An investigation on the leakage current and time dependent dielectric breakdown of ferroelectric lead-zirconate-titanate thin film capacitors for memory device applications

[[abstract]]Lead-zirconate-titanate (PZT) is an interesting ferroelectric material for the application of DRAM and nonvolatile memory devices. In this work, metal-PZT-metal capacitors with Au and Pt as the top and the bottom electrodes are fabricated. The leakage current, time dependent dielectric breakdown (TDDB) lifetime and the correlation between them are studied. The leakage current is found to depend on the applied electric field in a power law relationship. The exponent in the power law relation is found to be 0.88 in the low field region (lower than 100 kV/cm) and 9.6 in the high field region (larger than 100 kV/cm). The TDDB of the PZT capacitors is measured. An extrapolation method is proposed to obtain the projected TDDB lifetime from the time to breakdown (tBD) data. The power law exponential extracted from the TDDB measurement in this method-is found to be in good agreement with that obtained from the leakage current measurement[[fileno]]2030179010041[[department]]電機工程學