Towards highly integrated, automotive power SoCs using capacitors operating at 100 V implemented in TSV

In this work, we report on the implementation of 3D silicon capacitors for the use in 50-100 V automotive applications as capacitive DC-DC converters operating in the MHz range. The fabrication process of the capacitors is based on the through-silicon-via technology and can be integrated into smart-power ICs and silicon interposers towards highly integrated power system-on-a-chip in the frame of an automotive qualified 350 nm Si-technology. High reliabilities and breakdown voltages up to 290 V (16 MV/cm) were achieved for present capacitors with a confined hole-patterns design. An integration density of 1.8 nF/mm(exp 2) was demonstrated for this approach. In addition, a detrimental wafer bow due to the mechanical stress of the thick dielectric layers can be considerably reduced by optimizing the design of the hole-patterns.