Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Seigo Ohno; Akihide Hamano; Katsuhiko Miyamoto; Chisato Suzuki; Hiromasa Ito

doi:10.2971/jeos.2009.09012

Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Seigo Ohno, Akihide Hamano, Katsuhiko Miyamoto, Chisato Suzuki, Hiromasa Ito

Research output: Contribution to journal › Article › peer-review

28 Citations (Scopus)

Abstract

We developed a method for mapping the carrier density on a semiconductor substrate surface based on terahertz (THz)-reflective measurement. Reflectivity in the THz-frequency region away from the optical phonon frequency is sensitive to the carrier density in semiconductors. However, reflectivity in the optical phonon frequency regions is around 1.0, independent of the carrier density. We developed a THz-reflective spectral imaging system using a frequency-agile, ultra-widely tunable THz source (1-40 THz). Different reflective images were obtained from GaN samples of carrier density 2.5 × 10¹⁶ cm^-3, 1.0 × 10¹⁸ cm^-3 and 1.5 × 10¹⁸ cm^-3 using 22.7 and 26.5 THz. The image contrast reflected the GaN crystals' carrier density.

Original language	English
Article number	9012
Journal	Journal of the European Optical Society
Volume	4
DOIs	https://doi.org/10.2971/jeos.2009.09012
Publication status	Published - 2009
Externally published	Yes

Keywords

Carrier density
GaN
Imaging systems
Terahertz spectroscopy

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics

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10.2971/jeos.2009.09012

Cite this

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abstract = "We developed a method for mapping the carrier density on a semiconductor substrate surface based on terahertz (THz)-reflective measurement. Reflectivity in the THz-frequency region away from the optical phonon frequency is sensitive to the carrier density in semiconductors. However, reflectivity in the optical phonon frequency regions is around 1.0, independent of the carrier density. We developed a THz-reflective spectral imaging system using a frequency-agile, ultra-widely tunable THz source (1-40 THz). Different reflective images were obtained from GaN samples of carrier density 2.5 × 1016 cm-3, 1.0 × 1018 cm-3 and 1.5 × 1018 cm-3 using 22.7 and 26.5 THz. The image contrast reflected the GaN crystals' carrier density.",

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AU - Hamano, Akihide

AU - Miyamoto, Katsuhiko

AU - Suzuki, Chisato

AU - Ito, Hiromasa

PY - 2009

Y1 - 2009

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AB - We developed a method for mapping the carrier density on a semiconductor substrate surface based on terahertz (THz)-reflective measurement. Reflectivity in the THz-frequency region away from the optical phonon frequency is sensitive to the carrier density in semiconductors. However, reflectivity in the optical phonon frequency regions is around 1.0, independent of the carrier density. We developed a THz-reflective spectral imaging system using a frequency-agile, ultra-widely tunable THz source (1-40 THz). Different reflective images were obtained from GaN samples of carrier density 2.5 × 1016 cm-3, 1.0 × 1018 cm-3 and 1.5 × 1018 cm-3 using 22.7 and 26.5 THz. The image contrast reflected the GaN crystals' carrier density.

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KW - Imaging systems

KW - Terahertz spectroscopy

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Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source

Abstract

Keywords

ASJC Scopus subject areas

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