RYO YOKOGAWA

Last Updated :2025/06/09

Affiliations, Positions
Hiroshima University
E-mail
yokogawahiroshima-u.ac.jp

Basic Information

Academic Degrees

  • Meiji University
  • Meiji University

Educational Activity

Course in Charge

  1. 2025, Undergraduate Education, First Semester, Experiments in Electrical Engineering Electronics and System Engineering I
  2. 2025, Undergraduate Education, First Semester, Experiments in Electrical Engineering Electronics and System Engineering I
  3. 2025, Undergraduate Education, Second Semester, Experiments in Electrical Engineering Electronics and System Engineering II
  4. 2025, Undergraduate Education, Second Semester, Experiments in Electrical Engineering Electronics and System Engineering II
  5. 2025, Undergraduate Education, First Semester, Basic Experiments in Electrical Engineering I
  6. 2025, Undergraduate Education, First Semester, Basic Experiments in Electrical Engineering I
  7. 2025, Undergraduate Education, Second Semester, Basic Experiments in Electrical Engineering II
  8. 2025, Undergraduate Education, Second Semester, Basic Experiments in Electrical Engineering II

Research Activities

Academic Papers

  1. Temperature and Ge fraction dependence of broad peaks observed in Ge-rich SiGe Raman spectra by oil-immersion Raman spectroscopy, Japanese Journal of Applied Physics, 63(12), 125504-125504, 202412
  2. Evaluation of Band Structure of Single Crystalline Si-Rich SiSn thin Film, ECS Transactions, 114(2), 225-232, 20240927
  3. Optical Properties of Multilayered Staggered SiGe Nanodots Depending on Si Spacer Growth Temperature, ECS Transactions, 114(2), 207-214, 20240927
  4. ★, Determination of Ge-fraction-shift coefficients for Raman spectroscopy in all vibration modes investigated by single-crystalline bulk SiGe and its application to strain evaluation in SiGe film grown on substrate, Japanese Journal of Applied Physics, 63(3), 035503-035503, 202403
  5. Strain and optical characteristics analyses of three-dimentional self-ordered multilayered SiGe nanodots by photoluminescence and Raman spectroscopy, Japanese Journal of Applied Physics, 63(3), 03SP31-03SP31, 202402
  6. Local thermal conductivity properties of a SiGe nanowire observed by laser power sweep Raman spectroscopy, Japanese Journal of Applied Physics, 63(2), 02SP68-02SP68, 202401
  7. Strain distributions in carbon-doped silicon nanowires along [110] and [100] investigated by X-ray diffraction, Japanese Journal of Applied Physics, 63(1), 01SP11-01SP11, 202312
  8. Evaluation of Anisotropic Biaxial Stress in Extremely-Thin Body (100) Silicon-Germanium-on-Insulator p-Type Metal-Oxide-Semiconductor Field-Effect-Transistor by Oil-Immersion Raman Spectroscopy, ECS Transactions, 112(1), 37-43, 202309
  9. Temperature Dependence of Raman Peak Shift in Single-Crystalline Silicon-Germanium, ECS Journal of Solid State Science and Technology, 12(6), 064004-064004, 202306
  10. Analysis of InGaAs/InP p-I-n Photodiode Failed by Electrostatic Discharge, Journal of Electronic Materials, 52(8), 5150-5158, 20230524
  11. Evaluation of Strain-Relaxation of Carbon-Doped Silicon Nanowires and Its Crystal Orientation Dependence Using X-Ray Diffraction Reciprocal Space Mapping, Journal of Electronic Materials, 52(8), 5140-5149, 20230523
  12. Inelastic X-ray Scattering Measurement on Single-Crystalline GeSn Thin Film, Journal of Electronic Materials, 52(8), 5128-5133, 20230508
  13. Conformal deposition of WS2 layered film by low-temperature metal-organic chemical vapor deposition, Japanese Journal of Applied Physics, 62(SG), SG1048-SG1048, 202305
  14. Effect of sawing damage on flexibility of crystalline silicon wafers for thin flexible silicon solar cells, Japanese Journal of Applied Physics, 62(1), 20230101
  15. Non-seed chemical bath deposition of ZnO films in a rotating continuous flow reactor with various carboxylic acids and their application to transparent conductive films, CRYSTENGCOMM, 24(47), 8294-8302, 202212
  16. Distribution Evaluation of Optical Properties in Silicon Germanium Films Grown on Silicon Substrates with Graded Silicon Germanium Buffer Layers, ECS Transactions, 109(4), 367-374, 20220930
