Implementation of algorithms to determine the capacitance sensitivity of interconnect parasitics in the Magic VLSI layout tool [article]

Nick Kuan-Hsiang Huang
VLSI interconnect capacitance is becoming more significant and also increasingly subject to process variation in the deep submicron regime. A new set of capacitance models is implemented in the Magic VLSI layout tool to improve the capacitance accuracy based on 2.5D capacitance models. This involves a new technology file, equations, and search algorithms. In addition, a simple technique to extract from layout the sensitivity of interconnect parasitic capacitance to linewidth process variation
more » ... proposed based on the new capacitance models and implemented in Magic. The derivative of each extracted capacitance with respect to linewidth variation in every level is obtained. Coincident edges in layout result in distinct "shrinking" and "bloating" derivatives. The derivatives therefore form a gradient that may be multiplied by a vector of the variations on each level to give the total expected deviation from nominal capacitance. The gradient allows the process sensitivity of each capacitance to be determined by simply inspecting the netlist. In the end, the impact of process variation is simulated in a crosstalk application to emphasize the necessity of process variation awareness.
doi:10.14288/1.0067690 fatcat:sjismhemkfdv7ljw7jq43ichk4