| 摘要 |
PURPOSE: A method of forming a capacitor is provided to prevent a lower electrode from being flaked at a high-temperature thermal annealing. CONSTITUTION: In a method of forming a capacitor, a first silicon oxide film(2) is formed on a silicon substrate(1), and a titanium film having a thickness of 100 to 300 Angstroms is deposited on the silicon oxide film(2). An annealing is executed at an oxygen atmosphere of 600 to 800°C so as to form a titanium oxide film(3). A titanium film having a thickness of 1000 to 3000 Angstroms is formed on an entire surface, and is selectively etched to form a lower electrode(14). A second silicon oxide film(5) having a thickness of 1000 to 2000 Angstroms is formed on an entire surface of a resultant structure. A surface of the lower electrode(4) is exposed by selectively removing the second silicon oxide film. A half of a desired thickness of an SrBi2Ta2O9 film is formed on an entire surface by use of a sol-gel method, and then a rapid thermal annealing is performed during 30 seconds at a temperature of 725°C in an oxygen atmosphere. The other half of the desired thickness of a SrBi2Ta2O9 film is formed in the same manner as forming the half of SrBi2Ta2O9. An annealing is performed during one hour at a temperature of 800°C in an oxygen atmosphere. Thus, a SrBi2Ta2O9 ferroelectric film(6) is formed on the lower electrode(4) and the silicon oxide film(5).
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