Surface Sculpting with Ion Beams

Ion beam sculpting for advanced photonics structures

The interaction of kV energy ion beams at oblique incidence with surfaces creates ripples or periodic patterns due to mass transport. 
In this project we are investigating the creation of sawtooth patterns that are then covered with thin film multilayers for structures that resemble blazed diffraction gratings.

Diagram of experimental setup consisting of a gridded ion source incident on an angled fixture oriented such that the center of the substrate is in the center of the beam and all upstream surfaces are Si.
AFM data for flat Si samples bombarded with 75° off normal Xe+. Shown in (a), slopes are selected along the ion beam projection and transverse roughness develops. Over time (b) the features coarsen and stabilize.
AFM images of Si sinusoidal pre-patterns and line scans. (a) Uniform sinusoidal pre-pattern following normal incidence Ar+ etch. (b) Sinusoidal pre-pattern following varying times of 75° off normal Xe+ bombardment. (c) Etched Si pre-pattern after 50 s with the ion beam projection labeled; Roughness on the facets is ~ 3 Å. (d) Etched Si pre-pattern after 250 s; Roughness on the facets is ~ 20 Å.


Project funded by the National Science Foundation

Selected publications