| 摘要 |
PROBLEM TO BE SOLVED: To obtain a Pt film which has such a high oxygen barrier property that does not allow oxygen to reach a barrier layer through the Pt film by making the lengths of Pt crystal grains in the Pt film in the thickness direction of the film shorter than the thickness of the film and the length of intercrystalline boundaries longer than the thickness of the film. SOLUTION: After a TiN film 2 is formed on an Si substrate 1 as a barrier layer by sputtering, a Pt film 3 is formed on the film 2 by sputtering and the sputtering is temporarily stopped by lowering the power. Thereafter, the formation of the film 3 is restarted under the same condition. When the film 3 is formed in two stages in such a way, the lengths of Pt crystal grains in the thickness direction of the film 3 becomes shorter than the thickness of the film 3 and intercrystalline boundaries which are the permeating paths of oxygen can be made longer. Consequently, the oxygen barrier property of the film 3 can be improved and the thickness of the film 3 which is formed as the lower electrode of a capacitor can be reduced to 100nm. Therefore, the capacitance element of a DRAM can be made smaller in size and increased in degree of integration when capacitance and storage elements are formed by using this film 3. |
