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The dynamic properties of dislocations in nitrogen (N)-doped Czochralski-grown Si crystals with various concentrations up to 6 x 10(super 15) cm(super -3) are investigated using the etch pit technique and compared with such characteristics of N-free Si crystals. The findings revealed that N doping is effective in the promotion of precipitation of oxygen impurity resulting in immobilization of dislocations.

Research describing the dynamic characteristics of dislocations within silicon crystals doped with boron is presented. The etch pit technique is used to investigate the effects of varying boron concentrations.

We report diffusion experiments of Au in highly dislocated, undoped and homogeneously doped Si with B concentrations of 3.0×1019 and 1.7×1020 cm-3. After Au diffusion at temperatures between 800 and 1100 °C, Au profiles were measured by means of neutron-activation analysis in conjunction with serial sectioning. The diffusion of Au in dislocated Si is accurately described on the basis of the kick-out mechanism and an additional reaction which takes into account the capture of interstitial Au at dislocations. The profiles yield data for the boundary concentration CAu0 and the Au diffusion coefficient DAu whose product CAu0DAu equals the transport capacity CAuieqDAui of interstitial Aui. With increasing B doping Au diffusion increases showing that interstitial Au is singly positively charged. An enhanced boundary concentration CAu0 and simultaneously retarded Au diffusivity was observed at temperatures below 1000 °C which provides direct evidence of Au segregation at dislocations. A segregation enthalpy of 2.7 eV for the energy difference of Au atoms dissolved on substitutional lattice sites and Au atoms trapped at dislocations was determined. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Several modeling studies are conducted to explain the properties exhibited by the different intrinsic, as well as oxygen-contaminated silicon nanocrystals. The fraction of the effectively mobile dislocations is shown to highly decay with the unlocking stress.

The article presents a complete analysis of the crystallinity and optical and electrical properties of the various N and Te codoped Zn-polar ZnO films that are grown by the plasma-assisted molecular-beam epitaxy. The crystallinity of the films is shown to significantly enhance with the N and Te codoping.

The variation in stacking fault energy with annealing at 1173 K is identified in Czochralski-grown silicon crystals heavily doped with n- or p-type dopant atoms. The results have shown that n-type dopant atoms segregate nearby a stacking fault through their thermal migration under an electronic interaction leading to a reduction in the stacking faulty energy.

An improved constitutive model for intrinsic silicon monocrystals deformed in single slip is described. The parameters for the slip systems identified as analytical functions of temperature is found to be in an excellent agreement with the observed steady state of deformation in stage I.

Optical properties of wurzite ZnO bulk single crystals in which an arbitrary number of fresh dislocations are introduced by the plastic deformation at elevated temperature are examined. The introduction of the dislocations at the elevated temperatures above 923 K has not affected the intensities of the emission bands except the dislocation-related emission bands.

The compressive deformation analysis is employed to study the high-temperature mechanical strength and dislocation mobility of the wide band-gap ZnO crystal. The yield stress and the activation energy for dislocation motion in the crystal are shown to be highly dependent on the temperature.

Preliminary results of carrier mobility in the heavily impured Si(sub x)Ge(sub (1-x)) single crystals with the composition 0.84(less than) x (less than)1 in the temperature range from RT to 1000 K are presented. The hole mobility tends to increase with decreasing Si content to 0.84 while the electron mobility in the Si-rich SiGe single crystals is greater than in Si and polycrystalline SiGe.

The characteristic of the dislocations in the ZnO layers grown on c sapphire by the plasma-assisted molecular beam epitaxy under the different Zn/O flux ratios is investigated. The ZnO layers were characterized by the transmission electron microscopy (TEM) and the high-resolution X-ray diffraction (HRXRD).

The dynamic behavior of dislocation in heavily Ge-doped Si crystals and Ge and B codoped Si crystal has been investigated which demonstrates strong suppression of dislocation generation in Si codoped with Ge and B, while weak suppression occurs in Ge-doped Si and the critical stress increases gradually with increasing Ge concentration. This is interpreted in terms of dislocation immobilization due to the effective segregation of both Ge and B impurities.

There are three different types of dislocation in II-V compound semiconductor crystal, alpha, Beta and screw. The dynamic behaviour of dislocations in InAs has been investigated using the etch-pit technique. The dislocation velocity was compared with other III-V compound semiconductors. Alpha dislocations were found to move faster than beta dislocations in undoped and impurity-doped InAs.