  17. Investigation of Band Structure in Strained Single Crystalline Si1-X Sn X , ECS Transactions, 109(4), 359-366, 20220930
  18. Evaluation of Strained Group IV Semiconductor Devices by Oil-Immersion Raman Spectroscopy, ECS Transactions, 109(4), 351-357, 202209
  19. ★, Study on phonon lifetime in bulk silicon–germanium through observation of acoustic phonon spectra broadening by inelastic x-ray scattering, Applied Physics Letters, 121(8), 082105-082105, 20220822
  20. Modification and Characterization of Interfacial Bonding for Thermal Management of Ruthenium Interconnects in Next-Generation Very-Large-Scale Integration Circuits, ACS Applied Materials and Interfaces, 14(5), 7392-7404, 20220209
  21. Atomic mass dependency of a localized phonon mode in SiGe alloys, AIP Advances, 11(11), 115225-115225, 202111
  22. Dependency of a localized phonon mode intensity on compositional cluster size in SiGe alloys, AIP Advances, 11(7), 075017-075017, 202107
  23. Thermal conductivity and inelastic X-ray scattering measurements on SiGeSn polycrystalline alloy, Japanese Journal of Applied Physics, 60(SB), SBBF11-SBBF11, 202105
  24. Phonon properties of group IV materials for thermoelectric applications, 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021, 20210408
  25. Effect of Growth Parameters on MoS2Film Quality Deposited by Low-Temperature MOCVD Using I-Pr2DADmo(CO)3and (t-C4H9)2S2, ECS Transactions, 104(3), 3-15, 2021
  26. Evaluation of Mo(1-x)W xs Alloy Fabricated by Combinatorial Film Deposition, ECS Transactions, 104(3), 21-28, 2021
  27. Strain evaluation in Ge and Sn implanted Si layers with laser and rapid thermal annealing, Materials Science in Semiconductor Processing, 120, 105282-105282, 202012
  28. Origin of carrier lifetime degradation in floating-zone silicon during a high-temperature process for insulated gate bipolar transistor, Japanese Journal of Applied Physics, 59(11), 115503-1-115503-6, 202011
  29. Evaluation of Thermal Conductivity Characteristics in Polycrystalline Silicon - The Effect of Nanostructure in the Grains, ECS Transactions, 98(5), 437-446, 202009
  30. Evaluation of Silicon Nitride Film Formed by Atomic Layer Deposition on the Silicon Substrate with Trench Structure Using Angle-Resolved Hard X-ray Photoelectron Spectroscopy, ECS Transactions, 98(3), 113-120, 202009
  31. Evaluation of Thermal Expansion Coefficient in Ge1-x Sn x Nanowire Using Reciprocal Space Mapping, ECS Transactions, 98(5), 481-490, 202009
  32. Evaluation of Temperature and Germanium Concentration Dependence of EXAFS Oscillations in Si-Rich Silicon Germanium Thin Films, ECS Transactions, 98(5), 473-479, 202009
  33. Observation of an Unidentified Phonon Peak in SiGe Alloys and Superlattices Using Molecular Dynamics Simulation, ECS Transactions, 98(5), 533-546, 202009
  34. Evaluation of Strain-Shift Coefficients for SiSn by Raman Spectroscopy, ECS Transactions, 98(5), 291-300, 202009
  35. Evaluation of Phonon Dispersion Relation for Bulk Silicon Germanium by Inelastic X-ray Scattering, ECS Transactions, 98(5), 465-472, 202009
  36. Quantification of Ge fraction using local vibrational modes in Raman spectra of silicon germanium by oil-immersion Raman spectroscopy, Japanese Journal of Applied Physics, 59(7), 075502-075502, 20200701
  37. ★, Anomalous low energy phonon dispersion in bulk silicon-germanium observed by inelastic x-ray scattering, Applied Physics Letters, 116(24), 242104-242104, 20200615
  38. Evaluation of Sawing Damage for Thin Flexible Silicon Solar Cells, Conference Record of the IEEE Photovoltaic Specialists Conference, 2020-June, 0875-0880, 20200614
  39. Phonon dispersion of bulk Ge-rich SiGe: inelastic X-ray scattering studies, Japanese Journal of Applied Physics, 59(6), 061003-1-061003-6, 202006
  40. Stress evaluation induced by wiggling silicon nitride fine pattern using Raman spectroscopy, Japanese Journal of Applied Physics, 59(SI), SIIF03-1-SIIF03-6, 202006
  41. Thermal conductivity characteristics in polycrystalline silicon with different average sizes of grain and nanostructures in the grains by UV Raman spectroscopy, Japanese Journal of Applied Physics, 59(7), 075501-1-075501-7, 202005
