To increase the density of memory devices, it is necessary to reduce the cell size. However, the smaller capacitors are made, the more difficult it becomes to measure their characteristics. Analysis of the electrical characteristics of single-bit cell capacitors has therefore increased in importance. We have developed a new method of analyzing memory devices using a multi-probe atomic force microscope (AFM) to overcome the limitations of a single-probe AFM. There can be up to five probes in this system. Fast square pulses with a rise time in nanoseconds are used to obtain the switchable polarization of the single-bit cell capacitor. Two separate probes individually contact the top electrode and the bottom electrode to apply the fast pulse. As a result, high-speed pulse measurements with up to a 50-ns pulse width and a 6-ns rise time have been achieved with an actual single-bit cell capacitor. This multi-probe AFM system could thus become a standard industry tool for device testing, such as for high-speed pulse measurements.

No abstract

No abstract

We investigated the crystallization mechanisms of sputter-deposited La-doped Pb(Zr,Ti)O3 (PLZT) on a Pt/Ti metal stack in the postdeposition annealing (PDA) at 600 °C in O2-mixed Ar ambient. As-deposited amorphous PLZT generally transforms to a perovskite phase over 550 °C through a metastable pyrochlore phase during the PDA. We found that the O2 content of the PDA ambient crucially affects the pyrochlore-perovskite transformation (PPT) speed. While an O2 content much higher than 2% of the PDA ambient suppresses PPT, an O2 content much lower than 2% enhances PPT. An O2 content around of 2% of the PDA suppresses PPT near the surface of PLZT and simultaneously keeps PPT fast in the inner regions of PLZT in the pyrochlore phase because of the O2 diffusion limit from the PLZT surface, eventually resulting in almost only the growth of highly {111} oriented columnar PLZT on Pt, which reveals better electric properties than those obtained by the PDA with the ambient of O2 contents much higher or lower than 2%.

We take steps toward constructing explicit solutions that describe nonextremal charged dilatonic branes of string/M-theory with a transverse circle. Using a new coordinate system we find an ansatz for the solutions with only one unknown function. We show that this function is independent of the charge and our ansatz can therefore also be used to construct neutral black holes on cylinders and near-extremal charged dilatonic branes with a transverse circle. For sufficiently large mass M > M c these solutions have a horizon that connects across the cylinder but they are not translationally invariant along the circle direction. We argue that the neutral solution has larger entropy than the neutral black string for any given mass. This means that for M > M c the neutral black string can gain entropy by redistributing its mass to a solution that breaks translational invariance along the circle, despite the fact that it is classically stable. We furthermore explain how our construction can be used to study the thermodynamics of Little String Theory.