Stress Induced Degradation in Sputtered ZrO2 Thin Films on Silicon for Nano-MOSFET’s
This paper deals with stress induced degradation in reactively sputtered ZrO2/Si interface deposited in N2 containing plasma and pure argon ambient. MOS C–V and I–V techniques were used for interface characterization. Leakage current and shift in flat band voltages were compared for ZrO2 films deposited with and without N2 containing plasma. The presence of nitrogen in the ZrO2 films RF sputtered in nitrogen containing plasma was verified by glancing angle X-ray diffraction (XRD). The effect of post deposition annealing and current stress carried out on the samples deposited in different ambient was investigated. Electrical and reliability characteristics of annealed devices were found to be better than non annealed samples. The flat band voltage shifts towards negative value on being stressed, indicating positive charge trapping in the high k dielectric layer. The samples grown in pure argon ambient showed enhanced leakage as compared with samples grown in nitrogen ambient on application of stress.
KeywordsHigh-K Reactive sputtering Zirconium dioxide
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The authors would like to express their sincere thanks to Dr. M.D. Tiwari, Director and Prof. M. Radhakrishna for their constant support and encouragement.
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