Evaluation Of Electrical Properties And Sims Profiles On Forming Gas(N-2-H-2) Annealed Pt/Pzt/Pt Capacitors.

PZT is promising material for FeRAM. It has a serious problem on the CMOS wafer process that electrical properties are degraded with forming gas annealing. Recently, the degradation mechanism has been investigated actively, but it isn't understood enough. We studied electric properties and SIMS profiles after N-2-H-2 annealing on Pt/PZT/Pt capacitors. For the first time, we found that hydrogen atoms increased in PZT layer and oxygen atoms decreased in upper Pt layer after N-2-H-2 annealing. The nonvolatile polarization (Pnv) decreased in proportional to the hydrogen content in PZT. And the annealing induced the voltage shift of hysteresis when capacitors polarized before anneal. On the other hand, a clear corelation was not seen between Pnv and the oxygen content in Pt; however, the adhesion of Pt/PZT became poor in case of a small amount of oxygen in Pt. The oxygen in Pt has a contribution to the adhesion of Pt/PZT.