| 摘要 |
A method of manufacturing DRAM capacitor includes forming a tungsten plug to connect with the source/drain region of a silicon substrate and using tungsten to form the upper and lower electrodes of the capacitor. The tungsten lower electrode of this invention is formed by depositing tungsten over the substrate using a physical vapor deposition method, and then depositing tungsten again using a chemical vapor deposition method so that a roughened surface is produced. Consequently, the tungsten lower electrode has a greater surface area, thereby increasing the capacitance of the capacitor. In addition, tantalum pentoxide is used to form the dielectric layer. Since tantalum pentoxide has a high dielectric constant, the effective capacitance of the capacitor is further increased.
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