Fabrication of Polycrystalline Ferroelectric Gate FET Memory with an Intermediate Electrode
We fabricated a new ferroelectric gate field-effect transistor memory (F-FET) with an intermediate electrode inserted between the ferroelectric capacitor (Cf) and the metal-oxide-semiconductor field-effect transistor (MOSFET) for writing data. The structure was a RuO2 top electrode/polycrystalline ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT)/(Pt/RuO2) intermediate electrode/SiO2/Si substrate. The basic operation of the new memory was confirmed by a discrete circuit that the Cf was connected serially with the MOSFET. For data writing, two positive or negative square pulses applied between the top electrode and the intermediate electrode induced the positive (Pr+) and the negative (Pr-) remanent polarizations, respectively, for coding memory states. For data reading, an unipolar square pulse train was applied between the top electrode and the source of the MOSFET, and the drain of the MOSFET was biased by a DC voltage. When the memory state corresponded to the Pr+ or the P-, the drain current (ID) was small or large, respectively. In this study, we used a polycrystalline PZT film to deal with the difficult problems of an epitaxial PZT film such as complicated techniques and high cost of products for commercialization goal.
Retention and Read Endurance Characteristics of a Ferroelectric Gate Field Effect Transistor Memory with an Intermediate Electrode
Fundamental characteristics such as retention and read endurance of a ferroelectric gate field effect transistor (F-FET) memory with an intermediate electrode were investigated and reported. It was verified that the retention time of the new F-FET was longer than 98 h. By taking into account the leakage currents of both the ferroelectric capacitor Cf and the MOSFET used for data writing (W-FET), we found that, for positive reading voltage, the leakage currents of the ferroelectric capacitor and the W-FET are unfavorable for the Pr+ state and the Pr- state, respectively, in terms of read endurance. The overall read endurance is determined by a competition between the leakage currents of the Cf and the W-FET. The drain-connected configuration (DCC) was effective to minimize the unexpected influence of the leakage current of the W-FET.
The lights that failed: European international history, 1919-1933
PART I: THE RECONSTRUCTION OF EUROPE, 1918-1929 1. The Hall of Mirrors: Peacemaking in the West 2. Distant Frontiers: Peacemaking in the East 3. Revolution from the Left: The Soviet Union and the Post-War Settlement 4. The Primacy of Economics: Reconstruction in Western Europe, 1919-1924 5. The Primacy of Nationalism: Reconstruction in Eastern and Central Europe 6. Revolution from the Right: Italy, 1919-25 7. The Geneva Dream: The League of Nations and Post-War Internationalism 8. New Dawn? Stabilisation in Western Europe after Locarno 9. Faltering Reconstruction: Cracks in the Locarno Facade 10. Troubled Waters: Uncertainties in Italy, Eastern Europe and the Soviet Union 11. Faltering Internationalism: Disarmament and Security after Locarno Conclusion: Europe Reconstructed? PART II: THE HINGE YEARS, 1930-1933 12. The Diplomacy of the Depression: Economics and Foreign Policy 13. Beyond Europe: The Manchurian Crisis 14. The Poisoned Chalice: The Pursuit of Disarmament Conclusion: The Hinge Years Appendices Select Bibliography