Potassium hydroxide (KOR) etching was used to create four sided pyramids for potential use in vacuum microelectronic devices. Optimal structures were found to be approximately 2 microns on a side and 2.2 microns high. KOM etched the silicon at 1200 A/mm in the vertical direction. A slight overetch period insured that the oxide mask was undercut completely away and the pyramids came to a sharp point, but were not attacked. Surface damage as a result of the KOH etching was minimal.
Johnson, Joseph A.
"Microfabrication of Field Emitter Tips for Vacuum Microelectronic Devices,"
Journal of the Microelectronic Engineering Conference: Vol. 4
, Article 23.
Available at: http://scholarworks.rit.edu/ritamec/vol4/iss1/23