| 摘要 |
PROBLEM TO BE SOLVED: To prevent the nonconformity that oxygen which has permeated a lower electrode oxidizes a barrier layer and forms a high-resistance layer when a dielectric film on the lower electrode of the capacitance element of a DRAM, is heat-treated in an oxygen atmosphere. SOLUTION: The lower electrode 31 which is composed of a TaN film, and an Ru film deposited on its upper part is constituted at the inside of a groove 27 formed on a silicon oxide film 24. In succession, a tantalum oxide film 32a is deposited on the upper part of the lower electrode 31 by CVD method. After that, in order to crystallize the film 32a and to improve its film quality, it is heat-treated at 300 to 400 deg.C in an oxygen-containing atmosphere. Thereby, the nonconformity of a high-resistance oxide layer being formed between a plug 22 composed of polycrystalline silicon and the lower electrode 31 is prevented. |
