Plasma Enhanced Metal Liftoff
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
The liftoff process for the interconnection of integrated cir- cuits is one of the more powerful and frequently used methods for defining fine line wiring on semiconductor chips. The process consists of spin coating a wafer with sequential coatings of an underlayer 3, a barrier layer 2 and, finally, an imaging layer not shown. After a series of photolithographic steps, a reactive ion etch (RIE) step and metal 1 deposition, the wafer is placed in a suitable solvent to "lift off" the unwanted metallurgy. For a variety of reasons, the length of time that the wafer must spend in the solvent to effect complete liftoff is often extremely long, creating undesirable processing delays. The novel solution to this problem is to subject the wafer to a suitable plasma ash after metal deposition but prior to liftoff.