Manufacturing method of flash memory device

A manufacturing method of a flash memory device, comprising the steps of:

• (a) forming a flash memory cell on a semiconductor substrate;
• (b) forming wiring which include a metal above said flash memory cell;
• and
• (c) forming second interlayer insulating films on said wirings;
• wherein
• in said step (c), a furnace anneal is performed at least once or more as a heat treatment.

A manufacturing method of a flash memory device, comprising the steps of:

• (a) forming a flash memory cell on a semiconductor substrate;
• (b) forming wirings which include a metal above said flash memory cell;
• and
• (c) forming second interlayer insulating films of a multilayer structure on said wirings;
• wherein
• in said step (c), a deposition temperature of each layer of said multilayer structure is the same.

A manufacturing method of a flash memory device, comprising the steps of:

• (a) forming a flash memory cell on a semiconductor substrate;
• (b) forming wirings which include a metal above said flash memory cell and performing a furnace anneal;
• and
• (c) forming second interlayer insulating films on said wirings.