| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress electric-field concentration at a joint between a contact plug and a capacitor lower electrode. <P>SOLUTION: If chemical mechanical polishing is executed under the condition that a polishing rate ratio "c/d" is ≥3 when a polishing rate difference between tungsten and an interlayer insulating film 130 is large, and a polishing rate of the insulating film 130 is set as c and that of tungsten as d, the insulating film 130 retreats and the contact plug upper end part is exposed above the insulating film 130. The shape of the contact plug upper end part is machined into a hemispherical shape while advancing the chemical mechanical polishing of the insulating film. The capacitor lower electrode is formed by forming a conductive layer on the contact plug machined into the hemispherical shape. Therefore, the contact interface between the contact plug upper end part and the capacitor lower electrode becomes hemispherical. Consequently, it is possible to suppress the electric-field concentration when a voltage is applied since there is no acute-angled contact region. <P>COPYRIGHT: (C)2007,JPO&INPIT |
