Electrical activity of extended defects and gettering of metallic impurities in silicon

Advanced semiconductor diagnosis by multidimensional electron‐beam‐induced current technique

“…To overcome this drawback, several methods were developed to improve EBIC technique so far. In 1990s, the temperature dependence of EBIC contrast was analyzed in detail and the energy levels of dislocations were successfully deduced (see Pasemann, 1984;Kittler and Seifert, 1993;Kusanagi et al, 1995). Recently, we have developed EBIC technique to obtain more useful information about materials and devices.…”

Impurity Reaction with Dislocations in Semiconductors

“…Glide dislocations introduced by plastic deformation and Frank-type partial dislocations bounding extrinsic-type stacking faults formed around SiO 2 precipitates in Si both act as recombination centers for carriers and give rise to EBIC contrasts in the temperature range lower than about 200 K. However, they become recombination-inactive and their EBIC contrasts disappear at temperatures higher than 200 K if the crystal is not contaminated with metallic impurities [17]. These observations show that the energy levels of recombination centers associated with glide dislocations and Frank partials are shallow within the bandgap if they are not decorated with metallic impurities.…”

“…Both glide dislocations and Frank partials become EBIC-active at room temperature when they are decorated with metallic impurities [17]. This implies that deep levels are generated on these types of dislocations due to the decoration with such impurities.…”

Gettering Processes and the Role of Extended Defects

“…Further insight has been gained from experiments showing that the recombination activity of dislocations is strongly influenced by processing conditions and impurity contamination with in some cases very high rates of carrier recombination at dislocations [162][163][164][165][166][167][168]. In order to explain existing experimental data it was supposed that in addition to the 1D bands real dislocations could also have localized deep electronic states that may originate from intrinsic core defects like reconstruction defects and core defects caused by vacancies and self-interstitials incorporated into the dislocation core, or from impurity atoms in the dislocation core, in the strain field of dislocations or small impurity precipitates at dislocations.…”