A practical attenuated phase-shifting mask (att-PSM) for 0.3 micrometers contact hole patterns with KrF excimer laser lithography has been developed by means of three important module processes which are supported by the precise process latitude evaluation using the EDM (Exposure, Defocus and Mask fabrication latitude) methodology. In order to evaluate the practical and reliable process latitude, the EDM methodology has taken into account the mask linewidth as well as the exposure dose and defocus parameters. From EDM evaluations, it has been found that the background transmittance of more than 9% and the phase error control of within +/- 3 degrees are required in order to obtain 1.5 micrometers depth of focus. The PSM feasibility has been effectively enhanced by three important module processes. First, quartz substrate engraving process for shifter pattern formation with RIE. Second, for the att- PSM inspection, the mask defect printability has been studied extensively, and the feasibility of a commercial PSM defect inspection system has been verified for several types of critical defects. Finally, for shifter protrusion defect repair, the Excess Deposition repair method has been developed with a focused ion beam, where a sufficient repair width latitude of +/- 0.13 micrometers is obtained.