Velocities of Screw and 60°‐Dislocations in Silicon

Abstract

The velocities of screw and 60"-dislocations in silicon have been measured for temperatures T between 580 and 800 "C and stresses t between 0.1 and 3 kp/mm2. The activation energy for the movement of 60°-dislocations &GO0 is stress-dependent in the whole stress range, that for screw dislocation Q, is constant f o r t 2 0.4 kp/mm2 and becomes also stress-dependent below 0.4 Irp/mm2. The current theories for kink motion do not yield a satisfactory description of the experimental results.Fur Temperaturen T zwischen 580 und 800 "C und Spannnngen t zwischen 0,l und 3 kp/mm2 wurden die Geschwindigkeiten von Schrauben-und 60°-Versetzungen in Silizium gemessen. Die Aktivierungsenergie fur die Bewegung von 60"-Versetzungen Qaoa ist spannungsabhangig im gesamten Spannungsbereich, fur Schraubenversetzungen ist &, konstant fur t 2 0,4 kp/mm2 und wird ebenfalls spannungsabhangig unterhalb von 0,4 kp/mm2. Die vorliegenden Theorien zur Kinkbewegung ergeben noch keine befriedigende Beschreibung der experimentellen Resultate.

The effect of annealing on residual stress and dislocation propagation in silicon slices with damaged layer induced by scribing

“…7). This is smaller than the mean value of dislocation movement calculated from the result obtained by George et al The fact that the stress reduction and the dislocation propagation were accomplished by annealing for 30 minutes at high temperatures can be explained by the large velocity of the dislocation movement measured by George et al [10]. Although the discussion on creep and the elastic/plastic transition was related to the well established mechanical behaviour of silicon by many researchers [9], this paper represents some new empirical results.…”

“…For the dislocation movement, George etal. measured the velocity of screw and 60~ in silicon for various temperatures and stresses [ 10]. The velocities measured ranged from 5 x 10 -6 772 cm sec -1 to 1.8 x 10 -4cm sec -1 at 700 ~ for example.…”

Non-Planar Slip and Cross-Slip at the Onset of Plastic Deformation in Silicon

“…Samples, 15 Â 4 Â 0.7 mm 3 in size, designed for tension testing [3] were cut from undoped FZ silicon. The tensile axis was chosen along [1 14], which corresponds to a double slip orientation but has the advantage that appreciable shear stresses are created on primary slip dislocations in their respective cross-slip planes, contrarily to the classical [123] orientation, which has zero Schmid factors on the cross-slip plane.…”

“…Further, some mechanisms must be found by which dislocations are not only multiplied in the initial slip plane but also in parallel planes, which were formally inactive. Repeated cross-slip has been invoked commonly for pole formation and transfer in new slip planes, but cross-slip remains poorly documented in Si, in spite of the observations by Mo È ller et al [2] or George and coworkers [3,4]. More generally, it is believed that any event by which a dislocation segment can escape from its slip plane might also help in triggering multiplication processes.…”

New Analysis of the Yield Point of Germanium

“…In all cases the test temperature was not higher than 600 C. In the same temperature range, Weiû [13] performed comprehensive creep experiments and, by analyzing the creep rate at the inflection point, also assumed U and 2 m to vary with stress and temperature, respectively. For the interpretation of his data he utilized a phenomenological modification of (2) proposed by one of us [14], which was originally introduced to explain measurements of the dislocation velocity of silicon,…”