| 摘要 |
PURPOSE:To lower the resistance of an interconnection on a recessed and protruding structure and to enhance the reliability of continuity at a contact by a method wherein a conductive film at a lower layer out of a plurality of conductive films is constituted so as to have the surface which has relaxed or flattened recessed and protruding parts of a substratum. CONSTITUTION:An n-type impurity layer 104 which is to be used as a source and a drain for a MOS field-effect transistor is formed; after that, an SiO2 film is deposited; an opening part 105 is formed. At this time, a word line 103 is covered with SiO2 films 106, 106', and its surface has a recessed and protruding structure. Then, a conductive film 107 of a bit line is filled on it, and the surface is flattened. Then, a conductive film 108 is deposited; the conductive films 108, 107 are etched sequentially; the bit line is formed. Thereby, it is possible to form a structure where the recessed and protruding structure has been flattened and a low-resistance material has been deposited. As a result, the resistance of an interconnection is lowered, and the speed of an LSI is increased. |
