. In one embodiment of the invention, heating filament may be detached from the rotatable electrodes to load or unload the wafers. Preferably, the heating filament is transported between a deposition position and a loading position. Alternatively, the heating filament is permanently mounted on the electrodes.

US Patent:

7381391, Jun 3, 2008

Filed:

Jan 5, 2007

Appl. No.:

11/650569

Inventors:

Michael G. Spencer - Ithaca NY, US
Francis J. DiSalvo - Ithaca NY, US
Huaqiang Wu - Mountain View CA, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

C01B 21/064
C01B 21/06
C01B 21/072

US Classification:

423290, 423409, 423412

Abstract:

The present invention provides compositions and a novel high-yielding process for preparing high purity Group III nitrides. The process involves heating a Group III metal and a catalytic amount of a metal wetting agent in the presence of a nitrogen source. Group III metals can be stoichiometrically converted into high purity Group III nitride powders in a short period of time. The process can provide multi-gram quantities of high purity Group III nitrides in relatively short reaction times. Detailed characterizations of GaN powder were preformed and are reported herein, including morphology and structure by SEM and XRD, optical properties by cathodoluminescence (CL), and Raman spectra to determine the quality of the GaN particles. The purity of GaN powder was found to be greater than 99. 9% pure, as analyzed by Glow Discharge Mass Spectrometry (GDMS).

US Patent:

7569206, Aug 4, 2009

Filed:

Apr 1, 2008

Appl. No.:

12/060749

Inventors:

Michael G. Spencer - Ithaca NY, US
Francis J. DiSalvo - Ithaca NY, US
Huaqiang Wu - Mountain View CA, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

C01B 21/06

US Classification:

423490

Abstract:

The present invention provides compositions and a novel high-yielding process for preparing high purity Group III nitrides. The process involves heating a Group III metal and a catalytic amount of a metal wetting agent in the presence of a nitrogen source. Group III metals can be stoichiometrically converted into high purity Group III nitride powders in a short period of time. The process can provide multi-gram quantities of high purity Group III nitrides in relatively short reaction times. Detailed characterizations of GaN powder were performed and are reported herein, including morphology and structure by SEM and XRD, optical properties by cathodoluminescence (CL), and Raman spectra to determine the quality of the GaN particles. The purity of GaN powder was found to be greater than 99. 9% pure, as analyzed by Glow Discharge Mass Spectrometry (GDMS).

US Patent:

7663288, Feb 16, 2010

Filed:

Aug 24, 2006

Appl. No.:

11/509323

Inventors:

M V S Chandrashekhar - Ithaca NY, US
Christopher Ian Thomas - Ithaca NY, US
Michael G. Spencer - Ithaca NY, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

G21H 1/00

US Classification:

310303

Abstract:

High aspect ratio micromachined structures in semiconductors are used to improve power density in Betavoltaic cells by providing large surface areas in a small volume. A radioactive beta-emitting material may be placed within gaps between the structures to provide fuel for a cell. The pillars may be formed of SiC. In one embodiment, SiC pillars are formed of n-type SiC. P type dopant, such as boron is obtained by annealing a borosilicate glass boron source formed on the SiC. The glass is then removed. In further embodiments, a dopant may be implanted, coated by glass, and then annealed. The doping results in shallow planar junctions in SiC.

US Patent:

7772288, Aug 10, 2010

Filed:

Jun 1, 2007

Appl. No.:

11/809879

Inventors:

Huaqiang Wu - Mountain View CA, US
Michael G. Spencer - Ithaca NY, US
Emmanuel Giannelis - Ithaca NY, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

B01F 3/12
C09K 11/02
C01B 21/06
H01L 21/20

US Classification:

516 33, 516 88, 516 93, 2523014 R, 25230136

Abstract:

The invention provides a composition that is a dispersion made from a Group III nitride, a solvent system, and a dispersant. The dispersion can be used to prepare Group III nitride thin films on a wide range of substrates, for example, glass, silicon, silicon dioxide, silicon nitride, silicon carbide, aluminum nitride, sapphire, and organic polymers. The particle size of the Group III nitride used for producing the thin films can be controlled by adjusting centrifugation of the dispersion and selecting a desired layer of supernatant. The dispersant can be removed from the thin films by calcination. The Group III nitride can contain a dopant. Doped Group III nitride thin films can emit visible light upon irradiation. Green, red, and yellow light emissions result from irradiating erbium-, europium-, and cerium-doped gallium nitride, respectively.

