Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy

Fumikazu Murakami; Shinji Ueyama; Kenji Suzuki; Ingi Kim; Inkeun Baek; Sangwoo Bae; Dougyong Sung; Myungjun Lee; Sungyoon Ryu; Yusin Yang; Masayoshi Tonouchi

doi:10.1038/s41377-025-01911-0

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Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy

Original Articles

- Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy
- Light: Science & Applications Vol. 14, Issue 8, Pages: 2279-2288(2025)
- Affiliations：
  
  1.Department of Electrical and Computer Engineering, Rice University, 6100 Main St., Houston, TX 77005, USA
  2.Advanced Equipment Lab, Samsung Device Solutions R&D Japan, 2-7 Sugasawa-cho, Yokohama Tsurumi-ku, Kanagawa 230-0027, Japan
  3.Core Technology R&D Team, Global Manufacturing & Infra Technology, Samsung Electronics Co. Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, Republic of Korea
  4.Advanced Process Development Team 4, Semiconductor R&D Center, Samsung Electronics Co. Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, Republic of Korea
  5.Metrology & Inspection Technology Team, Global Manufacturing & Infra Technology, Samsung Electronics Co. Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, Republic of Korea
  6.Process Development, Semiconductor R&D Center, Samsung Electronics Co. Ltd., 1-1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, Republic of Korea
  7.Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871, Japan
  8.Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
- Author bio：
  
  Masayoshi Tonouchi (tonouchi@okayama-u.ac.jp)
- Funds：
- DOI：10.1038/s41377-025-01911-0
  CLC：
- Received：30 July 2024，
  
  Revised：11 April 2025，
  
  Accepted：26 May 2025，
  
  Published Online：20 June 2025，
  
  Published：31 August 2025
- Accepted：
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Murakami, F. et al. Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy. Light: Science & Applications, 14, 2279-2288 (2025).
DOI：

Murakami, F. et al. Non-contact and nanometer-scale measurement of PN junction depth buried in Si wafers using terahertz emission spectroscopy. Light: Science & Applications, 14, 2279-2288 (2025). DOI： 10.1038/s41377-025-01911-0.

摘要

Abstract

Buried channel array transistors enable fast and high-density integrated devices. The depth of the PN junction and carrier dynamics at the depletion layer in silicon wafers have a crucial influence on their performance and reliability. Therefore

rapid and non-contact/non-destructive inspection tools are necessary to accelerate the semiconductor industry. Despite the great efforts in this field

realizing a technique to probe the junction depth and carrier dynamics at the PN junction inside wafers remains challenging. Herein

we propose a new approach to access PN junctions embedded in wafers using terahertz (THz) emission spectroscopy. THz emission measurements and simulations demonstrate that the amplitude and polarity of THz emissions reflect the junction depth and carrier dynamics at the PN junctions. It allows us to evaluate the junction depth non-destructively with nanometer-scale accuracy

surpassing the limits of traditional techniques. Laser-induced THz emission spectroscopy is a promising method for the sensitive and non-contact/non-destructive evaluation of Si wafers and will benefit the modern semiconductor industry.

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references

Kim, K. Future silicon technology. in Proceedings of the European Solid-State Device Research Conference . (IEEE, Bordeaux, France, 2012) pp 1–6.

Hong, S. Memory technology trend and future challenges. in Proceedings of 2010 International Electron Devices Meeting . (IEEE, San Francisco, CA, USA, 2010) pp 12.4.1–12.4.4.

Beyne, E. The rise of the 3rd dimension for system intergration. in Proceedings of 2006 IEEE International Interconnect Technology Conference . (IEEE, Burlingame, CA, USA, 2006) pp 1–5.

Kim, K. From the future Si technology perspective: challenges and opportunities. in Proceedings of 2010 International Electron Devices Meeting . (IEEE, San Francisco, CA, USA, 2010) pp 1.1.1–1.1.9.

Hwang, C. S. Prospective of semiconductor memory devices: from memory system to materials. Adv. Electron. Mater. 1 , 1400056 (2015)..

Hisamoto, D. et al. FinFET-a self-aligned double-gate MOSFET scalable to 20 nm. IEEE Trans. Electron Devices 47 , 2320–2325 (2000)..

Xiao, H. 3D IC Devices, Technologies, and Manufacturing . (SPIE Press, Bellingham, Washington, 2016).

