Band alignment and enhanced breakdown field of simultaneously oxidized and nitrided Zr film on Si

Yew Hoong Wong,Kuan Yew Cheong

doi:10.1186/1556-276x-6-489

Abstract

The band alignment of ZrO2/interfacial layer/Si structure fabricated by simultaneous oxidation and nitridation of sputtered Zr on Si in N2O at 700°C for different durations has been established by using X-ray photoelectron spectroscopy. Valence band offset of ZrO2/Si was found to be 4.75 eV, while the highest corresponding conduction offset of ZrO2/interfacial layer was found to be 3.40 eV; owing to the combination of relatively larger bandgaps, it enhanced electrical breakdown field to 13.6 MV/cm at 10-6 A/cm2.

Highlights

Application of high dielectric constant () materials as future gate dielectrics on Si-based metal oxide semiconductor (MOS) devices has driven a tremendous research to realize an ultra-large-scale integrated circuitry with high performance and low power consumption [1,2,3]
Of various investigated high materials, ZrO2 is being considered as a potential gate dielectric for the near future generation technology nodes
It has been reported that excellent electrical properties of MOS capacitors that incorporated ZrO2 thin film as gate dielectric [4,5]

Summary

Background

Application of high dielectric constant () materials as future gate dielectrics on Si-based metal oxide semiconductor (MOS) devices has driven a tremendous research to realize an ultra-large-scale integrated circuitry with high performance and low power consumption [1,2,3]. Of various investigated high materials, ZrO2 is being considered as a potential gate dielectric for the near future generation technology nodes. It has been reported that excellent electrical properties of MOS capacitors that incorporated ZrO2 thin film as gate dielectric [4,5]. Putkonen et al [5] and Niinisto et al [4] have obtained the breakdown fields of ZrO2 at 6.0 and 9.5 MV/cm, respectively, at leakage current density of 10-2 A/cm. The leakage characteristic and electrical breakdown field of gate dielectric are basically dependent on the bandgap of the dielectric and on the band alignment with Si [8,9]. To use ZrO2 as gate dielectric in MOS capacitors, it should have sufficiently high band offsets with Si (> 1.00 eV) for both holes (valence band offset) and electrons (conduction band offset), so that

Results and discussion

Conclusions

Methods

Robertson J

21. Shirley DA