With the use of the resist mask as a mask, a portion of the insulating layer 106 is selectively removed to form an opening 181_1 to an opening 181_3 (see FIG. 8B). After that, the resist mask is removed. When the openings are formed, a portion of the insulating layer 103 is also removed in some cases. The insulating layer 106 can be removed by a dry etching method, a wet etching method, or the like. Both the dry etching method and the wet etching method may be used.
[Step 3]
Next, a conductive layer 182a and a conductive layer 182b are formed over the insulating layers 103 and 106 (see FIG. 8C). In this embodiment, a tantalum nitride film is formed by a sputtering method as the conductive layer 182a. A tungsten film is formed by a sputtering method as the conductive layer 182b.
[Step 4]
