Investigation on the properties and processability of polymeric insulation layers for through silicon via

3D packaging using through silicon via (TSV) technology is becoming important in IC packaging industry. In this paper, the TSV process uses a polymeric liner as insulation material and a buffer for thermo-mechanical stress relaxation. Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), dielectric and contact angle tests are applied to select a suitable dielectric from two kinds of polymers. All the properties show that the linear o-crosel phenolic (LOPF) is suitable for acting as an insulation liner in the TSV process. Then the LOPF liquid is spun on the wafer, followed by soft baking at the temperature of 115 °C, the processed wafer is inspected using optical microscope, step profiler and scanning electron microscope (SEM). All the results indicate that LOPF has good potential to be the insulation layers for TSV.