Gettering of Copper by Defects in Silicon

Gettering of copper by defects in silicon was studied by preferential etching and optical microscopy. It was found that in p-type silicon,when the concentration of Cu impurity was not very high,most of the Cu precipitated on defects,including grain boundaries and dislocations; when heavily Cu contaminated,star-like Cu precipitates can be formed in silicon bulk,but defects also show great gettering effects for Cu,there was a precipitates DZ zone along the grain boundaries. In n-type silicon,grain boundaries and dislocations showed little gettering effect for Cu,while oxygen precipitates exhibited great gettering effect for Cu impurity,as well as retard effect for the diffusion of Cu in silicon.