Comparison of electrical characteristics for SiONx and HfZrOx gate dielectrics of MOSFETs with decoupled plasma nitridation treatment

Comparative Investigation of Flat-Band Voltage Modulation by Nitrogen Plasma Treatment for Advanced HKMG Technology

“…As the physical gate length of RMG scaling down to below 14nm for sub-7nm technology node, the gap filling volume becomes rigorous and the V T tuning capability by this method turns inadequate for CMOS IC applications. 8 To realize a large V T adjustment range with a more simplified stack structure and film thickness control process as well as no degradation in mobility and reliability of devices, a series of novel methods have been proposed, including decoupled plasma nitridation, 9,10 impurity doped high-k dielectric, 11,12 SiH 4 -soak of barrier layer, 13 ion implantation in work function metal, 14,15 and high-k capping layer with dipole. 16 Among these new technologies, the approach of nitrogen plasma treatment on the multi-layer high-k/metal-gate (HKMG) stack demonstrates a simplified process cost and a strong modulation ability; several initial experimental results and hypothetical predictions are published.…”