interconnection layer 13 can eliminate the step of forming a contact hole to the lower electrode 6 in another embodiment of this invention the second interlayer film may be removed while forming a contact hole to the second interlayer film a contact hole may be selectively formed to the first interlayer film exposed in the area where the second interlayer film has been removed and the interconnections may be simultaneously formed in the contact holes formed in the first and the second interlayer films specifically in the substrate for which the steps to formation of the second interlayer film 11 have been completed as described above fig2 a a contact hole 12 a to the pd is formed in the second interlayer film 11 by dry etching using cf 4 and o 2 as etchants as described above while removing the second interlayer film 11 over the tft as illustrated in fig2 b then as illustrated in fig2 c dry etching is conducted while covering the areas except for the area where a contact hole 12 b is to be formed with a mask to form the contact hole 12 b to the first interlayer film it is preferable to use cf 4 and h 2 as etchants in such a mixture ratio that a.