A new method to correct x-ray mask distortion was developed. This method uses the correction method of previous analysis of distortion and transformation of coordinates (PAT) and a simulator to calculate pattern displacement caused during backetching. The key advantages of using PAT with a simulator are that no extra time, substrates, or labor are required to fabricate send-ahead mash. Using this correction method, it was confirmed that the 3 sigma value of the pattern placement error was reduced to below 76 nm. This indicated that PAT with a pattern displacement simulator was as useful for improving the pattern placement accuracy of x-ray masks as PAT with send-ahead masks. In addition, analysis of the remaining error made it clear that the correction error was mainly caused by the lack of e-beam writing accuracy.