Method of fabricating metallized substrates using an organic etch block

Abstract

A method of patterning a metallized substrate using a thin partially cured etch block layer. In accordance with the method, a substrate is provided and a layer of metal, such as aluminum, is deposited on the substrate. A thin layer of organic dielectric material, such as polyimide, is deposited over the layer of metal. The thin layer of organic dielectric material is deposited to a thickness on the order one micron, for example, which is thin enough to have etch resistance when acting as an etch block layer for subsequent wet etch patterning of the layer of metal, and thick enough to have no pinhole defects. The deposited thin organic dielectric layer is then partially cured. The underlying layer of metal is then patterned and wet etched using the partially cured thin organic dielectric material as the blocking layer. An additional thick layer of organic dielectric material is then deposited or coated over the patterned layer of metal and partially cured organic dielectric layer. The partially cured organic dielectric layer and the additional thick organic dielectric material are then simultaneously full cured. Upon curing, the partially cured organic dielectric layer conforms to the etched underlying layer of metal.