Correlation method of circuit-performance and technology fluctuations for improved design reliability

We propose a method of correlating circuit performance with technology fluctuations during the circuit-design phase. The method employs test circuits sensitive for technology fluctuations and a circuit simulation model, which enables one to interpret the correlation. We validate our proposal with a cascode-current-source test circuit and the drift-diffusion MOSFET model HiSIM. The chosen test circuit allows one to separate intra-chip and inter-chip technology fluctuations and to correlate these fluctuations with circuit-performance fluctuations. One important result is that intra-chip fluctuations increase faster than inter-chip fluctuations with decreasing gate length. Quantitative modeling with HiSIM reveals random fluctuation of the effective gate length as the most likely origin for these findings