E ffect of oxygen precipitation on voids in bulk silicon

zhangcunbiao

E  ffect of oxygen precipitation on voids in bulk silicon
* Xuegong Yu, Deren Yang , Xiangyang Ma, Jin Xu, Liben Li, Duanlin Que
State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, PR China
Abstract
The effect of oxygen precipitation on flow pattern defects (FPDs) relative to voids in bulk silicon was
investigated. FPDs and voids were measured after different annealing time, and with various interstitial oxygen
contents and bulk stacking faults (BSFs). It was found that, during annealing, interstitial oxygen in bulk silicon
precipitated, however the FPDs density remained constant. The density of BSFs increased with annealing time at
1100 8C. After annealing, the morphology of voids was found to be octahedral with the oxide films inside them,
the same as as-grown samples. Therefore, it is concluded that the interstitial silicon atoms released during
oxygen precipitation did not enter the voids because of the resistance of the oxide films inside the voids, but
condensed into stacking faults. The dissolution of the oxide films is believed to be the principal cause for the
annihilation of voids.
  2002 Elsevier Science B.V. All rights reserved.
Keywords: Silicon; Voids; FPD; Oxygen precipitation; Self-interstitials
1   . Introduction
It is well recognized that the concentration of point defects in growing Czochralski (CZ) silicon
exceeds their thermal equilibrium concentrations, and hence excess point defects aggregate during