The study of flat-band voltage shift using arsenic ion-implantation with High-k/Metal Inserted Poly Si gate stacks

The origin of flat band voltage shift phenomena using arsenic ion-implant in High-k/Metal Inserted Poly Si (HK/MIPS) gate stacks was investigated. Arsenic ion-implantations were carried out on HfSiO and HfSiON dielectric layers. Precise arsenic profile was obtained through front and backside SIMS analysis. From the electrical and physical analysis, we verified that the flat band voltage was shifted due to an arsenic dipole formation at high-k/metal interface. The negative shift of 480 mV was obtained with the optimized arsenic ion implant condition.