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

•The gate leakage with oxynitride dielectric around 1.5 nm thickness was sensed.•The gate leakage with HfZrOx dielectric around 1.5 nm thickness was extracted.•The ON currents for both devices were measured and compared.•The difference of leakage mechanisms for both was illustrated.•We probe the discrepancy for both devices in electrical characterization.

The gate leakage with oxynitride (SiONx) as a gate dielectric is lower than that with high-K (HfZrOx) around one order at VGS = ±0.8 V under the close physical gate thickness (∼1.5 nm) and device geometry. The subthreshold swing value in n-channel device grown with SiONx plus poly-Si gate is also superior to that for high-K gate dielectric with metal gate, but the phenomenon in p-channel device is changed due to the boron penetration from gate to channel surface. On the basis of the extracted data, the entire ON current with high-K dielectric is still better than that with oxynitride. The raise-up ratio is up to the maximum 51%. Although the possible existence of nano-crystallization, trap species or oxygen vacancy in high-K is increased to indirectly advance the higher leakage, the desired benefit to promote the drive current is still approached.

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