Abstract: The invention provides a method for generating scanning data used to control a photomask production system for producing a photomask for use in semiconductor production so as to produce a photomask having a pattern corrected in terms of the optical proximity effects wherein it is possible to perform data processing and data conversion associated with the correction in terms of the optical proximity effects without introducing significant rounding errors, and it is possible to make correction in terms of the optical proximity effects without increasing the time required to produce the photomask, and furthermore it is possible to easily deal with a change in the process condition such as the resist exposure condition.

Abstract: A method for washing a photomask substrate or a semiconductor wafer. The mixing heat generated on mixing H.sub.2 SO.sub.4 and H.sub.2 O.sub.2 is effectively utilized for promoting the reaction. H.sub.2 SO.sub.4 and H.sub.2 O.sub.2 are discharged from separate nozzles and mixed at a mixing point directly below and proximate to the nozzles to give a H.sub.2 SO.sub.4 --H.sub.2 O.sub.2 liquid mixture. The liquid mixture is caused to descend onto near the center of the photomask kept in rotation so that the liquid mixture is spread over the substrate surface under a centrifugal force. The H.sub.2 SO.sub.4 --H.sub.2 O.sub.2 flow ratios, the height of the mixing point and the number of revolutions of the substrate are controlled for providing the uniform temperature distribution of the liquid mixture on the substrate surface and for achieving uniform washing.

Abstract: A process of producing an exposure mask by which the accuracy of a pattern of a mask film to be formed on a surface of a transparent substrate is improved and also the accuracy in registration between layers is improved. The process comprises the step of correcting, upon exposure for the formation of a mask pattern, the position of a mask pattern by a different correction amount in accordance with a ratio at which the area of the mask film which remains after etching occupies in the entire area of a transparent substrate on which the mask film is formed.