| 摘要 |
PURPOSE:To prepare a memory cell which has extremely smal leakage current in a high yield by forming an isolating structure between memory cells in an insulating film structure formed by an accumulating method on a gate insulating film. CONSTITUTION:A memory cell is formed of a P type silicon substrate 25, a source 26a, a drain 26b, a silicon nitride film 27 to become a gate insulating film, a silicon oxide film 28 formed by a CVD method, an MOS diode electrode and memory electrode 19, and a PSG protecting film 30. Since the film 28 formed by using the CVD method as a field insulating film of the isolation unit does not have extremely different film growth locally on the surface of the silicon at the film forming time and heat treating step of long time which causes a local distortion in the silicon in the later manufacturing steps, the stress of the isolating end can be eliminated to form a memory cell structure of extremely low leakage. |
