Author_Institution :
Dept. of Electron. Eng., Ming Chuan Univ., Taoyuan, Taiwan
Abstract :
The thickness and temperature dependence of the CeO2 dielectric reliability characteristics of metal-oxide-semiconductor capacitors is studied. The dielectric breakdown strength (Ebd) of CeO2 thin films decreases with increasing temperature. The Weibull slope of the charge-to-breakdown (Qbd) statistics is a function of the dielectric thickness. However, it is independent of temperature. In this work, the Weibull slope was calculated by the method of maximum-likelihood estimation. At room temperature, the Weibull slopes with thicknesses of 7.3, 11.2, and 13.1 nm are about 1.57, 3.28, and 4.41, respectively. According to a cell-based analytic model, the effectively stress-induced defect size (a0) in CeO2 in the breakdown event was determined to be about 1-2 nm. Therefore, the capture cross section of the generated defects is on the order of 10-14 cm2, which indicated that the defects were neutral centers. In addition, a comparison with SiO2- and HfO2-gated capacitors was made.
Keywords :
MOS capacitors; Weibull distribution; cerium compounds; electric breakdown; maximum likelihood estimation; thin films; CeO2; Weibull slope; cell-based analytic model; dielectric breakdown strength; dielectric reliability; dielectric thickness; maximum-likelihood estimation; metal-oxide-semiconductor capacitors; stress-induced defect size; temperature 293 K to 298 K; temperature dependence; thin films; Dielectric breakdown; Dielectrics; Logic gates; Reliability; Stress; Temperature measurement; $hbox{CeO}_{2}$; Weibull slope; dielectric reliability; stress-induced defect size;
