Formation and annealing of boron-oxygen defects in irradiated silicon and silicon-germanium n+–p structures

Abstract

New findings on the formation and annealing of interstitial boron-interstitial oxygen complex (B i O i ) in ptype silicon are presented. Different types of n+-p structures irradiated with electrons and alpha-particles have been used for DLTS and MCTS studies. Electronic excitation essentially changes the formation rate of B i O i . It has been found that the increase of oxygen content slows the B i O i annealing rate down. The activation energy of the B i O i dissociation has been determined and it was found that germanium doping does not change the activation energy.

Forward current enhanced elimination of the radiation induced boron-oxygen complex in silicon n+ -p diodes

“…) consistent with the results of Refs. . Thus, the presently reported FCE annealing procedure leads to a significant decrease in the activation energy for the annealing of the B i O i complex (Δ E a ∼1 eV), similar to the case of interstitial aluminum and boron in silicon .…”

“… to be E a = 1.2 eV. However, more recent studies reported slightly higher values E a = 1.35–1.4 eV. The annealing rate increases with the increase of the boron concentration and the decrease of oxygen content .…”

Electronic absorption of interstitial boron‐related defects in silicon

“…In the previous studies , it was shown by DLTS that the B i C s complexes in boron‐doped Cz‐Si arise synchronously with the dissociation of B i O i defects. The annealing temperature for B i O i , according to the studies is 150–200 °C, i.e., slightly higher than that for B i B s defects observed by us. Taking into account the closeness of these two annealing processes, it can be concluded that B i atoms liberated as a result of the dissociation of both B i B s and B i O i are involved in the formation of B i C s defects in the oxygen‐rich material.…”

“…The investigations of the boron‐related radiation defects in Si have been done in the main by deep level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR) . The main defect appearing in boron‐doped Si under the irradiation is known to be interstitial boron (B i ), which is created through the interaction of a self‐interstitial atom (I) with substitutional boron .…”

“…B i can be trapped by substitutional boron (B s ) and by the main impurities of Si such as oxygen and carbon with the formation of B i B s , B i O i , and B i C s complexes, respectively . The level at E c – 0.23 eV is ascribed to B i O i defect due to the correlation of its formation with the boron and oxygen concentrations in samples . The defect consisting of interstitial boron and oxygen was believed to be also responsible for the light‐induced degradation of Si solar cells .…”