DUV scanner (4x) gate CD control was evaluated and compared with that of DUV stepper (5x) under the concept of total process proximity based correction (TPPC), merging all the process step error correction from mask fabrication to wafer etch process. We found that different iso-dense bias should be applied in the case of scanner. This is mainly caused by different optical proximity effect (DI-mask CD), that is, scanner shows nearly constant optical proximity effect regardless of the size of pattern CD while that of stepper is strongly dependent upon the size of pattern CD. Application of the concept of TPPC in DUV scanner enabled us to control FI CD within specification. A correction rule table was experimentally obtained using TPPC concept. Process capability of controlling gate CD in DRAM fabrication should be improved by this method.