In a conventional lithography process with Al film structure, the photo resist pattern is removed by two methods: wet
etch or wet etch combine with dry strip process.
There were some problems in these kinds of processes. Pattern collapsed after wet etch process due to the photo resist
(PR) adhesion capability reduced. Contact angle can be the index to measure the adhesion capability.
So as to prevent the pattern collapsed issue, a high-temperature plasma treatment step was added after wet etch. But it
induces another issue. IC devices fabrication in Al interconnect process, 0.5wt% Cu is generally used in Al film
deposition for better Al electron migration performance. The high-temperature Plasma with high potentiality of CuAl<sub>2</sub>
precipitation, which will form a residue cause the metal line bridge induce yield loss.
In this paper, we modify the rework procedure and lower the plasma processing temperature to the "room
temperature" to prevent the pattern collapsed issue and the CuAl<sub>2</sub> precipitation.
The modified rework procedure is not only improved the defect, WAT and yield, but also reduce the cycle time of
resist remove process.