Predictive Modelling Methodologies for Bi-Material Wafer Warpage

Wafer warpage modeling is challenging for semiconductor industry because simulation tools need to consider multi-physics behavior and non-linear material properties. This paper conducted a wafer warpage experiment and simulation on bi-material wafer which consists of silicon and substrate's polymer materials. In the experiment, the bimaterial wafer was thermally cured along a temperature profile with warpage measurement. For modelling study, pressure-volume-temperature-cure (PVTC) effect and visco-elastic (VE) with time-temperature shift factor (TTS) were considered in the polymer material model. The simulation results were compared with the experiment data.