New defect size distribution function for estimation of chip critical area in integrated circuit yield models (CMOS)

The Gamma function is proposed to approximate the measured lithographic defect size distribution for the estimation of the chip critical area. It is shown that, compared to the commonly used 1/x³ function for approximation of the lithographic defect size distribution, the Gamma function provides much better agreement with the measured data, thus leading to a more accurate estimation of the chip critical area.