Fabrication of silicon waveguides without performing any silicon etching is demonstrated. The silicon waveguides are defined by the concept of “selective oxidation”. The experiment demonstrates that the waveguides formed by selective oxidation produce ultra-smooth sidewalls since etching of silicon is avoided. The Si etching usually creates damage from ion bombardment and chemical reactions that occur during plasma etching. The final waveguide also demonstrates very low light low based on optical testing which shows that no light scattering is observed. The final waveguide has a width of 1.5 μm and a height of ~80 nm. The GCA stepper is utilized to expose the SOl sample. In order to do this an alternative method of exposing a wafer piece is needed which excludes the use of a special wafer pedal. This method is also demonstrated in the paper.
"Low Less Etchless Silicon Waveguides,"
Journal of the Microelectronic Engineering Conference: Vol. 19
, Article 3.
Available at: https://scholarworks.rit.edu/ritamec/vol19/iss1/3