Method of forming contact holes in a semiconductor device having first and second metal layers

摘要

An exemplary method of forming a contact hole in a semiconductor device includes: forming a first insulation layer on a lower substrate; forming a first conductive layer on the first insulation layer; forming a second insulation layer on the first insulation layer and the first conductive layer; forming a second conductive layer on the second insulation layer; forming a third insulation layer on the second insulation layer and the second conductive layer; patterning a resist on the third insulation layer using an exposure mask of which transmittance is different at a region over the first conductive layer and at a region over the second conductive layer; and forming a first contact hole and a second contact hole by etching the resist and the third insulation layer such that the first conductive layer and the second conductive layer are exposed.