  42. Anisotropic biaxial stress evaluation in metal-organic chemical vapor deposition grown Ge1-xSnx mesa structure by oil-immersion Raman spectroscopy, Thin Solid Films, 697, 137797-1-137797-5, 202003
  43. Anisotropic Biaxial Strain Evaluation in Carbon-Doped Silicon Using Water-Immersion Raman Spectroscopy, ECS Transactions, 92(4), 33-39, 201907
  44. Ultra-Thin Lightweight Bendable Crystalline Si Solar Cells for Solar Vehicles, Conference Record of the IEEE Photovoltaic Specialists Conference, 1131-1134, 201906
  45. Evaluation of thermal conductivity characteristics in Si nanowire covered with oxide by UV Raman spectroscopy, Japanese Journal of Applied Physics, 58(SD), SDDF04-1-SDDF04-5, 201906
  46. Evaluations of minority carrier lifetime in floating zone Si affected by Si insulated gate bipolar transistor processes, Japanese Journal of Applied Physics, 58(SB), SBBD07-1-SBBD07-6, 201904
  47. Determination of phonon deformation potentials and strain-shift coefficients in Ge-rich Si1-xGex using bulk Ge-rich Si1-xGex crystals and oil-immersion Raman spectroscopy, JAPANESE JOURNAL OF APPLIED PHYSICS, 57(10), 106601-1-106601-6, 201810
  48. Strain Evaluation of Laser-annealed SiGe Thin Layers, ECS Transactions, 86(7), 59-65, 201809
  49. Determination of Phonon Deformation Potentials in Carbon-doped Silicon, ECS Transactions, 86(7), 419-425, 201809
  50. Evaluation of Anisotropic Three-Dimensional Strain Relaxation in Stripe-Shaped Ge1-xSnx Mesa Structure, ECS Transactions, 86(7), 329-336, 201809
  51. Evaluation of Laterally Graded Silicon Germanium Wires for Thermoelectric Devices Fabricated by Rapid Melting Growth, ECS Transactions, 86(7), 87-93, 201809
  52. Evaluation of Anisotropic Biaxial Stress Induced Around Trench Gate of Si Power Transistor Using Water-Immersion Raman Spectroscopy, Journal of Electronic Materials, 47, 1-6, 20180503
  53. Miniaturized planar Si-nanowire micro-thermoelectric generator using exuded thermal field for power generation, Science and Technology of Advanced Materials, 19(1), 443-453, 201805
  54. Probing spatial heterogeneity in silicon thin films by Raman spectroscopy, Scientific Reports, 7, 16549-1-16549-8, 201711
  55. Local anisotropic strain evaluation in thin Ge epitaxial film using SiGe stressor template grown on Ge substrate by selective ion implantation, Japanese Journal of Applied Physics, 56(11), 110313-1-110313-4, 20171101
  56. Enhanced nickelidation rate in silicon nanowires with interfacial lattice disorder, Journal of Applied Physics, 122(14), 144305-1-144305-7, 201710
  57. Evaluation of controlled strain in silicon nanowire by UV Raman spectroscopy, Japanese Journal of Applied Physics, 56(6), 06GG10-1-06GG10-5, 20170601
  58. Biaxial stress evaluation in GeSn film epitaxially grown on Ge substrate by oil-immersion Raman spectroscopy, Japanese Journal of Applied Physics, 55(9), 091301-1-091301-4, 20160901
  59. Origin of additional broad peaks in Raman spectra from thin germanium-rich silicon-germanium films, Applied Physics Express, 9(7), 071301-1-071301-4, 20160701
  60. In-plane biaxial strain evaluation induced in Ge1-xSnx films using oil-immersion raman spectroscopy, ECS Transactions, 75(8), 589-597, 2016
  61. Crystallinity evaluation of low temperature polycrystalline silicon thin film using UV/visible Raman spectroscopy, ECS Transactions, 72(4), 249-255, 2016
  62. Evaluation of anisotropic biaxial stress in Si1-xGex/Ge mesa-structure by oil-immersion raman spectroscopy, ECS Transactions, 66(4), 39-45, 2015
  63. On the origin of the gate oxide failure evaluated by Raman spectroscopy, ECS Transactions, 66(4), 237-243, 2015
  64. Evaluation of Anisotropic Biaxial Stress in Thin Strained-SiGe Layer Using Surface Enhanced Raman Spectroscopy, ECS Transactions, 64(6), 841-847, 201410

Social Activities

History as Committee Members

  1. Organizing Committee, 2021, 2022, 19th International Conference on Defects-Recognition, Imaging and Physics in Semiconductors (DRIP XIX)

History as Peer Reviews of Academic Papers

  1. 2025, Silicon, Others, Referee
  2. 2024, Applied Physics Letter, Others, Referee
  3. 2023, Journal of Electronic Materials, Others, Referee
  4. 2020, Japanese Journal Applied Physics, Others, Referee
  5. 2020, ACS Omega, Others, Referee