3 research outputs found
Effects of Excess Pb on Crystallization and Electrical Properties of Ferroelectric PZT Films Deposited by Reactive RF Magnetron Sputtering
No full textABSTRACTFilms were deposited onto unheated, Ti/Pt coated Si substrates by reactive sputtering in an argon-oxygen atmosphere from a sintered PZT target, and subsequently crystallized at temperatures between 550 and 650 °C. Pt/PZT/Pt capacitors were formed by ion beam sputtering of top electrodes through a shadow mask. Electrical properties were found to depend on gas pressure during deposition. This effect is interpreted in terms of variations in film stoichiometry (particularly Pb content). Films with large excesses of Pb were found to exhibit high leakage currents and poor ferroelectric behavior, whereas films with lower excesses of Pb had low leakage currents, and good ferroelectric properties. Films with the largest Pb excess had a random orientation, while the film with the lowest Pb excess had a preferred (111) orientation. With 550 °C crystallization temperatures the films consist of a mixture of ferroelectric perovskite phase and either PZT pyrochlore or PbO. At higher crystallization temperatures no pyrochlore is detected.</jats:p
Properties of Reactively Sputter Deposited SrTiO<sub>3</sub> Films for IR Detector Readout Electronics
No full textABSTRACTThe effects of film thickness, oxygen partial pressure, electrode type, substrate temperature, and position on the room temperature and 77 K dielectric properties of SrTiO3 (ST) films were studied. The film composition and properties vary with radial position and oxygen partial pressure. A maximum in dielectric constant occurs near the same position where stoichiometric films are obtained. The room temperature and 77K dielectric constants increase with increasing thickness, while the capacitance density decreases. Capacitance densities as high as 4 fF/μm2 were observed for films deposited at low temperature and subsequently crystallized. Elevated temperature deposition, however, results in better properties than room temperature deposition followed by annealing. Dielectric constants as high as 200 with capacitance densities up to 9 fF/μ2 were observed. For optimized deposition conditions, no dielectric break-down of the capacitors was observed at 20V after 111 days of testing. The properties of capacitors with n+Si bottom electrodes were not as good as those with Ti/Pt electrodes, however, integration with Si integrated circuit processing is expected to be much simpler.</jats:p
