Oxygen Effect on Electrical and Optical Properties of Dislocations in Silicon

Intrinsic Defects and the D1 to D4 Optical Bands Detected in Plastically Deformed Si

“…The main evidence for the assignment comes from the calculated local vibrational modes which are close to a phonon replica found at 564 cm −1 . This undergoes large isotopic shifts with 29 Si and 30 Si. These imply that the vibration is due to a compressed Si-Si bond lying on the trigonal axis so that the vibrational mode lies above the Raman and is localised on one or two Si atoms.…”

“…They are seen in both Cz and FZ material irrespective of type, and are stable to 1000 • C. They exhibit strong polarisation along the dislocation line direction 28 . D1 and D2 are initially enhanced by oxygen 29,30 and low concentration of transition metal impurities such as Cu 31,32 . However, larger concentrations of Cu suppress the bands.…”

Dislocation Related Photoluminescence in Silicon

“…In most cases there are both filled and empty levels in- activity of the dislocation with the appearance of occupied states low in the gap, similar to those of the isolated I 3 and I 4 defects, and unoccupied levels in the upper quarter. These states could account for the broad band seen in DLTS studies [15] and the 0.83 eV D b PL band linked with dislocations [8].…”

“…Deep level transient spectroscopic studies (DLTS) carried out on plastically deformed (700 ± C) p-Si [15] reveal a band around E y 1 0.47 eV which has been correlated with the D1 to D4 optical bands. The density of levels, ϳ1 3 10 12 cm 23 , corresponds to an upper limit of about one state per ten spacings along the dislocation line.…”

Evaluation on electrical resistivity of silicon materials after electron beam melting

“…[5][6][7][8] Oxygen precipitation is known to act as intrinsic gettering sites for impurities and to affect mechanical strength of the wafer. 9,10 Oxygen can form a variety of inhomogeneous defects, such as thermal donors 11,12 due to the clusters of oxygen atoms 13,14 and some other donors due to the SiO 2 precipitates. 5,6 Except for those inhomogeneous defects, there is another kind of uniformly distributed defect: boron-oxygen complexes, which is responsible for an asymptotic, up to 10% degradation of solar cell performance by relative when the timescale of illumination is close to hours.…”