Cho, M. H. et al. An innovative indicator to evaluate DRAM cell transistor leakage current distribution. IEEE J. Electron Devices Soc. 6 , 494–499 (2018)..

Sun, M., Baac, H. W. & Shin, C. Simulation study: the impact of structural variations on the characteristics of a Buried-Channel-Array Transistor (BCAT) in DRAM. Micromachines 13 , 1476 (2022)..

Yang, C. M. et al. Scanning spreading resistance microscopy for doping profile in saddle-fin devices. IEEE Trans. Nanotechnol. 16 , 999–1003 (2017)..

Yang, T. & Lin, X. W. Trap-assisted dram row hammer effect. IEEE Electron Device Lett. 40 , 391–394 (2019)..

Kim, K. Y., Min, K. K. & Park, B. G. Trap-Induced data-retention-time degradation of DRAM and improvement using dual work-function metal gate. IEEE Electron Device Lett. 42 , 38–41 (2021)..

McPhail, D. S. Applications of secondary ion mass spectrometry (SIMS) in materials science. J. Mater. Sci. 41 , 873–903 (2006)..

Borden, P. Junction depth measurement using carrier illumination. AIP Conf. Proc. 550 , 175–180 (2001)..

Geiler, H. D. et al. Nondestructive evaluation of as-implanted and annealed ultra shallow junctions by photothermal and photoluminescence heterodyne techniques. Nucl. Instrum. Methods Phys. Res. Sect. B 237 , 30–34 (2005)..

Clarysse, T. et al. Junction and profile analysis using carrier illumination. MRS Online Proc. Libr. 717 , 73 (2002)..

Borden, P. et al. Nondestructive profile measurements of annealed shallow implants. J. Vac. Sci. Technol. B 18 , 602–604 (2000)..

Clarysse, T. et al. Carrier illumination for characterization of ultrashallow doping profiles. J. Vac. Sci. Technol. B 22 , 439–443 (2004)..

Yoo, W. S. et al. Multi-wavelength Raman and photoluminescence characterization of implanted n + /p junctions under various rapid thermal annealing conditions. AIP Conf. Proc. 1496 , 156–159 (2012)..

Hönicke, P. et al. Depth profile characterization of ultra shallow junction implants. Anal. Bioanal. Chem. 396 , 2825–2832 (2010)..

Musca, C. A. et al. Junction depth measurement in HgCdTe using laser beam induced current (LBIC). J. Electron. Mater. 28 , 603–610 (1999)..

Hur, C. W. & Lee, K. C. The measurement of p-n junction depth by SEM. J. Inf. Commun. Converg. Eng. 5 , 324–327 (2007)..

Leitenstorfer, A. et al. The 2023 terahertz science and technology roadmap. J. Phys. D 56 , 223001 (2023)..

Rana, D. S. & Tonouchi, M. Terahertz emission functionality of high-temperature superconductors and similar complex systems. Adv. Optical Mater. 8 , 1900892 (2020)..

Wais, M. et al. Transition from diffusive to superdiffusive transport in carbon nanotube networks via nematic order control. Nano Lett. 23 , 4448–4455 (2023)..

Murakami, F. et al. Probing photocarrier dynamics in a Bi 2 Te 3 –Te eutectic p–n junction with a laser terahertz emission microscope. APL Mater. 11 , 031102 (2023)..

Kampfrath, T. et al. Coherent terahertz control of antiferromagnetic spin waves. Nat. Photonics 5 , 31–34 (2011)..

Jungfleisch, M. B. et al. Control of terahertz emission by ultrafast spin-charge current conversion at Rashba interfaces. Phys. Rev. Lett. 120 , 207207 (2018)..

Chen, X. H. et al. Generation and control of terahertz spin currents in topology-induced 2D ferromagnetic Fe 3 GeTe 2 |Bi 2 Te 3 heterostructures. Adv. Mater. 34 , 2106172 (2022)..

Zhang, X. C. & Auston, D. H. Optoelectronic measurement of semiconductor surfaces and interfaces with femtosecond optics. J. Appl. Phys. 71 , 326–338 (1992)..

Shah, J. Ultrafast Spectroscopy of Semiconductors and Semiconductor Nanostructures . (Springer, Berlin, Heidelberg, 1999).

