Mitigating TSV-induced substrate noise in 3-D ICs using GND plugs

Abstract

Through-silicon vias (TSVs) in 3-D ICs are a major source of substrate noise, causing performance degradation of neighboring active devices. To reduce this noise, we propose using a tungsten-filled ground plug, a TSV-like structure that connects to ground (GND) and that partially or completely extends through the substrate. We evaluate the impact of plug size and placement on noise isolation. We compare the GND plug technique with two other noise mitigation techniques: using a thicker dielectric liner and using a backside ground plane. Our study demonstrates that the GND plug is a superior technology, effective in mitigating TSV-induced substrate noise by an order of magnitude when compared to the other two techniques. The GND plug offers a more practical noise isolation approach than using a backside ground plane. When compared with increased dielectric thickness, the GND plug offers a 33% reduction in foot print and permits a significantly reduced keep out zone.