| The current theories and models for ferroelectric thin-film memory devices are reviewed, including the phenomena of ferroelectric thin-film capacitor and ferroelectric-on-semiconductor field effect transistor such as ferroelectric phase transitions, ferroelectric hysteresis, ferroelectric switching, capacitance versus voltage, current versus voltage, and ferroelectric surface and interface. These theories and models are mostly independent of each other and none of them can cover all of those phenomena mentioned above.;The purpose of this dissertation is to propose a general ideal model for ferroelectric memory devices. A simple analytical model for ferroelectric hysteresis based on the effective field approach is proposed for the first time, which is easy to be applied to device modeling. The ferroelectric macroscopic switching model is derived from this new hysteresis model for the first time. Based on the proposed hysteresis model, the well developed semiconductor surface field effect model, and the universal Maxwell equations, the ferroelectric thin-film capacitor model and the ferroelectric-on-semiconductor field effect transistor model are also derived analytically with macroscopic approach for the first time. The parameters of these models can be extracted from the experimental results. The equivalent circuit models for these ferroelectric memory devices are proposed based on the respective physical models. The new general model for ferroelectric memory devices can be used as a tool for device design and process integration towards the development of nonvolatile ferroelectric memories. The ferroelectric memory configurations for ferroelectric thin film capacitor and field effect transistor based on the new hysteresis model are also proposed and discussed.;Some relevant work such as ferroelectric device analytical simulation (C++ source codes), numerical simulation (PISCES input files), chip layout design for ferroelectric memory devices, and experiment data is included in the appendices. |
