Plasma treatment after interconnect metal etch for recovery of plasma charge-induced damages

Abstract

Plasma charge-induced damage has been investigated during metal interconnection in SrBi,Ta,O,(SBT)-FeRAM device. The degradation of the ferroelectric characteristics, such as coercive voltage shift, was predominantly attributed to the metal etching that would inject electrons through the metal antenna and contacts. We also found that the degradation was not caused by a sputtering process in deposition of metal films or mechanical stress o f patterned metal pads. To recover the plasma charge-induced damage, we suggest that a soft plasma treatment after metal plasma etching can neutralize charge-up of the electrons so that the degradation of electric properties is minimized.