| 摘要 |
PURPOSE: A method is provided to restrain a leakage current from leaking out of a tantalum oxide film by a method wherein the tantalum oxide film is formed as thick as required and repeatedly subjected to a thermal treatment which is carried out twice or more at a specific temperature or above for the formation of a capacitor insulating film. CONSTITUTION: A first tantalum oxide film is formed as a capacitor insulating film through an LP-CVD method. The film is formed at a temperature of 450°C using material composed of pentaethoxytantalum and oxygen which are each supplied at flow rates of 0.1 ml/min and 2SLM. The film is formed as thick as 5 nm under a pressure of 1 Torr (about 133Pa). In succession, the first tantalum oxide film is thermally treated in an oxygen atmosphere at a temperature of 800°C for ten minutes in an electric oven for the formation of a first crystallized tantalum oxide film(207) (an amorphous tantalum oxide film is turned crystalline by thermal treatment). Furthermore, a second tantalum oxide film is formed as thick as 5 nm on the first crystallized tantalum film(207). Then, a thermal treatment is carried out at a temperature of 800°C for ten minutes in an oxygen atmosphere in an electric oven for the formation of a second crystallized tantalum oxide film(209).
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