Evolving the Shapes of Large Aspect Ratio Microstructures Through Plasma etching

Microstructures created in different mask layers on silicon have been engraved by reactive ion etching in the substrate. The etch characteristics like undercut, patternwall curvature, striation, kinks and bowing of ultimate structure are analysed as functions of etch process parameters. Aspect ratio as well as profile of ultimate structure and the etch rate improve from the freon-rich plasma through inorganics and peak for their combination.