摘要:

The defect formation in (100) Si at low temperatures during electron cyclotron resonance hydrogen plasma treatment has been studied. The temperature effect on crystalline defect morphology is studied by transmission electron microscopy and high resolution transmission electron microscopy. A high density of hydrogen-stabilized {111} platelets is observed at 240 °C, whereas a large number of amorphous {100} platelets is observed at 385 °C. The formation of amorphous {100} platelets without {111} platelets at 385 °C is reported. The amorphous {100} platelet at 385 °C results from the precipitation of oxygen promoted by hydrogen-enhanced oxygen diffusion. The low-temperature photoluminescence study and the spreading resistance profiles for the hydrogenated Si support the proposed mechanism of the amorphous {100} platelet. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.364098

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A study of end-of-range (EOR) dislocation loops in silicon implanted with 50 keV 1016Si/cm2was carried out by using transmission electron microscopy. Two kinds of post-implantation anneals were performed, furnace anneals at 850 °C and rapid thermal anneals at 1000 °C. We observed the ripening for two types of EOR dislocation loops. They were faulted Frank dislocation loops and perfect prismatic dislocation loops. By separating their size distribution profiles, we found that their distribution profiles are different from that of conventional Ostwald ripening for precipitates. A long tail distribution profile was formed for perfect prismatic dislocation loops. We analyzed the distribution profiles and found that the size distribution profile of faulted Frank dislocation loops could be well fitted by a normal Gaussian probability function and that of perfect prismatic dislocation loops by a log-normal Gaussian probability function. Measurement of the total number of interstitials within both types of loops shows that the ripening of EOR dislocation loops is conservative. Knowing the size-distribution profiles of the EOR dislocation loops, it was possible to perform an analysis of the ripening behavior of the two types of dislocation loops. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.364099

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A theory of the excitation of ultrasound waves arising from photoelastic coupling with light is presented in this article. Using several reasonable approximations, a numerical calculation of the transient stimulated Brillouin scattering process shows that a large amplitude of acoustic wave can be built up during the pulse of pump light, and it may result in damage to optical materials. This model gives a damage threshold value of ∼30–50 J/cm2when using Gaussian or square nanosecond pulses on optical materials. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.364100

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Based on the calculation of the survival probability, equations describing the kinetics of phase transformation with nucleation and growth mechanism are derived for general cases by including the temporal and spatial dependence both for the nucleation rate and for the growth rate. Particularly in this study, the crystallographic relationship in the growth is taken care of. For the simple case, in which the growth rate in the crystallographically identical directions are the same and the shape of grains remains congruent during the crystal growth, the influence of the shape factor on the kinetics can be determined for grains of different contours. The application to epitaxial growth yields the coverage quotient of a certain plane in the deposited crystals as a function of the reaction time and the position. Also the thickness distribution during the deposition can be determined. The exploration of the relationships between the growth kinetics and the crystallography is helpful to obtain reliable information about the mechanisms of nucleation and growth from the evaluation of the measurements. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.364101

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Thermodynamic properties of silicon (diamond cubic phase) are calculated using an empirical many-body potential developed by Tersoff [Phys. Rev. Lett.56, 632 (1986)] based on the concept of bond order. It is shown that this model gives predictions in good agreement with experiment for those properties governed by energetics (free energy, entropy, and heat capacity). The thermal expansion coefficient is less well described, which is traced to the fact that the model potential, in its present version, is overly stiff and therefore unable to account properly for the volume dependence of the transverse acoustic modes. Furthermore, sensitivity of the potential to whether each atom remains bonded to only four neighbors indicates that the short-range nature of the potential may necessitate model improvement before it is suitable for studies of thermomechanical properties at elevated temperatures or large deformations. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.364102

