A software tool, TRAVIT, has been developed to simulate dry etch in maskmaking. The software predicts the etch profile, etched critical dimensions (CDs), and CD-variation for any pattern of interest. The software also takes into account microloading effect that is pattern dependent and contributes to CD variation. Once CD variation is known, it can then be applied to correct the CD-error. Examples of simulations including variable ICP power, physical and chemical etch components, and optimization of a bias and CD variation are presented. Incorporating simulation into the maskmaking process can save cost and shorten the time to production.