Backside Transistor Contacts for Lower Parasitic Power IC Routing

The patent inverts the conventional interconnect approach by routing power and ground contacts through the backside of the substrate rather than the frontside. This inversion allows power and ground interconnects to be formed beneath the transistor channels, eliminating the need for long lateral routing paths and reducing parasitic inductance and resistance. The backside contact structure achieves lower parasitic losses without significantly increasing fabrication complexity.

The patent transitions from two-dimensional planar interconnect routing on the frontside to three-dimensional vertical routing through the substrate thickness. By forming contact holes through the substrate and routing interconnects in the vertical dimension, the design reduces the lateral path length for power and ground signals, thereby minimizing parasitic effects while maintaining structural simplicity.

The patent segments the interconnect structure into separate frontside and backside components. Power and ground contacts are formed independently on the backside through dedicated contact holes, while the frontside maintains standard device structures. This segmentation allows parasitic reduction without requiring complete redesign of the entire fabrication process, as each segment can be processed using modified but familiar techniques.

The backside contact structure serves multiple functions: it provides electrical connections for power and ground, acts as a thermal management path, and reduces parasitic effects. By consolidating these functions into a single structural approach, the patent achieves improved device efficiency without proportionally increasing manufacturing complexity, as the same backside contact structure fulfills multiple roles.