A new system for sodium flux growth of bulk GaN: Part I : System development

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A new system for sodium flux growth of bulk GaN : Part I : System development. / Von Dollen, Paul; Pimputkar, Siddha; Alreesh, Mohammed Abo; Albrithen, Hamad; Suihkonen, Sami; Nakamura, Shuji; Speck, James S.

In: Journal of Crystal Growth, Vol. 456, 15.12.2016, p. 58-66.

Research output: Contribution to journalArticleScientificpeer-review

Harvard

Von Dollen, P, Pimputkar, S, Alreesh, MA, Albrithen, H, Suihkonen, S, Nakamura, S & Speck, JS 2016, 'A new system for sodium flux growth of bulk GaN: Part I : System development' Journal of Crystal Growth, vol. 456, pp. 58-66. https://doi.org/10.1016/j.jcrysgro.2016.07.044

APA

Von Dollen, P., Pimputkar, S., Alreesh, M. A., Albrithen, H., Suihkonen, S., Nakamura, S., & Speck, J. S. (2016). A new system for sodium flux growth of bulk GaN: Part I : System development. Journal of Crystal Growth, 456, 58-66. https://doi.org/10.1016/j.jcrysgro.2016.07.044

Vancouver

Author

Von Dollen, Paul ; Pimputkar, Siddha ; Alreesh, Mohammed Abo ; Albrithen, Hamad ; Suihkonen, Sami ; Nakamura, Shuji ; Speck, James S. / A new system for sodium flux growth of bulk GaN : Part I : System development. In: Journal of Crystal Growth. 2016 ; Vol. 456. pp. 58-66.

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@article{e01021508bd8486c9f07477c73aba49d,
title = "A new system for sodium flux growth of bulk GaN: Part I : System development",
abstract = "Though several methods exist to produce bulk crystals of gallium nitride (GaN), none have been commercialized on a large scale. The sodium flux method, which involves precipitation of GaN from a sodium-gallium melt supersaturated with nitrogen, offers potentially lower cost production due to relatively mild process conditions while maintaining high crystal quality. We successfully developed a novel apparatus for conducting crystal growth of bulk GaN using the sodium flux method which has advantages with respect to prior reports. A key task was to prevent sodium loss or migration from the growth environment while permitting N2 to access the growing crystal. We accomplished this by implementing a reflux condensing stem along with a reusable capsule containing a hermetic seal. The reflux condensing stem also enabled direct monitoring of the melt temperature, which has not been previously reported for the sodium flux method. Furthermore, we identified and utilized molybdenum and the molybdenum alloy TZM as a material capable of directly containing the corrosive sodium-gallium melt. This allowed implementation of a crucible-free system, which may improve process control and potentially lower crystal impurity levels. Nucleation and growth of parasitic GaN ({"}PolyGaN{"}) on non-seed surfaces occurred in early designs. However, the addition of carbon in later designs suppressed PolyGaN formation and allowed growth of single crystal GaN. Growth rates for the (0001) Ga face (+c-plane) were up to 14μm/h while X-ray omega rocking (ω-XRC) curve full width half-max values were 731″ for crystals grown using a later system design. Oxygen levels were high, >1019 atoms/cm3, possibly due to reactor cleaning and handling procedures.",
keywords = "A1. Na flux method, A1. Reactor Design, A2. Growth from high temperature solutions, A2. Sodium flux growth, B1. Bulk GaN, B1. III-Nitrides, B1. Nitrides",
author = "{Von Dollen}, Paul and Siddha Pimputkar and Alreesh, {Mohammed Abo} and Hamad Albrithen and Sami Suihkonen and Shuji Nakamura and Speck, {James S.}",
year = "2016",
month = "12",
day = "15",
doi = "10.1016/j.jcrysgro.2016.07.044",
language = "English",
volume = "456",
pages = "58--66",
journal = "Journal of Crystal Growth",
issn = "0022-0248",
publisher = "Elsevier",

}

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TY - JOUR

T1 - A new system for sodium flux growth of bulk GaN

T2 - Part I : System development

AU - Von Dollen, Paul

AU - Pimputkar, Siddha

AU - Alreesh, Mohammed Abo

AU - Albrithen, Hamad

AU - Suihkonen, Sami

AU - Nakamura, Shuji

AU - Speck, James S.

