Effects of the deposition conditions of the seed layer on the crystallinity and electrical characteristics of the Pb(Zr,Ti)O-3 films

Abstract

Pb(Zr,Ti)O-3 (PZT) films were deposited on Pt/Ti/SiO2/Si substrates by electron cyclotron resonance (ECR) plasma enhanced DC magnetron reactive sputtering. Various seed layers with different compositions were formed by varying the target power of each element at the initial stage of the deposition process, and the effects of the seed layers on the properties of the PZT films subsequently deposited on them were studied. The seed layers were fabricated in three ways: increasing Pb flux at a particular Zr/Ti flux ratio which is kept constant in the subsequent PZT film deposition process, increasing Pb flux with decreasing the Zr/Ti flux ratio to make the layer composition below the morphotrophic phase boundary (Zr/Ti=1.08) value and finally maintaing a Zr flux of zero for the PbTiOx seed layer. It was found that the PZT seed layer is more effective than a PbTiOx seed layer and the effectivity of the seed layer is increased not by just increasing the supply of Pb, but by increasing the Pb supplement in the presence of low Zr/Ti flux ratio. However, too much excess supplement of Pb element during the seed layer deposition degrades the crystallinity and capacitance properties of overlying PZT films.