US Patent:

7867335, Jan 11, 2011

Filed:

Oct 2, 2006

Appl. No.:

11/541919

Inventors:

Michael G. Spencer - Ithaca NY, US
Phani Konkapaka - Boise ID, US
Huaqiang Wu - Sunnyvale CA, US
Yuri Makarov - Midlothian VA, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

C30B 21/02

US Classification:

117 84, 117 89, 117 94, 117104, 117105

Abstract:

GaN is grown by creating a Ga vapor from a powder, and using an inert purge gas from a source to transport the vapor to a growth site where the GaN growth takes place. In one embodiment, the inert gas is N, and the powder source is GaN powder that is loaded into source chambers. The GaN powder is congruently evaporated into Ga and Nvapors at temperatures between approximately 1000 and 1200 C. The formation of Ga liquid in the powder is suppressed by the purging of an inert gas through the powder. The poser may also be isolated from a nitride containing gas provided at the growth cite. In one embodiment, the inert gas is flowed through the powder.

US Patent:

7901508, Mar 8, 2011

Filed:

Jan 24, 2007

Appl. No.:

11/626387

Inventors:

Yuri Makarov - Richmond VA, US
Michael Spencer - Ithaca NY, US

Assignee:

Widetronix, Inc. - DE

International Classification:

C30B 21/02

US Classification:

117200, 117900, 118715

Abstract:

An approach for the growth of high-quality epitaxial silicon carbide (SiC) films and boules, using the Chemical Vapor Deposition (CVD) technique is described here. The method comprises modifications in the design of the typical cold-wall CVD reactors, providing a better temperature uniformity in the reactor bulk and a low temperature gradient in the vicinity of the substrate, and an approach to increase the silicon carbide growth rate and to improve the quality of the growing layers, using halogenated carbon-containing precursors (carbon tetrachloride CClor halogenated hydrocarbons, CHCl, CHCl, CHCl, etc. ), or introducing other chlorine-containing species in the gas phase in the growth chamber. The etching effect, proper ranges, and high temperature growth are also examined.

US Patent:

7939986, May 10, 2011

Filed:

Dec 14, 2009

Appl. No.:

12/637463

Inventors:

MVS Chandrashekhar - Ithaca NY, US
Christopher Ian Thomas - Ithaca NY, US
Michael G. Spencer - Ithaca NY, US

Assignee:

Cornell Research Foundation, Inc. - Ithaca NY

International Classification:

G21H 1/00

US Classification:

310303

Abstract:

High aspect ratio micromachined structures in semiconductors are used to improve power density in Betavoltaic cells by providing large surface areas in a small volume. A radioactive beta-emitting material may be placed within gaps between the structures to provide fuel for a cell. The pillars may be formed of SiC. In one embodiment, SiC pillars are formed of n-type SiC. P type dopant, such as boron is obtained by annealing a borosilicate glass boron source formed on the SiC. The glass is then removed. In further embodiments, a dopant may be implanted, coated by glass, and then annealed. The doping results in shallow planar junctions in SiC.

Address:

5731 Jonquil Ave, Baltimore, MD 21215

VIN:

1HGCM55377A062700

Make:

HONDA

Model:

ACCORD

Year:

2007

Address:

PO Box 260, Philadelphia, PA 19105

VIN:

1FTPW14V67FA20169

Make:

FORD

Model:

F-150

Year:

2007