Experimental, analytical, and finite element analyses of nanoindentation of multilayer PZT/Pt/SiO₂thin film systems on silicon wafers

The mechanical properties of lead zirconate titanate (PZT) multilayer systems are needed to model and design micro-electromechanical systems (MEMS) devices. Nanoindentation is a promising tool for obtaining the elastic properties of thin films. However, no means exist to obtain the elastic modulus of the lead zirconate titanate (PZT) in the multilayer system. The indentation modulus versusa/tbehavior of the multilayered PZT/Pt/SiO₂film system on a silicon substrate was investigated and compared with finite element models and a new analytical solution. Six different PZT film thicknesses were indented (100, 140, 400, 700, 1500, and 2000 nm), using 5-, 10-, and 20-μm radius indenters. Good agreement was shown between the finite element analysis (FEA) and analytical solutions, and the experimental data. However the behavior of multilayer systems is complex, making deconvolution of properties difficult for films of less than a micron thick.