w ions from remaining on the second interlayer insulating film 120 therefore the leakage of current or a short circuit between metal interconnects due to co ions or w ions can be prevented referring to fig8 the planarization pattern 170 remaining on the first capping pattern 160 is removed for example the planarization pattern 170 may be selectively removed using an etchant that has a high selectivity of the planarization pattern 170 to other films i e the selective metal diffusion barrier 180 and the first capping pattern 160 the etchant may be for example hydrofluoric acid hf in the current exemplary embodiment the wet etching method is used as an example however any method that ensures a high selectivity of the planarization pattern 170 to other films can be used referring to fig9 a second capping film 190 is further formed on the first capping pattern 160 and the selective metal diffusion barrier 180 the second capping film 190 may be optionally formed if necessary specifically the second capping film 190 may contain at least one of sic sicn sico and sin the second capping film 190 and the first capping pattern 160 may be the same material or.