| 摘要 |
A process for the etching of multiple layers of at least two different metals, for instance a first layer of copper and a second layer of aluminium, comprises: forming a resist (10) pattern over a first layer (18) of metal, said resist pattern having a pattern of openings (14) therein, applying a first etch solution onto said resist pattern so that at least some etch solution contacts exposed areas of the first layer of metal, etching away the majority of the depth of the first metal in exposed areas of metal in the first layer of metal, applying a second etch solution onto the resist pattern the second etch solution having a rate of etch towards the first metal as compared to the first etch solution that is at least 20% less than the millimeter/minute rate of etch of the first etch solution at the same etch solution temperature, removing the second etch solution from said resist pattern after at least the first metal layer has been etched sufficiently to expose areas of a second metal layer (6) underlying the first metal layer (8) by forming an etched first metal layer, and applying a third etch solution to said etched first metal layer, the third etch solution having a faster rate of etch towards the second metal than towards the first metal to etch into said second metal layer without destroying the etched first metal layer. The first and second etch solutions comprise solutions with a pH below 10, preferably acidic solutions, and the third etch solution comprises a basic solution with a pH of at least 10.5, preferably a solution of alkali metal hydroxide with a pH of at least 11.0 containing an oxidizing agent. <IMAGE> |