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Transient enhanced diffusion (TED) results from implantation damage creating enhanced diffusion of dopants in silicon. This phenomenon has mostly been studied using boron marker layers. We have performed an experiment using boron, phosphorus, and dislocation markers to compare TED effects. This experiment shows that phosphorus is enhanced significantly more than boron during damage annealing. Dislocation growth indicates that a number of interstitials greater than the damage dose is captured during these anneals. The time to saturate the dislocation growth agrees well with phosphorus diffusion saturation, and is greater than the boron saturation. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363994

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The interfaces of InP/InPAs(1 monolayer)/InP samples grown by organometallic vapor-phase epitaxy were investigated by the x-ray crystal truncation rod scattering measurement. The distribution of As atoms around the InPAs heterolayer was clearly revealed in the atomic scale from the measurement. It was shown that the distribution of As atoms into the layer under the InPAs layer was very small and that distribution of As atoms in the InP cap layer was, on the other hand, noticeable and the amount of As atoms was almost the same as that contained in the InPAs heterolayer. These results suggest that the extension of As atoms in the InP layer occurs due to the absorbed As atoms on the InPAs surface or As atoms remaining in the gas phase. Thus, to realize the abrupt InP/InPAs interface, the source-gas change sequence should be controlled to be very abrupt. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363995

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Mo¨ssbauer spectroscopy (57Fe) shows evidence for mixing effects induced by electronic energy deposition in nanoscale Fe/Si multilayers irradiated with swift heavy ions. A decrease in the mixing efficiency with electronic stopping power is reported; a threshold is found, under which iron environment modifications no longer occur. The kinetics of Fe–Si phase formation after irradiation suggests the existence of three regimes: (i) for high excitation levels, a magnetic amorphous phase is formed directly in the wake of the incoming ion and an almost complete mixing is reached at low fluence (1013U/cm2); (ii) for low excitation levels, a paramagnetic Si-rich amorphous phase is favored at the interface while crystalline iron subsists at high fluences; (iii) for intermediate excitation levels, saturation effects are observed and the formation rate of both magnetic and paramagnetic phases points to direct mixing in the ion wake but with a reduced track length in comparison to U irradiation. The measured interfacial mixing cross section induced by electronic energy deposition suggests that a thermal diffusion process is mainly involved in addition to damage creation. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363996

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The damage created in SiO2layers by low-energy Ar ions (130 keV) and the reconstruction of the structure after various annealing steps have been characterized as a function of the implantation dose. Quantitative determinations of the damage produced have been performed from infrared spectroscopy. We show that two dose thresholds for damage are encountered: At 1014cm−2damage saturates and for doses above 1017cm−2sputtering effects dominate. Annealing at high temperatures (1100 °C) restores the structure of the initial nonimplanted oxide only for doses below the second threshold, although some disorder remains. Electroluminescence measurements show that annealing is able to eliminate electrically active defects. For implantation doses greater than 1017cm−2, annealing is unable to restore the structure completely as sputtering effects create a depleted oxygen layer at the surface and substoichiometric defects appear. The presence of microcavities created by the Ar atoms at such high doses may affect the annealing behavior. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363998

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Cu (400 Å)/polyimide was mixed with 80 keV Ar+and N2+from 1.0×1015to 2.0×1016ions/cm2. The same processes were repeated for the Cu (400 Å)/Al (50 Å)/polyimide system which has Al as a buffer layer. The quantitative adhesion strength was measured by a standard scratch test. X-ray photoelectron spectroscopy was employed to investigate the change in the chemical bonds of the ion beam mixed polyimide substrate and the intermediate effects for the adhesion enhancement in Cu/Al/polyimide. Two distinct tendencies are observed in the adhesion strength: Cu/Al/polyimide is more adhesive than Cu/polyimide after ion beam mixing, and N2+ions are more effective in the adhesion enhancement than Ar+. The formation of an interlayer compound of CuAl2O4accounts for the former, while the latter is understood by the fact that N2+ions produce more pyridinelike moiety, amide group and tertiary amine moiety which are known as adhesion promoters. ©1997 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363999

出版商:AIP    

年代:1997

数据来源: AIP