In the Mask D2I project at ASET, the authors assembled an electron beam exposure system to prove the concept of the multicolumn cell with character projection capability. They performed beam calibrations in individual column cell to evaluate beams after character deflections. They measured the impacts on beam positions in one column cell caused by deflections in other column cells and concluded that there were no deflection impacts on beam positions from neighboring column cells in the multicolumn cell system. They also evaluated stitching errors of the patterns exposed by different column cells. Present stitching errors of the patterns between the different column cells were estimated to be less than 20 nm.