Ian A. Pancham

Process development of 50-ÃIMP Ti with <2% thickness uniformity for 300-mm iLB

We have developed a 50 angstrom IMP Ti film for 300mm liner application. The process development was done on 300mm iLB Endura Platform, which combines the high bottom coverage and scalability of IMP Ti with the conformality of the CVD TXZ TiN process to address low contact resistance and good adhesion for W and Al application. The IMP technology has an advantage of significant improving the step coverage but has a limitation on obtaining a good film uniformity due to high pressure operation and coil sputtering non-uniformity. ICE technology was used to improve the coil sputtering non-uniformity and film uniformity was improved to approximately 4 percent. Further investigation revealed that the target to substrate spacing has a direct effect on film uniformity. It was found that there is optimum spacing for which great film uniformity can be achieved. The coil position between the target and substrate plays an important role as well. 1000 wafer marathon was performed and average 1.26 percent thickness uniformity was achieved. Thickness was 51 angstrom with 0.4 percent wafer to wafer repeatability.