Volume 96, Issue 5, 01 September 2004
Index of content:
96(2004); http://dx.doi.org/10.1063/1.1775042View Description Hide Description
Assisted by ab initio calculation, an -body potential is derived for the equilibrium immiscible Cu–Nb system. Based on the potential, molecular dynamics simulations reveal that among the nine interfaces stacked by possible combinations of (100), (110), and (111) atomic planes, only the and interfaces could remain stable up to a temperature of , and that introducing a disordered interlayer at these two interfaces could trigger solid-state amorphization, suggesting that the close-packed plane does not serve as a growth barrier, which was frequently the case observed previously in many other systems.
96(2004); http://dx.doi.org/10.1063/1.1774256View Description Hide Description
Some heterostructures with different high electron mobilities were electrically characterized as a function of temperature. Hall measurements were made at and current-voltage characteristics were measured from . Experimental results have revealed a saturation of the current at electric fields as low as at low temperature . The saturation was linked to the very high mobility combined with the presence of alloy diffusion in the channel. The pinch-off effect was excluded because of the absence of the control gate. Drift velocities were carried out at in these experiments.
Time-resolved photoluminescence and capacitance–voltage analysis of the neutral vacancy defect in silicon implanted on silicon substrate96(2004); http://dx.doi.org/10.1063/1.1775041View Description Hide Description
The nanosecond photoluminescence(PL) dynamics of neutral oxygen vacancy (NOV) defects at , and less pronounced nanocrystallite Si precursor defects at in multi-energy silicon-ion-implanted are investigated. The density of NOV defects in as-implanted of (or calculated from time-resolvedPL) is determined by using capacitance-voltage measurement. After annealing at for , the NOV defects are completely activated with a concentration of and a corresponding absorption cross section of . The time-resolvedPL lifetime of NOV defects in is significantly shortened from and these defects are fully activated after annealing for . Longer annealing time greatly attenuates the blue-green PL intensity and eliminates the NOV defects, whereas the PL intensity and concentration of defects with lifetime of increases by a factor of 2.
96(2004); http://dx.doi.org/10.1063/1.1777392View Description Hide Description
Nonequilibrium, atmospheric pressuredischarges are rapidly becoming an important technological component in material processing applications. Amongst their attractive features is the ability to achieve enhanced gas phase chemistry without the need for elevated gas temperatures. To further enhance the plasma chemistry, pulsed operation with pulse widths in the nanoseconds range has been suggested. We report on a specially designed, dielectric barrier discharge based diffuse pulsed discharge and its electrical characteristics. Two current pulses corresponding to two consecutive discharges are generated per voltage pulse. The second discharge, which occurs at the falling edge of the voltage pulse, is induced by the charges stored on the electrodedielectric during the initial discharge. Therefore, the power supplied to ignite the first discharge is partly stored to later ignite a second discharge when the applied voltage decays. This process ultimately leads to a much improved power transfer to the plasma.
Effect of oxygen precipitates and induced dislocations on oxidation-induced stacking faults in nitrogen-doped Czochralski silicon96(2004); http://dx.doi.org/10.1063/1.1777804View Description Hide Description
The effect of oxygen precipitates and induced dislocations on oxidation-induced stacking faults (OSFs) in nitrogen-doped Czochralski (NCZ) silicon has been investigated. Both CZ and NCZ wafers were annealed at and for with or without a post-treatment at for , and then were totally oxidized at . It was found that after oxidization, few OSFs generated in the NCZ silicon subjected to the annealing at 800 and , while larger numbers of OSFs in the CZ silicon. However, if the post-treatment at was employed prior to oxidization, OSFs density in the NCZ silicon was almost similar to that in the CZ silicon. It is considered that the high density of oxygen precipitates and induced dislocations formed in NCZ silicon can absorb the self-interstitial silicon atoms so that the generation of OSFs is inhibited. After the postannealing, most dislocations shrank and dissolved with the dissolution of oxygen precipitates in the NCZ silicon so as to induce the same amount of OSFs as that in the CZ silicon.