roughness and the lwr line width roughness this is realized since the projected portions on the side walls of the mask pattern are removed by the incident ions whereas the recessed portions are subjected to deposition of deposition radicals so that the balance of incident ions and deposition radicals determine how much the ler and lwr are reduced next the embodiment regarding the method for controlling the sparse pattern dimension and dense pattern dimension in the deposition step of the present invention shown in fig1 will be described the gradient of the deposition curve c 4 illustrating the time variation of the sparse mask dimension and dense mask dimension described in embodiment 1 can be controlled via apparatus control parameters such as pressure flow rate gas species and rf bias power chf 3 gas is used similarly as embodiment 1 with the pressure set to 2 pa the flow rate set to 100 ml min and the rf bias voltage set to 0 w and the time variation of the sparse mask and dense mask dimensions is examined the examination result is shown via triangle plots in fig3 d and a deposition curve c 41 connecting the examination points is drawn similarly as embodiment 1 as can be seen from this curve the result of the sparse pattern being wider than the dense pattern is the same as embodiment 1 however the gradient of the deposition curve c 41 differs from the gradient of the deposition curve c 4 of the condition of embodiment 1 and it can be seen that the condition does not allow a large sparse dense difference thus we will now describe how the gradient of.