PZT MMIC via hole fabrication technique / Raudah Abu Bakar

This study is carried out in order to investigate the effects of via hole grounding in newly proposed high dielectric constant material, lead zirconate titanate (PZT) thin films for MMIC applications. To predict the performance of via hole in PZT thin films, 50 x 50 ^im2 square and cylindrical vias of various diameters were simulated using CST Microwave Studio over 0.1 to 20 GHz frequency range. The via test structures were patterned using a combination of electron beam lithography and wet etching technique for on-wafer characterization and were metallized with sputtered gold. The on-wafer characterization was performed using a Wiltron 37269A vector network analyzer and Cascade Microtech probe station with Cascade Infinity probes. The values of the resistance and inductance extracted from the simulation and measurement data were compared. The measured results exhibit inductive behavior which is similar to those obtained from the simulation, indicating successful via realization using a new wet etching technique with 0.5HF : 5HC1 : 10NH4C1 : 5OH2O composition. However, the inductance (18.839 pH) and resistance (1.212 £1) are found to be higher than the simulated values.