Advanced test structure design for dielectric characterisation of novel high-k materials

The extremely high level of integration currently required within the wireless industry poses significant challenges at all technology steps from materials through processing to packaging. Capacitor design is a very important element of this technology integration challenge. Recently there has been strong interest in the use of PMNT (Pb(Mg,Nb)TiO₃) as a thin-film layer in semiconductor processes [1]. The high dielectric constant of PMNT makes it an attractive material for the fabrication of MIM (Metal/Insulator/Metal) decoupling capacitors. Before PMNT can be used in conjunction with a modern Si process for capacitor design the PMNT layer must be accurately characterised. This paper addresses the issue of thin- film characterisation through wafer-probe measurements and electromagnetic simulation (EM) of coplanar waveguides. Based on the results obtained a design methodology for optimum test structure layout is presented.