Hf-silicate films were deposited directly onto n-type Si (100) substrates and Pt-coated Si substrates by a pulsed laser deposition technique using a ceramic Hf-silicate target. The thermal stability and electrical properties of Hf-silicate films have been investigated by x-ray diffraction, differential thermal analysis, atom force microscopy, x-ray photoelectron spectroscopy, capacitance-voltage (C-V) and leakage current-voltage (I-V) measurements. The amorphous structure of Hf-silicate films was found to be stable up to at least 900℃. A crystallization transformation from the amorphous phase to a polycrystalline tetragonal structure occurs under rapid thermal annealing for 3min at 1000℃. The amorphous Hf-silicate film exhibits a high dielectric constant of about 14.1 measured in a Pt/Hf-silicate/Pt capacitor structure. The smoothness and electrical properties of films have been improved by rapid thermal annealing in N2 ambient at 900℃ for 30s. A very small equivalent oxide thickness of 0.95nm for 2.6nm Hf-silicate film on the n-Si substrate and a low leakage current of 24mAcm−2 at 1V gate voltage were obtained. Thus, Hf-silicate films with good thermal stability can be one of the most promising candidates for future high-k gate dielectric applications.

SrBi2Ta2O9 thin films were prepared by pulsed laser deposition at different substrate temperatures. Photoluminescence (PL) has been detected at room temperature from the pyrochlore phase in the SrBi2Ta2O9 film deposited at 850℃. The PL shows five luminescence bands of 330, 365, 407, 490,and 600nm. And the PL excitation shows six excitation bands of 278, 330, 365, 407, 490, and 600nm. The one-to-one correspondence of PL and PL excitation spectra reveals a band-to-band excitation and a multienergy-gap structure in the pyrochlore phase in SrBi2Ta2O9 films.

Pt/PbZr0.53Ti0.47O3 (PZT)/LaA1O3 (LAO)/Si and Pt/PbZr0.53Ti0.47O3/La0.85gr0.15CoO3 (LNCO)/LaAIO3/Ni structures forfen-oelectlic field effect memory applications were fabricated on n type Si substrate by pnlsed laser deposition (PLD). TheAnger electron spectrometry (AES) analysis shows that a LaAlO3 bnffer layer can effectively prevent Si and Ti, Pb int erdiffnsionbetween PZT and Si snbstrate. For both of the structure, the current density voltage measnrement shows a typical leakagecurrent density of about 10 7A/cm2 at 8V applied voltage. Furthermore, it has been demonstrated that the PbZro 53Ti04703/LaAlO/Si structures and Pt/PbZr0.53Ti0.4703/Lao85gro15CoO3[LaA103]gi structures exhibit felroelectric switching properties,showing a memory window as large as 2 and 2.9V, respectively, raider a ramp rate of 200mV/s from 6 to +6V driving voltageat lMHz. it is believed that the Lao ssSr0.15 CoO3 bufffer layer deposited on LaA103 layer can improve the crystalline propertiesof PZT fihns, and then resnlt in lager polarization of PZT and lager memory windows for Pt/PbZros3Tio 4703/La085Sr015C003/LaAlO/Si structures.

Amorphous LaAlO3 (LAO) and LAOxNy (LAON) films have been prepared by pulsed laser deposition technique on Si (100) substrates and Pt coated silicon substrates. X-ray diffraction, transmission electron microscopy and differential thermal analysis investigations showed that both kinds of films remain amorphous up to a high temperature of 860℃. Atomic force microscopy study indicated that the surface of the deposited films is very smooth with a root mean square roughness of 0.14nm for 8nm LAO. LAON films have a smoother surface than that of LAO films. High-resolution transmission electron microscope studies showed there often exists interfacial reaction between LAO and Si. One LAON/Si structure nearly without interfacial layer has been obtained. For LAO films, high bandgap of 6.55eV and medium dielectric constant of 25-27 have been obtained. The LAON films showed small equivalent oxide thickness of 1.1nm with a low leakage of 0.074A/cm2@Vg511V. It is proposed that amorphous LAON films are very promising dielectric materials for high k gate dielectric applications.

The morphology, microstructure and composition of the precipitates produced in the decomposition of a Ni-12 at.% Be alloy aged at 843K for several hours have been characterized by tomographic atom probe (TAP), field ion microscopy (FIM) and transmission electron microscopy (TEM). The precipitates are thin, plate shaped and nearly stoichiometric -NiBe with B2 structure. In the samples aged for 5-7h most of the -plates have a thickness of the order of 1nm and an aspect ratio of about 10. The habit plane of the -plates is mainly observed to be parallel to the (001) plane of the matrix. However, some of the -plates show a considerable deviation from this orientation relationship. The interfaces between precipitates and matrix are both structurally and compositionally very sharp. The observed morphology is explained in terms of the strong anisotropy of the interfacial energy, the elastic energy set up during the precipitation, and the ledges at the interfaces.