METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To reliably interpose an insulation film having a low permittivity between interconnections having a small wiring pitch, and also to prevent the occurrence of such defects as peel-off and scratches of the insulation film having a low permittivity. SOLUTION: On a silicon substrate 100, a first insulation film 101 constituted of an inorganic film 101 having a low permittivity is formed. Then, the first insulation film 101 is so patterned as to be left over in a region which needs a specifically low capacitance between interconnections. After forming a second insulation film 103 constituted of a silicon oxide film on the silicon substrate 100, the second insulation film 103 is flattened by polishing by CMP method, to expose the surface of the first insulation film 101 and then make the first insulation film 101 and the second insulation film 103 nearly flushed with each other. After forming interconnection trenches 105 in the first insulation film 101 and the second insulation film 103, the trenches 105 are filled with a metal film to form metal interconnections.