Cleaning method for controlling reticle CD value

The invention provides a cleaning method for controlling a reticle CD value, comprising the steps as follows: obtaining the altering amplitude of the reticle CD value along with the variation of the second sulphuric acid cleaning time and the altering amplitude along with the variation of oxydol injection amount; collecting reticle CD data, and determining the second sulphuric acid cleaning time and/or oxydol injection amount by the step 1 according to the amplitude of the reticle CD value exceeding the expected CD value range; cleaning a reticle according to the second sulphuric acid cleaningtime and/or oxydol injection amount determined in the step 2; recollecting the reticle CD value and judging whether the CD value is within the expected range or not, if so, finishing the cleaning, and otherwise, returning to the step 2. The invention controls the reticle CD value by effectively regulating the second sulphuric acid cleaning time and the oxydol injection amount, and solves the problem of waste recticle wit