Optimization of advanced MOS technologies for narrow distribution of circuit performance

A methodology is investigated to optimize technological parameters to reduce distribution of circuit performance. Major attention is paid to treat all characteristics from device level to circuit level on one basis, namely technological parameters. The key point of the whole procedure is the quality of the analytical MOSFET model used for circuit simulations. Due to the physical description of our model, only three independent technological parameters have to be studied, namely the effective channel length, the oxide thickness, and the substrate doping concentration. These values are available directly or indirectly from measurements. The methodology is applied to optimize the oxide thickness for a 23-stage ringoscillator to get narrow delay distribution for low voltage application.