An interconnection structure of a semiconductor device and a method of manufacturing thereof

摘要

An aluminum interconnection film (49) has a three layered structure of an aluminum alloy film (33), a tungsten film (58), and a titanium nitride film (35). An aluminum interconnection film (61) and an aluminum interconnection film (49) are electrically connected through a through hole (55) formed in a silicon oxide film (51). Because light reflectivity of the titanium nitride film (35) is low, the exposed area of the resist can be kept within a predetermined area even if photolithography is carried out above a step (30) where light is irregularly reflected. Therefore, it is possible to form a through hole (55) of a desired dimension even if the through hole (55) is formed above the step (30). Even if the titanium nitride film (35) is etched and removed in forming the through hole (55), the aluminum alloy film (33) is not exposed since the etching speed of the silicon oxide film (51) is considerably slower than that of the tungsten film (58). The problem of denatured layer formation and residue formation caused by exposure of aluminum alloy film (33) does not occur.