J. Raebiger et al., CARRIER LIFETIME AND X-RAY-IMAGING CORRELATIONS OF AN OXIDE-INDUCED STACKING-FAULT RING AND ITS GETTERING BEHAVIOR IN CZOCHRALSKI SILICON, Applied physics letters, 69(20), 1996, pp. 3037-3038
The characterization of a unique crystal originated and thermally acti
vated defect zone in Si wafers called an oxide-induced stacking fault
(OSF) ring has been carried out using two noncontacting techniques. Th
e minority-carrier lifetime has been mapped using the laser microwave
photoconductance decay (LM-PCD) method and correlated with a transmiss
ion x-ray topographic image of the wafer. Additional details of the la
teral and depth dependent stacking fault density were revealed by pref
erential etching. The minority-carrier lifetime within the annular OSF
ring itself was about one order of magnitude lower than that outside
the ring, while intermediate lifetime values were observed inside the
ring. Temperature-dependent LM-PCD measurements revealed that a redist
ribution of the metallic impurity Fe occurred via gettering by the sta
cking faults. These findings were confirmed and quantified by deep-lev
el transient spectroscopy. Implications for radial variations in devic
e yield are discussed in the context of the depth distribution of the
extended defects, their impurity gettering action, and wafer-to-wafer
variations in the nature of the OSF ring. (C) 1996 American Institute
of Physics.