Structural and Electrical Characteristics of HfO2 Film Deposited by RF Sputtering and Plasma Enhanced Atomic Layer Deposition
We report the effect of annealing on the structural and electrical properties of thin HfO2 film deposited on p <100> silicon substrate by RF sputtering and Plasma Enhanced Atomic Layer Deposition techniques (PEALD). Multiple angle ellipsometric analysis in the range 65–80° shows the variation of refractive index in the range of 1.9–2.6 for PEALD HfO2 and 2.74–2.9 for sputtered HfO2 annealed in the temperature range of 450–600 °C. Grazing incidence angle X-Ray diffraction result shows the orthorhombic film structure with <121> and <111> dominant peaks for the PEALD and sputtered HfO2 film respectively. Electrical measurements on the MIS capacitor structure shows the positive flatband voltage of 1.7 V, leakage current of the order 10−11–10−12 A/cm2 and the breakdown voltage of 36 V for PEALD deposited film at the annealing temperature of 500 °C. For the sputtered deposited film, at the same annealing temperature, the flatband voltage is 0.5 V and the leakage current density of the order 10−5–10−6 A/cm2 with a breakdown voltage of 30 V has been observed.
KeywordsEllipsometry Flatband PEALD Sputtering XRD
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