We studied the correlation of in and ex situ stress to microstructures during Al-induced crystallization for structures of Al on top (AOT) and Al on bottom (AOB) of amorphous Si (a-Si) on 3000 Å SiO2 coated on Si wafers and found that a-Si deposited on PECVD SiO2 and Al increases the stress compressively, and Al deposited on PECVD SiO2 and on a-Si decreases the stress tensilely. In addition, the stress of AOB structures is in general less than that of AOT structures. Correlation of stress to microstructures indicated that the difference in microstructures between AOT and AOB results from the nature of the layer structures themselves. By using modified Stoney's equation, the lower stress of AOB structures than AOT could be explained with existence of oxide between a-Si and Al for both AOT and AOB structures.

We have used electrical characterization and secondary ion mass spectroscopy (SIMS) to investigate the influence of hydrogen or deuterium (H/D) on the degradation of the electrical properties of metal/Ba0.7Sr0.3TiO3/metal (M/BSTO/M) thin film capacitors after forming gas annealing (FGA). Leakage and dielectric relaxation currents increase after FGA at temperatures as low as 23C. SIMS profiling shows that at 23C H/D diffuses through thin film metal electrodes and accumulates at electrode interfaces. The location (top or bottom electrode interface) of H/D accumulation is dependent on the type of electrodes and capacitor structure. The resulting asymmetric distribution of H/D leads to large voltage offsets in the C-V characteristic, asymmetric leakage currents, and increased dielectric relaxation currents. Possible mechanisms for increased leakage and relaxation currents after FGA are discussed.

We have investigated the molecular beam epitaxy (MBE) growth of buried InAs quantum dots on GaAs (001) surface, as a function of deposition temperature, by transmission electron microscopy (TEM) and photoluminescence (PL). We found that the dot growth at low temperature is controlled by diffusion-limited aggregation. As the growth temperature increases, this growth mode is modified by misfit strain, resulting in a narrowing of the size distribution. However, we did not find any evidence for a thermodynamically optimized size. In addition, we found that the optical properties of the quantum dots does not correlate directly with the geometric size of the quantum dots, indicating a complex internal structure for quantum dots grown at high growth temperature.