Methods for RFSOI Damascene Tungsten Contact Etching

GLOBALFOUNDRIES has ramped its 180nm generation RFSOI foundry technology into high volume production at multiple 200mm and 300mm fabricators. This RFSOI technology was optimized primarily for sub-6GHz RF switches, tuners, and low noise amplifiers used in cell phone front-end-modules. The thin SOI wafer top silicon layer presents challenges in contact etching and this paper summarizes the optimization of contact etching to significantly reduce the final contact dielectric thickness consumption and improve copper M1 wire to FET gate polysilicon (M1-Poly) shorting yield.