Interconnect R/C Notes (cont).
Capacitance scaling
- Csub = L * W * C/unit area
- Interconnect length, width both reduced by alpha (reduces Csub by alpha squared), BUT thickness reduced by alpha, which increases capacitance by alpha, so total Csub only reduced by alpha
- Csub new = Csub old / alpha
- Cfringe new = Cfringe old/alpha
- If metal thickness increases, then Cfringe reduction not as great