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6CCVD Research

Study of photoinduced nonthermal melting of 4H-SiC under femtosecond pulse laser irradiation based on time-dependent density functional theory simulations

At a Glance

Section titled ā€œAt a Glanceā€
MetadataDetails
Publication Date2024-12-23
JournalJournal of Applied Physics
AuthorsSen Yang, Yucheng Lan, Gaoming Li, Bo Peng, Hui Guo
InstitutionsXiā€™an Jiaotong University, Xiā€™an UniIC Semiconductors (China)
Citations4

Abstract

Section titled ā€œAbstractā€

Silicon carbide (SiC) exhibits superior properties, including a wide bandgap, high breakdown electric field, high thermal conductivity, high electron saturation drift velocity, strong radiation resistance, and excellent chemical stability, making it highly suitable for power device applications. In the substrate slicing process for fabricating SiC power devices, pulsed laser technology provides several advantages over traditional diamond wire sawing, including a smaller heat-affected zone, reduced thermal defects, higher precision, and improved efficiency. To gain a deeper understanding of the interaction between femtosecond lasers and 4H-SiC materials at the atomic scale, this study employs real-time time-dependent density functional theory simulations, incorporating carrier cooling to maintain detailed balance. The analysis examines the evolution of carrier number, density of states, Si-C bond length, and atomic disorder over time under photoexcitation at varying wavelengths and intensities. The results indicate that ultrafast non-thermal melting in 4H-SiC arises from carrier localization, which induces uneven interatomic forces, leading to local atomic displacements, which increases atomic bond lengths and ultimately results in melting. Long-wavelength 1064 nm laser irradiation was found to cause greater atomic force imbalances and displacements than shorter wavelengths (266 and 532 nm), leading to more pronounced non-thermal melting. This study provides atomic-scale theoretical support for research on femtosecond laser processing of 4H-SiC ingots and substrates.

Tech Support

Section titled ā€œTech Supportā€

Original Source

Section titled ā€œOriginal Sourceā€

References

Section titled ā€œReferencesā€
  1. 2014 - Fundamentals of Silicon Carbide Technology: Growth, Characterization, Devices and Applications
  2. 2019 - Sawing stress of SiC single crystal with void defect in diamond wire saw slicing [Crossref]
  3. 2019 - Material removal mechanism and crack propagation in single scratch and double scratch tests of single-crystal silicon carbide by abrasives on wire saw [Crossref]
  4. 2017 - Analytical force modeling of fixed abrasive diamond wire saw machining with application to SiC monocrystal wafer processing [Crossref]
  5. 2022 - Influence of surface preprocessing on 4H-SiC wafer slicing by using ultrafast laser [Crossref]
  6. 2017 - 4H-SiC wafer slicing by using femtosecond laser double-pulses [Crossref]
  7. 2023 - Slicing of 4H-SiC wafers combining ultrafast laser irradiation and bandgap-selective photo-electrochemical exfoliation [Crossref]
  8. 2024 - Experimental study on femtosecond laser ablation of 4H-SiC substrate [Crossref]
  9. 2023 - Internal modified structure of silicon carbide prepared by ultrafast laser for wafer slicing [Crossref]
  10. 2022 - Laser slicing of 4H-SiC wafers based on picosecond laser-induced micro-explosion via multiphoton processes [Crossref]

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