Othonos, A. Probing ultrafast carrier and phonon dynamics in semiconductors. J. Appl. Phys. 83 , 1789–1830 (1998)..

Zhang, X. C. et al. Generation of femtosecond electromagnetic pulses from semiconductor surfaces. Appl. Phys. Lett. 56 , 1011–1013 (1990)..

Tonouchi, M. Simplified formulas for the generation of terahertz waves from semiconductor surfaces excited with a femtosecond laser. J. Appl. Phys. 127 , 245703 (2020)..

Yang, D. X. et al. Rapid, noncontact, sensitive, and semiquantitative characterization of buffered hydrogen-fluoride-treated silicon wafer surfaces by terahertz emission spectroscopy. Light 11 , 334 (2022)..

Yang, D. X. et al. Noncontact evaluationof the interface potential in VO 2 /Si heterojunctions across metal– insulator phase transition. Appl. Phys. Lett. 122 , 041601 (2023)..

Yang, D. X. & Tonouchi, M. Understanding terahertz emission properties from a metal–insulator–semiconductor structure upon femtosecond laser illumination. J. Appl. Phys. 130 , 055701 (2021)..

Yang, D. X. & Tonouchi, M. Quantifying flat-band voltage in Si metal-oxide-semiconductor structures: an evaluation via Terahertz Emission Spectroscopy (TES). Int. J. High Speed Electron. Syst. 33 , 2440018 (2024)..

Mochizuki, T. et al. Probing the surface potential of oxidized silicon by assessing terahertz emission. Appl. Phys. Lett. 110 , 163502 (2017)..

Sakai, Y. et al. Visualization of GaN surface potential using terahertz emission enhanced by local defects. Sci. Rep. 5 , 13860 (2015)..

Murakami, F. et al. Enhanced luminescence efficiency in Eu-doped GaN superlattice structures revealed by terahertz emission spectroscopy. Commun. Mater. 4 , 100 (2023)..

Green, M. A. & Keevers, M. J. Optical properties of intrinsic silicon at 300 K. Prog. Photovolt. 3 , 189–192 (1995)..

Neu, J. & Schmuttenmaer, C. A. Tutorial: an introduction to terahertz time domain spectroscopy (THz-TDS). J. Appl. Phys. 124 , 231101 (2018)..

Murakami, H. et al. Scanning laser THz imaging system. J. Phys. D 47 , 374007 (2014)..

Chaudhry, A. & Kumar, M. J. Controlling short-channel effects in deep-submicron SOI MOSFETs for improved reliability: a review. IEEE Trans. Device Mater. Reliab. 4 , 99–109 (2004)..

Suh, Y. S. et al. Modeling of boron and phosphorus implantation into (100) germanium. IEEE Trans. Electron Devices 52 , 91–98 (2005)..

Nastasi, M. & Mayer, J. W. Ion Implantation and Synthesis of Materials . (Springer, Berlin, Heidelberg, 2006).

Ziegler, J. F. Interactions of Ions with Matter http://www.srim.org http://www.srim.org (2010)..

Nashima, S. et al. Temperature dependence of o ptical and electronic properties of moderately doped silicon at terahertz frequencies. J. Appl. Phys. 90 , 837–842 (2001)..

Inoue, R., Takayama, K. & Tonouchi, M. Angular dependence of terahertz emission from semiconductor surfaces photoexcited by femtosecond optical pulses. J. Optical Soc. Am. B 26 , A14–A22 (2009)..

Mannan, A. et al. A better understanding of terahertz emission from semiconductor surfaces with a phased-array effect. AIP Adv. 11 , 125021 (2021)..

Fandio, D. J. J. et al. Zeptojoule detection of terahertz pulses by parametric frequency upconversion. Opt. Lett. 49 , 1556–1559 (2024)..

Lange, S. J. et al. Lightwave-driven long-wavelength photomultipliers. Laser Photonics Rev. 18 , 2300417 (2024)..

Coutaz, J. L., Garet, F. & Wallace, V. Principles of Terahertz Time-Domain Spectroscopy . (CRC Press, New York, 2018).

Gaubas, E. & Vanhellemont, J. Comparative study of carrier lifetime dependence on dopant concentration in silicon and germanium. J. Electrochem. Soc. 154 , H231 (2007) ..

Jacoboni, C. et al. A review of some charge transport properties of silicon. Solid-State Electron. 20 , 77–89 (1977)..

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