Limits of the copper decoration technique for delineating of the V–I boundary

Abstract

Copper decoration technique was used for detection of the vacancy–interstitial (V–I) boundary in Czochralski silicon crystal. We used the technique for delineating defects in silicon previously reported by Mule’Stagno [Solid State Phenom. 82–84 (2002) 753] and we enriched it by an upgraded application of copper on the silicon surface. The new procedure is based on the deposition of elementary copper on the silicon surface from the copper nitrate solution. The new method is more efficient contrary to Mule’Stagno (2002) and it also decreases environmental drain. We compared five etchants in order to optimize the delineation of the V–I boundary. A defect region of the same diameter was detected by all the used etchants, supreme sensitivity was obtained with Wright's etchant. The outer diameter of the defect region observed by the copper decoration technique coincides with the V–I boundary diameter measured by OISF testing and approximately coincides with the V–I boundary diameter measured by COP testing. We found that the copper decoration technique delineates oxygen precipitates in silicon and we observed the dependence of V–I boundary detectability on the size of the oxygen precipitates.