This article proposes a dynamic process window matrix for effective lithography development based on accurate resist profile simulation. This process window is defined on an exposure dose-defocus plane as the area that is determined by linewidth error and sidewall angle at the resist thickness corresponding to the maximum and minimum linewidths. This window concept can give a practical process margin, since standing wave effects are also taken into consideration. This method is applied to the analysis of chemically amplified resist system for KrF excimer laser lithography.