This thesis explores three areas of research in ferroelectric memories: behavioral modeling of ferroelectric capacitors, circuit design, and architecture.
We propose a behavioral macromodel for ferroelectric capacitors that can be integrated into HSPICE for both small-signal and large-signal circuit simulations. The proposed model relies on both hysteresis loop and pulse measurements of the capacitor. We demonstrate the accuracy of the model by predicting the bitline voltage in a ferroelectric memory array testchip. We use the model, in conjunction with HSPICE, to verify the functionality of our proposed circuits throughout this thesis.
We propose a new reference generation scheme, for a 1T-1C ferroelectric memory architecture, that is less sensitive to device imperfections of the ferroelectric capacitors. The proposed scheme uses reference current signal, instead of reference voltage, for higher linearity and accuracy.
We propose new architectures for both binary and multiple-valued Ferroelectric Content-Addressable Memories (FCAM). We provide detailed circuit-level designs for these architectures, and evaluate their performance by circuit simulations. The proposed multiple-valued architectures can be searched not only for a stored data item that is equal to the reference data, but also for stored data that is either greater-than or less-than the reference data. All proposed architectures offer nonvolatile storage with a real-time programming feature suitable for write-intensive applications.