Consequences of simultaneous exposure of inorganic solids to excimer laser light and an electron beam
- Department of Physics, Washington State University, Pullman, WA (USA)
- Pacific Northwest Laboratory, Richland, WA (USA)
In previous work we examined the changes in surface topography of sodium trisilicate glass (Na{sub 2}O{center dot}3SiO{sub 2}) with exposure to pulsed 248-nm excimer laser light at fluences of 2.6--5 J/cm{sup 2} (per laser pulse), as well as the character of the products emitted from the glass surface (e.g., {plus minus} ions, electrons, ground state and excited neutral atoms and molecules). At fluences above a threshold, ablative etching occurs only after a number of preliminary laser pulses. In this work, we show a dramatic synergism in the ablation process by simultaneous bombardment of the glass surface with 0.5--2 keV electrons {ital and} laser pulses. Extensive etching can be initiated immediately and sustained indefinitely at subthreshold fluences. Reflection electron energy loss spectroscopy performed on electron-bombarded surfaces shows band gap states growing with exposure. We propose that surface and near-surface defects produced by inelastic scattering of the electron beam provide single-photon absorption centers, facilitating etching at subthreshold fluences. The potential for single-photon driven etching/ablation of other wide band gap dielectric materials is also discussed. These studies also support the hypothesis that etching and damage of such surfaces can occur after prolonged exposure to laser irradiation alone due to an accumulation of absorption centers.
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6550989
- Journal Information:
- Journal of Applied Physics; (USA), Vol. 68:4; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
The interaction of ultraviolet excimer laser light with sodium trisilicate
Quantitative and ultrastructural studies of excimer laser ablation of the cornea at 193 and 248 nanometers
Related Subjects
GLASS
PHYSICAL RADIATION EFFECTS
SODIUM SILICATES
ABLATION
ELECTRON BEAMS
ENERGY GAP
ENERGY-LEVEL DENSITY
ETCHING
EXCIMER LASERS
KEV RANGE 01-10
LASER RADIATION
PULSES
ALKALI METAL COMPOUNDS
BEAMS
ELECTROMAGNETIC RADIATION
ENERGY RANGE
GAS LASERS
KEV RANGE
LASERS
LEPTON BEAMS
OXYGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
RADIATIONS
SILICATES
SILICON COMPOUNDS
SODIUM COMPOUNDS
SURFACE FINISHING
360603* - Materials- Properties