| 摘要 |
PROBLEM TO BE SOLVED: To keep a flattened insulating film, which is obtained by making a fluid insulating film undergo reflow processing, high in evenness without causing cracking to a semiconductor device, even if the flattened insulating film is subjected to a heat treatment later. SOLUTION: A first lower insulating film 42 of NSG is formed on a semiconductor substrate 31 provided with a lower wiring 36 covering the lower wiring 36. A second lower insulating film 43 of BPSG is formed on the first lower insulating film 42. The second lower insulating film 43 is turned fluid through a reflow process to make its surface flat. The second lower insulating film 43 is etched back until the first lower insulating film 42 is partially exposed in a memory cell region 31a. By this setup, the second lower insulating film 43 is isolated by the first lower insulating film 42. An upper wiring is formed on an etched-back surface A. |
