謝辞
本研究にあたり，古河機械金属㈱の薄善行，渡辺泰史，碓井彰各位にはご支援と有益な議論を頂きました。用いた焦電検出器はジャスコオプト社と共同開発したものであり，古河機械金属㈱の千葉善幸，砂川晴夫両氏にGaNウエハー試料の提供頂きました。また，技術的な支援を理研の鎌田優子，齋藤美紀子，庄子鉄雄，および東北大学電気通信研究所の田久長一，今野勇治の諸氏より頂きました。感謝申し上げます。
参考文献
1）C. M. Hurd, “The accurate determination of the Hall coefficient of a metal,” Journal of Scientific Instruments 42, 465 (1965).
2）T. M. Dauphinee and E. Mooser, “Apparatus for Measuring Resistivity and Hall Coefficient of Semiconductors,” Rev. Sci. Instrum. 26, 660 (1955).
3）W. G. Spitzer and H. Y. Fan, “Determination of Optical Constants and Carrier Effective Mass of Semiconductors,” Physical Review 106, 882, (1957).
4）Elizabeth Barta, “Optical constants of various heavily doped p- and n-type silicon crystals obtained by Kramers-Kronig analysis,” Infrared Physics 17, 319 (1977).
5）Katsutoshi Narita, Yasuto Hijikata, Hiroyuki Yaguchi, Sadafumi Yoshida and Shinichi Nakashima, “Characterization of Carrier Concentration and Mobility in n-type SiC Wafers Using Infrared Reflectance Spectroscopy,” Japanese Journal of Applied Physics 43, 5151 (2004).
6）S. Sugai, K. Murase, S. Katayama, S. Takaoka, S. Nishi and H. Kawamura, “Carrier density dependence of soft TO-phonon in SnTe by Raman scattering,” Solid State Communications 24, 407, (1977).
7）H. Yugami, S. Nakashima, A. Mitsuishi, A. Uemoto, M. Shigeta, K. Furukawa, A. Suzuki and S. Nakajima, “Characterization of the free-carrier concentrations in doped β-SiC crystals by Raman scattering,” J. Appl. Phys. 61, 354 (1987).
8）N. Harrick, “Semiconductor surface properties deduced from free carrier absorption and reflection of infrared radiation” J. Phys. Chem. Solids 14, 60 (1960).
9）J. Majewski and D. Matthiesen, “Quantitative infrared imaging for the measurement of dopant distribution in gallium arsenide,” J. Cryst. Growth 137, 249 (1994).
10）C. Drake, S. Deshpande, and S. Seal, “Determination of free carrier density and space charge layer variation in nanocrystalline In3+ doped tin oxides using Fourier transform infrared spectroscopy,” Appl. Phys. Lett. 89, 143116 (2006).
11）Tae-In Jeon and D. Grischkowsky, “Nature of Conduction in Doped Silicon,” Phys. Rev. Lett. 78, 1106 (1997).
12）Takeshi Nagashima and Masanori Hangyo, “Measurement of complex optical constants of a highly doped Si wafer using terahertz ellipsometry,” Applied Physics Letters 79, 3917 (2001).
13）A. J. Huber, F. Keilmann, J. Wittborn, J. Aizpurua, and R. Hillenbrand, “Terahertz near-field nanoscopy of mobile carriers in single semiconductor nanodevices,” Nano Lett. 8, 3766 (2008).
14）J. Hebling, M. C. Hoffmann, H. Y. Hwang, K.-L. Yeh, and K. A. Nelson, “Observation of nonequilibrium carrier distribution in Ge, Si, and GaAs by terahertz pump-terahertz probe measurements,” Phys. Rev. B 81, 035201 (2010).
15）K. Kawase, M. Sato, T. Taniuchi, and H. Ito, “Coherent tunable THz wave generation from LiNbO3 with monolithic grating coupler,” Appl. Phys. Lett. 68, 2483 (1996).
16）H. Minamide, T. Ikari, and H. Ito, “Frequency-agile terahertz-wave parametric oscillator in a ring-cavity configuration,” Rev. Sci. Instrum. 80, 123104 (2009).
17）H. Ito, K. Suizu, T. Yamashita, A. Nawahara, and T. Sato, “Random frequency accessible broad tunable terahertz-wave source using phase-matched 4-dimethylamino-n-methyl-4-stilbazolium tosylate crystal,” Jpn. J. Appl. Phys. 46, 7321 (2007).
