In this work, the authors investigate analogue and radio-frequency (RF) figures-of-merit (FOM) of electrostatically-doped ferroelectric Schottky-barrier tunnel field-effect transistor (FET) (ED-FE-SBTFET) by deploying PZT (lead zirconium titanate) gate stack and dopant-free technology. This PZT gate stack results in negative capacitance behaviour as a result of the positive feedback among the electric dipoles within it. It realises an intrinsic amplifier to amplify the surface potential due to the applied gate bias and enhances the gate controllability significantly. As a result it facilitates lower ambipolar current, considerably high drive current and faster switching transitions. As the structure is realised by using dopant-free technique it ensures simplified fabrication process as it avoids the need of ion implantation and thermal annealing, reduces thermal budget. Here, a detailed comparison is carried-out between charge plasma Schottky-barrier tunnel FET and ED-FE-TFET for their high frequency FOMs such as cut-off frequency (), gain bandwidth product, transconductance generation factor and so on. The higher ratio of ED-FE-SBTFET reduces the static and dynamic both types of powers in digital circuits, while higher ratio ensures lower bias power of an amplifier.

The new azo-dye photoaligning films are robust and possess very good aligning properties for liquid crystal (LC) cells such as anchoring energies and voltage holding ratios as well as a high thermo and UV stability both in glass and plastic substrates with very high resolution on submicron level. The most important characteristics of azo-dye photoaligning films will be compared with those of rubbed polyimide films usually used for LC alignment. In this chapter, we will also describe the new applications of azo-dye photoalignment: (i) LC display devices, such as ferroelectric LCD for IPS, field sequential color and microdisplay applications; (ii) LC photonics devices, such as LC lenses; (iii) LC E-paper devices, such as electrically and optically rewritable LC E-paper; (iv) nanoscopic optically engineered polymeric thin film polarizers.

Operation of the 1-transistor, 1-capacitor dynamic random access memory cell that allows for two-bit operation, double the typical storage capacity, is explored. By using a metal-ferroelectric-semiconductor field-effect transistor, a second bit is captured in the ferroelectric layer polarisation resulting from negative and positive polarisation states. As a result, new modes of operation are created giving non-volatile, long-term storage as well as decreased power consumption and radiation hardening. A typical write and read operating cycle is outlined in-depth and used to verify operation indicating four distinct states representing the two bits. The resulting empirical data gives a comprehensive presentation of the read cycle of the memory cell. Methods for determining the polarisation state of the transistor are also explored and used to determine the average value for measured channel resistance using three types of transistors, each having different channel width and length.

A negative capacitance field-effect transistor (FET) with sub-60 mV/decade subthreshold slope (SS) at different temperatures (i.e. 14.8 mV/decade at 300 K, 15.7 mV/decade at 360 K and 24.3 mV/decade at 400 K) is experimentally demonstrated. A detailed account of the fabrication process of a negative capacitor is first introduced, followed by the measurement setup for the negative capacitance FET. The impact of temperature on negative capacitance FETs is investigated: (i) the equation for the internal voltage gain in the FET as a function of temperature is derived using Gibbs free energy and (ii) internal voltage against gate voltage (V _Int against V _G), internal voltage gain against gate voltage (dV _Int/dV _G against V _G) and drain current against gate voltage (I _D against V _G) curves at different temperatures are measured. It is confirmed that internal voltage amplification can be achieved using the ferroelectric capacitor. However, the magnitude of the step-up voltage transformation is reduced, i.e. from 9.5 at 300 K to 2.6 at 400 K. Additionally, the SS is slightly increased (i.e. degrading from 14.8 mV/decade at 300 K to 24.3 mV/decade at 400 K) with increasing temperature; however, all SS values are better than the physical limits of SS as dictated by Boltzmann statistics.

A frequency shifting device is fabricated and tested in a ferroelectric waveguide in a low-photorefractivity crystal. Periodic poling for quasi-phase-matching and channels for operation in the near-infrared C-band were obtained in congruent lithium tantalate, demonstrating for the first time both wave confinement and two-stage parametric conversion in such waveguides.

A novel design method for nonvolatile ferroelectric random access memory (FeRAM) using a merged bitline(BL)/plateline(PL) array architecture with a twin bitline-driven scheme is proposed. This method is effective in improving the FeRAM performance and reduces the power consumption. A 128 Kbit FeRAM prototype applying the proposed circuitry is implemented. The chip size, access time and memory array power dissipation are reduced to about 87, 44 and 15.8%, respectively, in comparison with those of conventional FeRAM.

A nonvolatile ferroelectric complementary metal-oxide-semiconductor (CMOS) circuit with both logic and memory functions is proposed as a new application of ferroelectric field effect transistors. The logic and memory operations of a NOT-logic ferroelectric CMOS device is demonstrated. Nondestructive readings of high and low output voltage levels of the device were performed. Data retention was measured up to10⁵ s (1.2 days).

A TRL-multiline de-embedding technique for the determination of the electrical parameters of interdigitated varactors over a broad centimetre–millimetre band is proposed. The method is applied to voltage-controlled ferroelectric (BaSrTiO₃) varactors, which exhibit almost constant frequency dependence of the capacitance (ɛ_r∼300) from 10 to 60 GHz. The capacitance ratio is ∼2 for a 30 V bias offset, and the quality factor is of the order 10 at 30 V.

Conditions for depositing perovskite-oriented Pb_0.92Sr_0.08(Zr_0.65Ti_0.35)O₃ thin films on gold by RF magnetron sputtering are investigated. Deposition results were analysed by scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffractometry. It was found that the desired perovskite phase can be obtained at a substrate temperature of 300°C, much lower than the typically reported 650°C for deposition on platinum.

The design and analysis of a new class of electric field-tunable ferrite-ferroelectric microwave bandpass filter is discussed. The tunability is possible through magnetoelectric interactions. When the composite is subjected to an electric field, the mechanical deformation due to piezoelectric effect manifests as a magnetic field shift in the ferromagnetic resonance for the ferrite. The electrical tuning is much faster than traditional magnetic tuning and has practically zero power consumption.