PY - 2016/12/15

Y1 - 2016/12/15

N2 - Though several methods exist to produce bulk crystals of gallium nitride (GaN), none have been commercialized on a large scale. The sodium flux method, which involves precipitation of GaN from a sodium-gallium melt supersaturated with nitrogen, offers potentially lower cost production due to relatively mild process conditions while maintaining high crystal quality. We successfully developed a novel apparatus for conducting crystal growth of bulk GaN using the sodium flux method which has advantages with respect to prior reports. A key task was to prevent sodium loss or migration from the growth environment while permitting N2 to access the growing crystal. We accomplished this by implementing a reflux condensing stem along with a reusable capsule containing a hermetic seal. The reflux condensing stem also enabled direct monitoring of the melt temperature, which has not been previously reported for the sodium flux method. Furthermore, we identified and utilized molybdenum and the molybdenum alloy TZM as a material capable of directly containing the corrosive sodium-gallium melt. This allowed implementation of a crucible-free system, which may improve process control and potentially lower crystal impurity levels. Nucleation and growth of parasitic GaN ("PolyGaN") on non-seed surfaces occurred in early designs. However, the addition of carbon in later designs suppressed PolyGaN formation and allowed growth of single crystal GaN. Growth rates for the (0001) Ga face (+c-plane) were up to 14μm/h while X-ray omega rocking (ω-XRC) curve full width half-max values were 731″ for crystals grown using a later system design. Oxygen levels were high, >1019 atoms/cm3, possibly due to reactor cleaning and handling procedures.

AB - Though several methods exist to produce bulk crystals of gallium nitride (GaN), none have been commercialized on a large scale. The sodium flux method, which involves precipitation of GaN from a sodium-gallium melt supersaturated with nitrogen, offers potentially lower cost production due to relatively mild process conditions while maintaining high crystal quality. We successfully developed a novel apparatus for conducting crystal growth of bulk GaN using the sodium flux method which has advantages with respect to prior reports. A key task was to prevent sodium loss or migration from the growth environment while permitting N2 to access the growing crystal. We accomplished this by implementing a reflux condensing stem along with a reusable capsule containing a hermetic seal. The reflux condensing stem also enabled direct monitoring of the melt temperature, which has not been previously reported for the sodium flux method. Furthermore, we identified and utilized molybdenum and the molybdenum alloy TZM as a material capable of directly containing the corrosive sodium-gallium melt. This allowed implementation of a crucible-free system, which may improve process control and potentially lower crystal impurity levels. Nucleation and growth of parasitic GaN ("PolyGaN") on non-seed surfaces occurred in early designs. However, the addition of carbon in later designs suppressed PolyGaN formation and allowed growth of single crystal GaN. Growth rates for the (0001) Ga face (+c-plane) were up to 14μm/h while X-ray omega rocking (ω-XRC) curve full width half-max values were 731″ for crystals grown using a later system design. Oxygen levels were high, >1019 atoms/cm3, possibly due to reactor cleaning and handling procedures.

KW - A1. Na flux method

KW - A1. Reactor Design

KW - A2. Growth from high temperature solutions

KW - A2. Sodium flux growth

KW - B1. Bulk GaN

KW - B1. III-Nitrides

KW - B1. Nitrides

UR - http://www.scopus.com/inward/record.url?scp=84995584112&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2016.07.044

DO - 10.1016/j.jcrysgro.2016.07.044

M3 - Article

VL - 456

SP - 58

EP - 66

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

ER -

ID: 9535299