18）K. Miyamoto, H. Minamide, M. Fujiwara, H. Hashimoto, and H. Ito, “Widely tunable terahertz-wave generation using an N-benzyl-2-methyl-4-nitroaniline crystal,” Opt. Lett. 33, 252-254 (2008).
19）S. Ohno, A. Hamano, K. Miyamoto, C. Suzuki, and H. Ito, “Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source,” J. Eur. Opt. Soc. Rapid Publ. 4, 09012 (2009).
20）A. Hamano, S. Ohno, H. Minamide, H. Ito, and Y. Usuki, “High-resolution imaging of electrical properties of a 2-inch-diameter gallium nitride wafer using frequency agile terahertz waves,” Jpn. J. Appl. Phys. 49, 022402 (2010).
21）R. Holm, J. Gibson, and E. Palik, “Infrared reflectance studies of bulk and epitaxial-film n-type GaAs,” J. Appl. Phys. 48, 212 (1977).
22）V. Bougrov, M. E. Levinshtein, S. L. Rumyantsev, and A. Zubrilov, Properties of Advanced Semiconductor Materials GaN, AlN, InN, BN, SiC, SiGe (John Wiley & Sons, Inc., New York, 2001).
23）A. Barker and M. Ilegems, “Infrared lattice vibrations and free-electron dispersion in GaN,” Phys. Rev. B 7, 743 (1973).
24）Y. Fu, M. Willander, Z.-F. Li, and W. Lu, “Electron mobilities, Hall factors, and scattering processes of n-type GaN epilayers studied by infrared reflection and Hall measurements,” Phys. Rev. B 67, 113313 (2003).
25） Markus Walther, Kasper Jensby, Søren Rud Keiding, Hidenori Takahashi, and Hiromasa Ito, “Far-infrared properties of DAST,” Optics Letters 25, 911-913 (2000).
26）A. Hamano, S. Ohno, H. Minamide, H. Ito, Y. Usuki, “High-Sensitivity High-Resolution Full-Wafer Imaging of the Properties of Large n-Type SiC Using the Relative Reflectance of Two Terahertz Waves”, Materials Science Forum 778, 491 (2014).
2）T. M. Dauphinee and E. Mooser, “Apparatus for Measuring Resistivity and Hall Coefficient of Semiconductors,” Rev. Sci. Instrum. 26, 660 (1955).
3）W. G. Spitzer and H. Y. Fan, “Determination of Optical Constants and Carrier Effective Mass of Semiconductors,” Physical Review 106, 882, (1957).
4）Elizabeth Barta, “Optical constants of various heavily doped p- and n-type silicon crystals obtained by Kramers-Kronig analysis,” Infrared Physics 17, 319 (1977).
5）Katsutoshi Narita, Yasuto Hijikata, Hiroyuki Yaguchi, Sadafumi Yoshida and Shinichi Nakashima, “Characterization of Carrier Concentration and Mobility in n-type SiC Wafers Using Infrared Reflectance Spectroscopy,” Japanese Journal of Applied Physics 43, 5151 (2004).
6）S. Sugai, K. Murase, S. Katayama, S. Takaoka, S. Nishi and H. Kawamura, “Carrier density dependence of soft TO-phonon in SnTe by Raman scattering,” Solid State Communications 24, 407, (1977).
7）H. Yugami, S. Nakashima, A. Mitsuishi, A. Uemoto, M. Shigeta, K. Furukawa, A. Suzuki and S. Nakajima, “Characterization of the free-carrier concentrations in doped β-SiC crystals by Raman scattering,” J. Appl. Phys. 61, 354 (1987).
8）N. Harrick, “Semiconductor surface properties deduced from free carrier absorption and reflection of infrared radiation” J. Phys. Chem. Solids 14, 60 (1960).
9）J. Majewski and D. Matthiesen, “Quantitative infrared imaging for the measurement of dopant distribution in gallium arsenide,” J. Cryst. Growth 137, 249 (1994).
10）C. Drake, S. Deshpande, and S. Seal, “Determination of free carrier density and space charge layer variation in nanocrystalline In3+ doped tin oxides using Fourier transform infrared spectroscopy,” Appl. Phys. Lett. 89, 143116 (2006).
11）Tae-In Jeon and D. Grischkowsky, “Nature of Conduction in Doped Silicon,” Phys. Rev. Lett. 78, 1106 (1997).
12）Takeshi Nagashima and Masanori Hangyo, “Measurement of complex optical constants of a highly doped Si wafer using terahertz ellipsometry,” Applied Physics Letters 79, 3917 (2001).
