Composite Glass Cap for Stress Relief of High Stress Barrier Metallurgy
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19
Tantalum and other high stress metals evaporated onto glass and resist lift-off structures cause the cap of the structure to bow and crack. The metal evaporated through the cracks causes bridging between the permanent metal and the metal to be lifted off. This condition ties the resist structure down, causing difficult lift-off and interlevel shorts as residual metal sticks up through the insulating layer of quartz deposited after lift-off. The curling of the cap results in poor overhang, causing the deposited metal band to be wider than the spacing defined after reactive ion etching. The functional metal pins the photoresist to the substrate, which further impedes lift-off.