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Selective area growth was adopted to grow high-quality quantum dots (QDs) of different energy levels on the same plane at 1.5 μm. At room temperature, the photoluminescence (PL) peak of InAs/InGaAsP QDs on InP substrate was shifted from 1445 to 1570 nm for sample 1 (from 1385 to 1485 nm for sample 2) in a plane, with a PL intensity comparable to those of regular samples grown without dielectric patterns. The dot shape was a round dome, with the density reduced by 28% and the height increased by 17%. Time-resolved PL indicated that the selectively grown QDs behaved similarly to regular QDs. These results open up a practical method for in-plane integration of QD devices. [ABSTRACT FROM AUTHOR]

The electromigration behavior of Sn–2.5Ag and Sn–0.7Cu (in wt %) flip chip solder joints on electroless NiP/Cu metallization at a current density of 1.3×104 A/cm2 was studied. For Sn-2.5 Ag solder, electromigration at 115 °C for 250 h showed a selective dissolution of Ni from the electroless NiP layer forming crystallized Ni3P. At 140 °C, the damage to the NiP layer was accelerated and instability of the NiP/Cu interface was observed. For eutectic Sn–0.7Cu solder, the electromigration behavior at a higher temperature was evaluated. At 180 °C, the NiP/Cu under bump metallurgy (UBM) started to show damage after 50 h. At 200 °C, the entire NiP/Cu layer was damaged, and P in the NiP layer moved to the edge of the anode much faster than the other species forming CuP2 intermetallics. NiP/Cu UBM experiences selective dissolution of Ni at lower temperatures, and the damage of the entire UBM occurred abruptly at the higher temperature. [ABSTRACT FROM AUTHOR]

The reaction kinetics of eutectic SnPb solder on Cu were studied and compared in the liquid state at 200 to 240 °C and in the solid state aged at 125-170 °C. The ternary phase diagrams of SnPbCu, the morphology of intermetallic compound (IMC), and the kinetics of growth of the intermetallics were used in the comparison. The temperature difference between these two reactions is only 30 °C, but the kinetics of reaction, as well as the morphology of IMC formation, are very different. The kinetics in the wetting reaction is four orders of magnitude faster than that in solid state aging. The Cu[sub 6]Sn[sub 5] intermetallic morphology in solid state aging is a layer type, but it has a scallop-type morphology in the wetting reaction. The morphology strongly affects the kinetics. While the kinetic difference can be attributed to the difference in atomic diffusivity between the liquid state and the solid state, it is the morphology that determines the kinetic path in these reactions. We conclude that a fast rate of reaction, which leads to a high rate of Gibbs free energy change, controls the reaction, not the Gibbs free energy change itself. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The morphology of interfacial reaction products between four lead-free solder alloys on electroless Ni-P was characterized. The four Pb-free solders were 99.3Sn0.7Cu, 95.5Sn3.8Ag0.7Cu, 96.5Sn3.5Ag, and 96Sn2Ag2Bi (in wt%) alloys. After reflow, the interfacial intermetallics in the first two solders that contain Cu (99.3Sn0.7Cu and 95.5Sn3.8Ag0.7Cu) had good adhesion with electroless Ni-P. However, the 96.5Sn3.5Ag and 96Sn2Ag2Bi alloys formed interfacial intermetallics with a needle shaped morphology that spalled off the surface of electroless Ni-P. This difference is attributed to the role of Cu in the solders (which modified the chemical potential of the interfacial intermetallics), the volume change that occurs during intermetallic formation, and the interfacial properties of the compound. In solid state aging experiments, the consumption of electroless Ni-P by intermetallic growth was not significant (approximately 1 μm) and all the intermetallics had good adhesion to the electroless Ni-P. The electroless Ni-P exhibited some damage at the outer edge of the bond pad due to stress imposed during solid state aging. Large Ag[sub 3]Sn and Cu[sub 6]Sn[sub 5] intermetallics were observed in the bulk of the solders (except for SnAgBi solder), and these intermetallics are discussed in terms of soldering reaction at the interface and phase equilibrium. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents information on a study on the wetting behaviors and interfacial reaction of the eutectic metal compound SnPb. Wetting behaviors of eutectic SnPb on Ni foils; Interfacial reaction between eutectic SnPb and Ni foils; Interfacial reaction between eutectic SnPb and Ni foils and the consumption rate of Ni; Dewetting on Ni/Ti thin films.

Presents information on a study which focused on the kinetic analysis of interfacial diffusion accompanied by intermetallic compound formation. Mathematical analysis; Experimental results and discussion.

Presents information on a study which analyzed solder reaction-assisted crystallization of electroless Ni-P under bump metallization in the multilayer structure using transmission electron microanalyzer. Research background; Experiment; Results and discussion; Conclusions.