Chemical solution deposition of PZT thin layers on silicon: Densification and stress development

Abstract

The chemical method of solution deposition of Pb(Zr_0·53Ti_0·47)O₃(PZT 53/47) thin layers on silicon involves shrinkage and stress development with heat treatment. Results are reported for shrinkage, as determined by in situ ellipsometry, and stress, measured by in situ laser reflectance, up to a maximum temperature of 700°C. Densification, thermal analysis, pyrolysis and crystallisation data are given and related to stress development as a function of sequential buildup of additional layers. For example, a residual tensile stress of around + 125 MPa was measured at room temperature for the first layer (inferred to be amorphous by the lack of XRD response). The stress magnitude decreased with increasing number of layers deposited. Observations are reported for the crystallisation of a fluorite phase on Si, and the formation of a lead silicate interfacial layer.