Siddha Pimputkar

US Patent:

8641823, Feb 4, 2014

Filed:

Nov 4, 2009

Appl. No.:

13/128083

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

C30B 7/10
C30B 29/40
B01D 9/00

US Classification:

117224, 4222451, 422254, 428141, 428697, 2525214, 2525215, 2525216, 252 6255

Abstract:

Reactor designs for use in ammonothermal growth of group-III nitride crystals. Internal heating is used to enhance and/or engineer fluid motion, gas mixing, and the ability to create solubility gradients within a vessel used for the ammonothermal growth of group-III nitride crystals. Novel baffle designs are used for control and improvement of continuous fluid motion within a vessel used for the ammonothermal growth of group-III nitride crystals.

US Patent:

20100111808, May 6, 2010

Filed:

Nov 4, 2009

Appl. No.:

12/612477

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
Makoto Saito - Tsukuba, JP
Steven P. DenBaars - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C30B 25/00
C01B 21/06

US Classification:

423409, 117106, 117 84

Abstract:

The present invention provides a method for growing group III-nitride crystals wherein the group III-nitride crystal growth occurs on an etched seed crystal. The etched seed is fabricated prior to growth using a temperature profile which produces a high solubility of the group III-nitride material in a seed crystals zone as compared to a source materials zone. The measured X-ray diffraction of the obtained crystals have significantly narrower Full Width at Half Maximum values as compared to crystals grown without etch back of the seed crystal surfaces prior to growth.

US Patent:

20110203514, Aug 25, 2011

Filed:

Nov 4, 2009

Appl. No.:

13/128088

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C30B 19/10

US Classification:

117 64, 117206

Abstract:

Reactor designs for use in ammonothermal growth of group-III nitride crystals envision a different relative placement of source materials and seed crystals with respect to each other, and with respect to the vessel containing a solvent. This placement results in a difference in fluid dynamical flow patterns within the vessel.

US Patent:

20110209659, Sep 1, 2011

Filed:

Nov 4, 2009

Appl. No.:

13/128105

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C30B 19/10

US Classification:

117 56, 117206

Abstract:

A method for controlling the relative and absolute growth rates of all possible crystallographic planes of a group-III nitride crystal during ammonothermal growth. The growth rates of the various exposed crystallographic planes of the group-III nitride crystal are controlled by modifying the environment and/or conditions within the reactor vessel, which may be subdivided into a plurality of separate zones, wherein each of the zones has their own environment and conditions. The environment includes the amount of atoms, compounds and/or chemical complexes within each of the zones, along with their relative ratios and the relative motion of the atoms, compounds and/or chemical complexes within each of the zones and among the zones. The conditions include the thermodynamic properties each of the zones possess, such as temperatures, pressures and/or densities.

US Patent:

20110212013, Sep 1, 2011

Filed:

Nov 4, 2009

Appl. No.:

13/128098

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C01B 21/06
C01B 21/072
C30B 19/08

US Classification:

423412, 423406, 423409, 117 56, 117 65

Abstract:

A method for adding hydrogen-containing and/or nitrogen-containing compounds to a nitrogen-containing solvent used during ammonothermal growth of group-Ill nitride crystals to offset decomposition products formed from the nitrogen-containing solvent, in order to shift the balance between the reactants, i.e. the nitrogen-containing solvent and the decomposition products, towards the reactant side.

US Patent:

20110223092, Sep 15, 2011

Filed:

Nov 4, 2009

Appl. No.:

13/128092

Inventors:

Siddha Pimputkar - Goleta CA, US
Derrick S. Kamber - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C30B 7/00
C01B 21/06
B01D 9/00

US Classification:

423409, 117 68, 117206, 4222451

Abstract:

Boron-containing compounds, gasses and fluids are used during ammonothermal growth of group-Ill nitride crystals. Boron-containing compounds are used as impurity getters during the ammonothermal growth of group-Ill nitride crystals. In addition, a boron-containing gas and/or supercritical fluid is used for enhanced solubility of group-Ill nitride into said fluid.

US Patent:

20110300051, Dec 8, 2011

Filed:

Nov 4, 2009

Appl. No.:

13/128079

Inventors:

Derrick S. Kamber - Goleta CA, US
Siddha Pimputkar - Goleta CA, US
Makoto Saito - Ibaraki, JP
Steven P. Denbaars - Gotela CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

C01B 21/06
C30B 7/10

US Classification:

423409, 117 70, 117 64

Abstract:

A method to improve the crystal purity of a group-I11 nitride crystal grown in an ammonothermal growth system by removing any undesired material (i.e., impurities) from within the system prior to, in-between, or after the growth steps for the group-I11 nitride crystal. Impurities are removed from the ammonothermal growth system by first bringing the impurities into solution and then removing part or all of the solution from the growth system. The result is a high purity group-I11 nitride crystal grown in the ammonothermal growth system.

US Patent:

20120063987, Mar 15, 2012

Filed:

Mar 15, 2011

Appl. No.:

13/048179

Inventors:

Siddha Pimputkar - Goleta CA, US
James S. Speck - Goleta CA, US
Shuji Nakamura - Santa Barbara CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

C01B 21/06
C30B 7/10

US Classification:

423409, 117 71, 117224, 423406

Abstract:

A method for ammonothermally growing group-III nitride crystals using an initially off-oriented non-polar and/or semi-polar growth surface on a group-III nitride seed crystal. Group-III-containing source materials and group-III nitride seed crystals are placed into a vessel, wherein the seed crystals have one or more non-polar or semi-polar growth surfaces. Group-III nitride crystals are ammonothermally grown by filling the vessel with a nitrogen-containing solvent for dissolving the source materials and transporting a fluid comprised of the solvent with the dissolved source materials to the seed crystals for growth of the group-III nitride crystals on the seed crystals. The growth surfaces are initially off-oriented growth surfaces, wherein the growth surfaces are off-oriented m-plane or highly vicinal m-plane growth surfaces. The growth surfaces of the seed crystals may be created by cutting group-III nitride crystals at a desired angle with respect to an m-plane.