Temperature dependence of electron beam induced current contrast of deformation-induced defects in silicon

Abstract

Electron beam induced current (EBIC) investigations of plastically deformed silicon in the temperature range from 90 K to 300 K were carried out. It is found that the dislocation trails left behind moving dislocations are the main defects revealed by the EBIC in crystals deformed in clean conditions. With an increase of the contamination level, the dislocation contrast in p-type samples increases. It is observed that the EBIC contrasts of both dislocations and dislocation trails increase with cooling in p-type silicon, while in n-type samples the EBIC contrasts exhibit the opposite trends for both defects.

EBIC characterization of strained Si/SiGe heterostructures

“…The role of such defects could play dislocation trails, i. e. some specific defects formed behind moving dislocations in the dislocation slip planes. Indeed, such defects provide the noticeable EBIC contrast even in Si deformed in clean conditions, when the dislocation contrast is below the detectivity limit [13,14]. These defects could be revealed by chemical etching [15].…”

“…At low beam energy the contrast inside the depletion region was observed [10,11], which was ascribed to misfit dislocations near strained Si/SiGe interface. However, recent investigations of individual dislo- ¶ E-mail: yakimov@ipmt-hpm.ac.ru cations in clean Si wafers [12][13][14] showed that their EBIC contrast was negligible. In the same time the electrically active defects can be formed behind moving dislocations (dislocation trails), which could produce the rather strong EBIC contrast even in clean crystals [13][14][15].…”

“…However, recent investigations of individual dislo- ¶ E-mail: yakimov@ipmt-hpm.ac.ru cations in clean Si wafers [12][13][14] showed that their EBIC contrast was negligible. In the same time the electrically active defects can be formed behind moving dislocations (dislocation trails), which could produce the rather strong EBIC contrast even in clean crystals [13][14][15]. Therefore, the question about the nature of EBIC contrast observed in Si/SiGe heterostructures seems to be not totally closed.…”

Is there an impact of threading dislocations on the characteristics of devices fabricated in strained‐Ge substrates?

“…4 and 5. Such asymmetry in the dislocation electrical activity has been noted before in Electron Beam Induced Current (EBIC) studies [35]. This can be explained on the one hand by the predominant acceptor-like nature of the TD-induced deep levels in the SiGe buffers and by the fact that in n-type material, a barrier builds up around the dislocation line when it becomes progressively filled up with electrons.…”

“…One of the ideas gaining more and more popularity is that the glide of TDs in relaxed SiGe layers leaves behind a trail of point defects in the glide plane [27,28,35,36], for example by the non-conservative dragging of jogs in the dislocation structure. Positron annihilitation has shown the presence of open volume defects in plastically deformed semiconductors [36], pointing to the presence of vacancy clusters.…”