METHOD FOR FORMATION OF METAL INTERLAYER INSULATING FILM IN SEMICONDUCTOR DEVICE

PURPOSE: To form a metal interlayer insulating film of superior flatness with no void or crack by, after different insulating films have been exposed according to protruding and recessed parts, respectively of a substrate region provided with a metal pattern, forming an insulating film provided with base-dependence on top surfaces thereof. CONSTITUTION: On the top surface of a semiconductor substrate 21 on which a specified metal layer pattern 23 has been formed, a first insulating film 25 and a second insulating film 27 are formed in this order. Then the second insulating film 27 is etched back to form a spacer, comprising a part of the second insulating film 27, on a sidewall of the first insulating film 25. Then a third insulating film 29, whose growing speed on the spacer is higher than that on the first insulating film 25, is formed on the first insulating film 25 and the spacer. For example, one of PSG, O3 -TEOS PSG, O3 -TEOS BPSG, P-TEOS USG is used for the first insulating film 25, and one of P-SiH4 USG, O3 -TEOS USG is used for the second insulating film 27. O3 -TEOS USG is used for the third insulating film 29.