The effect of thin Ti/PbZr0.4Ti0.6O3 seed layers on the properties of PbZr0.4Ti0.6O3 (PZT) capacitors has been investigated. The seed layer is based on a bi-layer of thin Ti and thin PZT with a total thickness ranging from 10 to 25 nm, which was deposited on Ir/Pt or Ir/IrO2/Pt by sputtering. After crystallization of the seed layers the main 130-nm-thick PZT film was deposited and crystallized. As a result, a highly preferred (111)-orientation of the PZT was obtained on a 10-nm-thick seed layer, where the peak intensity ratios of (111)/{100} and (111)/{110} are about 100 and 20, respectively. The 10-nm-thick seed forms a pyrochlore phase with a very smooth surface, where the formation of the pyrochlore phase is attributed to Pb diffusion, resulting in a Pb deficient stoichiometry. The seed layer transformed to the perovskite phase during the main PZT crystallization. It is shown that an IrO2 layer beneath the Pt can prevent Pt layer degradation related to the volume expansion due to the oxidation of Ir during the main PZT crystallization. Capacitors with the 10-nm-thick seed layer fabricated on the Ir/Pt and Ir/IrO2/Pt substrates showed typical 2 Pr values of 44.0 μC/cm2 and 41.2 μC/cm2, respectively. The voltage found for 90%-polarization saturation is about 3.0 V, and the capacitors are fatigue-free at least up to 1010 switching cycles.

For high density FeRAM devices small cell sizes are essential. The combination of the capacitor on plug (COP) structure with the Chain FeRAM™ cell design is used to develop a 32Mb FeRAM. Based on a 0.2 μm standard CMOS process a silicide capped polysilicon plug is used to contact the bottom electrode of the ferroelectric capacitor to the transistor. The barrier contact to the plug is formed by IrO2/Ir and a sputter deposited PZT (40/60) is used as ferroelectric material. The function of SrRuO3 (SRO) layers at the electrode/PZT interfaces is described in more detail. Double sided SRO results in slightly lower coercive voltage and imprint behavior compared to capacitors without SRO. Double sided SRO is essential to achieve excellent fatigue behavior measured up to 1×1011 switching cycles.

In many fiber reinforced composite systems, protective coatings on the fibers are required in order to protect the fiber from reaction with the matrix, to modify the mechanical properties of the fiber-matrix interface, or to protect the fiber during processing steps such as chemical vapor infiltration. We have developed techniques for coating single crystal sapphire fibers with thin AIN layers, using CVD from an organometallic precursor in a cold wall reactor. Side by side tests of coated and uncoated fibers introduced into a MoSi2 matrix, either by hot isostatic pressing or by reactive vapor infiltration (RVI), indicate that the coating inhibits both fibermatrix interdiffusion and volatilization of the fibers by HC1 produced in the RVI process.

Reactive Vapor Infiltration is a convenient new process for producing high purity MoSi2 matrix composites by reacting compacted mixed Mo + MoSi2 powders ranging from 0 to 80 wt. % MoSi2 with H2 + SiCl4 vapors at temperatures from 1000 to 1400°C. Consideration must be taken of the volumetric increase that accompanies this conversion. The kinetics of the advance of the MoSi2 growth layer and the gravimetric uptake are given as a function of temperature and the composition. The parabolic growth rate constant was independent of composition at least up to 30% MoSi2 composition, but then showed a strong, linear increase with increasing MoSi2 content. There appeared to be a levelling off of rate above 70% MoSi2. The corresponding gravimetric rate constant was relatively insensitive to the starting MoSi2 content. This behavior is at variance with a simple one-dimensional diffusive growth model. Possible reasons for this variance are offered.

Aluminum nitride films were deposited on Si (100) and sapphire (1102) substrates by low pressure chemical vapor deposition using the metalorganic precursor trisdimethylaluminum amide, [(CH3)2AlNH2]3. Depositions were carried out in a cold wall reactor with substrate temperatures between 500 and 700 °C and precursor temperatures between 50 and 80 °C. The films were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy. The films were generally smooth and adherent with colors ranging from transparent to opaque grey. Cracking and spallation were seen to occur at high film thickness. Deposition rates ranged from 20 to 300 Å/min and increased with both precursor and substrate temperature. Carbon concentrations were small, < 5 at. %, while oxygen concentrations were higher and showed a characteristic profile versus depth in the film. High temperature compatibility testing with sapphire/AlN/MoSi2 samples was carried out to determine film effectiveness as a fiber coating in a composite.

Three different methods of preparing Mosi2 and composites reinforced with ceramic fibers by reactive in-situ processing are described. Reactive powder sintering (co-synthesis) of elemental powders, chemical vapor infiltration/deposition and reactive vapor infiltration are examined. Monolithic Mosi2, SiC particle-reinforced Mosi2 or fibrous Mosi2 composites reinforced with Nicalon fiber were prepared. The advantages and disadvantages of these processes relative to more traditional processing techniques such as HIPing of prealloyed powders, mechanical alloying and a reported in-situ displacement reactions are discussed.

Noise and haste brand our times….’ No novel statement, this: we have all heard it in some form or other, and most people, at least in the Western world, surely agree. We are slaves—the very watch on our wrist a sign of servitude—we have ‘no time', ‘no rest'; ‘Angina Temporis’ (as Dr Bramesfeld terms it) is a common disease. It is a fact that, even if a few free days do come our way, we are no longer caplable of relaxing; restless activity holds us entirely in its power. Man, his nerves tense and his mind fuddled, finds no shelter of peace awaiting him when he is ejected nightly from office or factory; wearily he reaches home, only to plunge himself into so-called amusements. His money is taken from him and in return he becomes momentarily intoxicated with unhealthy, forced excitment, but there is neither peace nor lasting satisfaction in it.