| 摘要 |
PURPOSE:To increase capacitance per unit area and to reduce a leak current, by forming the first conductor layer of a thin film capacitor having a sandwich structure of the first conductor layer, an insulating layer and the second conductor layer with a specified material, and making the irregularities on the surface on the side of the insulating film smaller than the thickness of the film. CONSTITUTION:A lower electrode 4 is a molybdenum film, which is formed by a sputtering method and thereafter heat-treated in nitrogen at 1,000 deg.C and has a thickness of 3,000Angstrom . An insulating film 5 is a tantalum oxide film, which is formed by the sputtering method and has a thickness of 100Angstrom . An upper electrode 6 is a molybdenum film, which is formed by the sputtering method and has a thickness of 3,000Angstrom . The molybdenum film undergoes heat treatment at a high temperature, and its column crystal is transformed into a stone wall shaped crystal having a very flat surface. Therefore the surface irregularities are reduce, the diameter of the crystal grain becomes large and the irregularities is decreased. In this capacitor, the irregularities on the surface of the lower electrode are smaller than the thickness of the insulating film, and the leak current is decreased. |
