Abstract
The effect of surface treatment on the electrical properties of ZrO2 MIS capacitor was studied with pre-H2O2 and post-diluted HCl. The interface state was reduced from 5.6 × 1013 cm-2 to 4 × 1012 cm-2. From TEM analysis, the interfacial layer reduced from 7.7 nm to 5.9 nm after H2O2 pretreatment. The dielectric constant of ZrO2 film from C-V measurement increased from 5.54 to 7.3 due to reduced interfacial layer. The Cl incorporated into ZrO2 film during post-treatment resulted in further increase of the dielectric constant. The conduction mechanism was studied. Poole-Frenkel emission was found above 450 K and at low field (< 0.6 MV/cm) for samples with only post-treatment, this is most likely caused by Zr-Cl bond breaking under high temperature. In the reliability issues, the Weibull slope was obtained from time dependent dielectric breakdown (TDDB) measurements. The extracted Weibull slope (β) of 1.2 and 0.9 were obtained from the samples with H2O2 pretreatment and with no treatment, respectively. The lifetime of the sample with H2O2 pretreatment is 2 × 106 seconds while lifetime of samples with no treatment is 2 × 104 seconds.