Copper precipitation in long‐time processed transistor samples

Abstract

Process‐induced crystal defects (point defects and extended defects) in completely processed transistor samples of floating zone silicon have been investigated by TEM analysis and DLTS measurements. It was possible to demonstrate that the lifetime of these samples is determined by the introduction of copper during the long‐time processing of the wafers. The predominant crystal defects within the wafer volume were found to be circular monolayers of copper silicide which due to their appearance could be easily confounded with stacking faults.

Elektrische Eigenschaften von eisendotiertem Silizium in verschiedenen Stadien der Ausscheidung

“…Iron, copper, nickel and cobalt are the most common impurities in silicon device fabrication. The precipitates of copper are known to reduce the lifetime of the electronic device [3]. Copper [4] and nickel [5] cause a breakdown in the silicon oxides.…”