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We present results of a comprehensive reliability evaluation of a 2T-2C, 4Mb, Ferroelectric Random Access Memory embedded within a standard 130nm, 5LM Cu CMOS platform. Wear-out free endurance to 5.4x10 13 cycles and data retention equivalent of 10 years at 85°C is demonstrated. The results show that the technology can be used in a wide range of applications including embedded processing.

The distribution of breakdown times of thin film dielectrics, stressed in a constant voltage mode, is generally interpreted in terms of percolation theory of dielectric breakdown. The percolation model suggests that relative distribution of failure times (normalized to the mean) should narrow down considerably for thicker dielectrics. Explicitly contradicting this prediction, we find a larger distribution of failure times even for relatively thick polycrystalline oxides. We use atomic force microscopy and conductive AFM measurements to confirm that breakdown in these films are primarily localized in the grain boundaries, decorated with large number of pre-existing defects. The classical percolation model-adapted to this specific situation of spatially localized trap generation-offers an intuitive explanation of the breadth of the failure time distribution in thick polycrystalline dielectric. The theory offers an opportunity to optimize the intrinsic trade-off between variability and reliability in polycrystalline films. V

A simple design for evaluating the X-Y distribution of electric fields is presented. The apparatus is optical fibre-coupled and allows measurements without physical contact. The details of the device, some apolications and its potential use in various fields are discussed.

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