Polyimide Profile Control by Dry Etching
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
This dry etching process produces a wide range of polyimide profiles for specific device fabrication having both high density circuitry and good step coverage. In a planar diode system, the polyimide etch profile may be controlled by varying the following: 1. Pressure. As the pressure increases the directionality decreases. 2. Substrate electrode self-induced DC biased voltage. As the magnitude of the negative DC bias increases, the directionality increases. 3. Etchant gas composition. For example, the addition of a small amount of CF4 to O2 plasma decreases the directionality. 4.A combination of the above three parameters. Experiments in the pressure range 30 - 280 mt, constant power 150 watts to the opposite electrode (top) / - 70 V self-induced DC bias at the substrate electrode (bottom), and 4.5-13.