Diffusion of arsenic along dislocations in epitaxial silicon films

A comparative study of zinc tracer diffusion profiles in LEC, SSD, and CVD GaP

“…With respect to our system, a t present a direct application of this conception is not possible because the effect of concentration-dependent bulk diffusivity generally has not been considered in the above-sketched theoretical model up to now. But our experimental results on GaP:Zn and also the curves presented in [2] (where a U,,(C) dependence exists which is qualitatively similar to Dzn(C) in Gap) show that the exponential dependence of the tail is a t least approximately maintained. Carrying out a Fisher analysis (i.e.…”

“…Further, clearly the level of the fast component correlates with the total length lgb of the grain boundaries/cm2 in the areas investigates (Zgb is nearly constant within the measured x-region). The value Cgb(l)/Cgb(2) = 1/2 approaches that of &b(l)/zgb (2). Lastly in Pig.…”

“…Further on, test experiments with ampoules consisting of a double chamber (the zinc atmosphere interacts with the GaP only after equilibration of the sample) demonstrate t h a t the C(z) structure is the same as after annealings in the simple conventional ampoules. Parameters: T = 850 "C, (1) t = 1.08 x 104s; (2) to ( 5 ) 70" ' t = 3 x 103s 0 10 40 60 80 I00…”

Fast Diffusion and Segregation along Threading Dislocations in Semiconductor Heterostructures

“…In the field of semiconductors, threading dislocations arising from the growth of thin films on dissimilar substrates limit device performance, their reliability, and ultimately their commercial viability. − The science of how dislocations impact properties has matured to the point where it is now imperative to fully characterize the types of atoms that are present at the dislocation. This realization stems from the fact that dislocations can support compositions or defect equilibria distinct from the rest of the crystal in a variety of materials, and simple models of dangling crystal bonds in an otherwise uniform lattice do not explain the observed electronic behavior. − Further, dislocations also act as fast diffusion paths in crystals , with recognized implications for silicon-based devices due to enhanced dopant diffusion. − This so-called “pipe diffusion” is usually studied as an enhancement in a spatially averaged bulk diffusion coefficient due to the presence of dislocations, − which does not capture the local inhomogeneity in composition. The local chemical environment of a dislocation in semiconductors not only affects its electronic properties − but also its mechanical properties like glide motion. , A modification of the dislocation glide properties due to segregates have implications for the ultimate dislocation densities and reliability in classes of dislocation containing devices such as III–V lasers. , …”