Multilayer Metallurgy Incorporating a Reactive Ion Etch Stop for Aluminum on Polyimide
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Where it is desired to pattern aluminum or aluminum alloy films atop polyimide by reactive ion etching (RIE), an etch stop film comprised of a material which is not etched by a chlorinated or oxygenated etch plasma but can be etched in a fluorinated plasma is interposed between the aluminum and the polyimide. Referring to the figure, a thin layer of an etch stop material such as tungsten (W) is deposited on the polyimide 2. The aluminum- based film 4 is next deposited. Following photoresist deposition and patterning, the aluminum film 4 is etched in a chlorinated RIE process leaving the aluminum structures, e.g., 4, with photoresist 6 on top. Photoresist 6 is next removed by an oxygen plasma RIE process step.