Periodic surface structure bifurcation induced by ultrafast laser generated point defect diffusion in GaAs
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 11, 2016
- Source ID
- 10.1063/1.4946861
Entities
People
- Ben Torralva
- Michael J. Abere
- Steven M. Yalisove
Organizations
- Air Force Office of Scientific Research
- University of Michigan