Patents by Inventor Sierra HOFF

Sierra HOFF has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10316431
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Grant
    Filed: October 20, 2015
    Date of Patent: June 11, 2019
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 9543393
    Abstract: The present invention discloses a group III nitride wafer such as GaN, AlN, InN and their alloys having one surface visually distinguishable from the other surface. After slicing of the wafer from a bulk crystal of group III nitride with a mechanical method such as multiple wire saw, the wafer is chemically etched so that one surface of the wafer is visually distinguishable from the other surface. The present invention also discloses a method of producing such wafers.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: January 10, 2017
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 9518340
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 13, 2016
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 9452495
    Abstract: The present invention discloses a new tool to slice crystal ingots by using laser beams. Ingot crystals of III-nitride such as GaN are immersed in alkali solutions and irradiated with scanned lines of laser beams to slice wafers out of the ingots. The method is expected to achieve approximately one order of magnitude smaller slicing loss with minimized slicing damage.
    Type: Grant
    Filed: July 6, 2012
    Date of Patent: September 27, 2016
    Assignee: SixPoint Materials, Inc.
    Inventors: Tadao Hashimoto, Sierra Hoff
  • Patent number: 9435051
    Abstract: The present invention discloses a semi-insulating wafer of GaxAlyIn1-x-yN (0?x?1, 0?x+y?1) which is doped with bismuth (Bi). The semi-insulating wafer has the resistivity of 104 ohm-cm or more. Although it is very difficult to obtain a single crystal ingot of group III nitride, the ammonothermal method can grow highly-oriented poly or single crystal ingot of group III nitride having the density of dislocations/grain boundaries less than 105 cm?2. The invention also disclose the method of fabricating the semi-insulating group III nitride bulk crystals and wafers.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: September 6, 2016
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20160130720
    Abstract: The present invention discloses a semi-insulating wafer of GaxAlyIn1-x-yN (0?x?1, 0?x+y?1) which is doped with bismuth (Bi). The semi-insulating wafer has the resistivity of 104 ohm-cm or more. Although it is very difficult to obtain a single crystal ingot of group III nitride, the ammonothermal method can grow highly-oriented poly or single crystal ingot of group III nitride having the density of dislocations/grain boundaries less than 105 cm?2. The invention also disclose the method of fabricating the semi-insulating group III nitride bulk crystals and wafers.
    Type: Application
    Filed: December 28, 2015
    Publication date: May 12, 2016
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20160040318
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Application
    Filed: October 20, 2015
    Publication date: February 11, 2016
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 9255342
    Abstract: The present invention discloses a semi-insulating wafer of GaxAlyIn1-x-yN (0?x?1, 0?x+y?1) which is doped with bismuth (Bi). The semi-insulating wafer has the resistivity of 104 ohm-cm or more. Although it is very difficult to obtain a single crystal ingot of group III nitride, the ammonothermal method can grow highly-oriented poly or single crystal ingot of group III nitride having the density of dislocations/grain boundaries less than 105 cm?2. The invention also disclose the method of fabricating the semi-insulating group III nitride bulk crystals and wafers.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: February 9, 2016
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 9202872
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 1, 2015
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Patent number: 8921231
    Abstract: The present invention discloses a group III nitride wafer such as GaN, AlN, InN and their alloys having one surface visually distinguishable from the other surface. After slicing of the wafer from a bulk crystal of group III nitride with a mechanical method such as multiple wire saw, the wafer is chemically etched so that one surface of the wafer is visually distinguishable from the other surface. The present invention also discloses a method of producing such wafers.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 30, 2014
    Assignees: SixPoint Materials, Inc., Seoul Semiconductor Co., Ltd.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20140087209
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Application
    Filed: March 15, 2013
    Publication date: March 27, 2014
    Applicants: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20140087113
    Abstract: The present invention provides a method of growing an ingot of group III nitride. Group III nitride crystals such as GaN are grown by the ammonothermal method on both sides of a seed to form an ingot and the ingot is sliced into wafers. The wafer including the first-generation seed is sliced thicker than the other wafers so that the wafer including the first-generation seed does not break. The wafer including the first-generation seed crystal can be used as a seed for the next ammonothermal growth.
    Type: Application
    Filed: March 15, 2013
    Publication date: March 27, 2014
    Applicants: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20140061662
    Abstract: The present invention discloses a group III nitride wafer such as GaN, AlN, InN and their alloys having one surface visually distinguishable from the other surface. After slicing of the wafer from a bulk crystal of group III nitride with a mechanical method such as multiple wire saw, the wafer is chemically etched so that one surface of the wafer is visually distinguishable from the other surface. The present invention also discloses a method of producing such wafers.
    Type: Application
    Filed: March 15, 2013
    Publication date: March 6, 2014
    Applicants: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20140065796
    Abstract: The present invention discloses a group III nitride wafer such as GaN, AlN, InN and their alloys having one surface visually distinguishable from the other surface. After slicing of the wafer from a bulk crystal of group III nitride with a mechanical method such as multiple wire saw, the wafer is chemically etched so that one surface of the wafer is visually distinguishable from the other surface. The present invention also discloses a method of producing such wafers.
    Type: Application
    Filed: March 15, 2013
    Publication date: March 6, 2014
    Applicants: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
    Inventors: Tadao Hashimoto, Edward Letts, Sierra Hoff
  • Publication number: 20140054589
    Abstract: The present invention discloses a semi-insulating wafer of GaxAlyIn1-x-yN (0?x?1, 0?x+y?1) which is doped with bismuth (Bi). The semi-insulating wafer has the resistivity of 104 ohm-cm or more. Although it is very difficult to obtain a single crystal ingot of group III nitride, the ammonothermal method can grow highly-oriented poly or single crystal ingot of group III nitride having the density of dislocations/grain boundaries less than 105 cm?2. The invention also disclose the method of fabricating the semi-insulating group III nitride bulk crystals and wafers.
    Type: Application
    Filed: February 28, 2013
    Publication date: February 27, 2014
    Applicants: Seoul Semiconductor Co., Ltd., SixPoint Materials, Inc.
    Inventors: Tadao HASHIMOTO, Edward LETTS, Sierra HOFF