Periodic surface structure bifurcation induced by ultrafast laser generated point defect diffusion in GaAs

Journal Article · Mon Apr 11 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4946861· OSTI ID:22591580

Abere, Michael J.; Yalisove, Steven M. ^[1]; Torralva, Ben ^[2]

---

1. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2. Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

The formation of high spatial frequency laser induced periodic surface structures (HSFL) with period <0.3 λ in GaAs after irradiation with femtosecond laser pulses in air is studied. We have identified a point defect generation mechanism that operates in a specific range of fluences in semiconductors between the band-gap closure and ultrafast-melt thresholds that produces vacancy/interstitial pairs. Stress relaxation, via diffusing defects, forms the 350–400 nm tall and ∼90 nm wide structures through a bifurcation process of lower spatial frequency surface structures. The resulting HSFL are predominately epitaxial single crystals and retain the original GaAs stoichiometry.

• OSTI ID: 22591580
• Journal Information: Applied Physics Letters, Vol. 108, Issue 15; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AIR
BIFURCATION
DEFECTS
DIFFUSION
EPITAXY
GALLIUM ARSENIDES
IRRADIATION
LASERS
MONOCRYSTALS
NANOSTRUCTURES
PERIODICITY
PULSES
SEMICONDUCTOR MATERIALS
STOICHIOMETRY
STRESS RELAXATION
STRESSES
SURFACES
VACANCIES