13）A. J. Huber, F. Keilmann, J. Wittborn, J. Aizpurua, and R. Hillenbrand, “Terahertz near-field nanoscopy of mobile carriers in single semiconductor nanodevices,” Nano Lett. 8, 3766 (2008).
14）J. Hebling, M. C. Hoffmann, H. Y. Hwang, K.-L. Yeh, and K. A. Nelson, “Observation of nonequilibrium carrier distribution in Ge, Si, and GaAs by terahertz pump-terahertz probe measurements,” Phys. Rev. B 81, 035201 (2010).
15）K. Kawase, M. Sato, T. Taniuchi, and H. Ito, “Coherent tunable THz wave generation from LiNbO3 with monolithic grating coupler,” Appl. Phys. Lett. 68, 2483 (1996).
16）H. Minamide, T. Ikari, and H. Ito, “Frequency-agile terahertz-wave parametric oscillator in a ring-cavity configuration,” Rev. Sci. Instrum. 80, 123104 (2009).
17）H. Ito, K. Suizu, T. Yamashita, A. Nawahara, and T. Sato, “Random frequency accessible broad tunable terahertz-wave source using phase-matched 4-dimethylamino-n-methyl-4-stilbazolium tosylate crystal,” Jpn. J. Appl. Phys. 46, 7321 (2007).
18）K. Miyamoto, H. Minamide, M. Fujiwara, H. Hashimoto, and H. Ito, “Widely tunable terahertz-wave generation using an N-benzyl-2-methyl-4-nitroaniline crystal,” Opt. Lett. 33, 252-254 (2008).
19）S. Ohno, A. Hamano, K. Miyamoto, C. Suzuki, and H. Ito, “Surface mapping of carrier density in a GaN wafer using a frequency-agile THz source,” J. Eur. Opt. Soc. Rapid Publ. 4, 09012 (2009).
20）A. Hamano, S. Ohno, H. Minamide, H. Ito, and Y. Usuki, “High-resolution imaging of electrical properties of a 2-inch-diameter gallium nitride wafer using frequency agile terahertz waves,” Jpn. J. Appl. Phys. 49, 022402 (2010).
21）R. Holm, J. Gibson, and E. Palik, “Infrared reflectance studies of bulk and epitaxial-film n-type GaAs,” J. Appl. Phys. 48, 212 (1977).
22）V. Bougrov, M. E. Levinshtein, S. L. Rumyantsev, and A. Zubrilov, Properties of Advanced Semiconductor Materials GaN, AlN, InN, BN, SiC, SiGe (John Wiley & Sons, Inc., New York, 2001).
23）A. Barker and M. Ilegems, “Infrared lattice vibrations and free-electron dispersion in GaN,” Phys. Rev. B 7, 743 (1973).
24）Y. Fu, M. Willander, Z.-F. Li, and W. Lu, “Electron mobilities, Hall factors, and scattering processes of n-type GaN epilayers studied by infrared reflection and Hall measurements,” Phys. Rev. B 67, 113313 (2003).
25） Markus Walther, Kasper Jensby, Søren Rud Keiding, Hidenori Takahashi, and Hiromasa Ito, “Far-infrared properties of DAST,” Optics Letters 25, 911-913 (2000).
26）A. Hamano, S. Ohno, H. Minamide, H. Ito, Y. Usuki, “High-Sensitivity High-Resolution Full-Wafer Imaging of the Properties of Large n-Type SiC Using the Relative Reflectance of Two Terahertz Waves”, Materials Science Forum 778, 491 (2014).
27）大野誠吾，伊藤弘昌，南出泰亜，濱野哲英，特許第5601562号“移動度測定装置及びその方法，並びに，抵抗率測定装置及びその方法”.
■Tunable monochromatic THz-wave light source reveals carrier properties in semiconductors
■①Seigo Ohno ②Hiroaki Minamide ③Hiromasa Ito ④Akihide Hamano
■①〜③RIKEN ④FURUKAWA CO., LTD.
①オオノ セイゴ
所属：国立研究開発法人理化学研究所（現所属：東北大学／国立研究開発法人理化学研究所）
②ミナミデ ヒロアキ ③イトウ ヒロマサ
所属：国立研究開発法人理化学研究所
④ハマノ アキヒデ
所属：古河機械金属㈱（現所属：古河電子㈱））
（月刊OPTRONICS 2016年12月号）
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