| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor storage device having a capacitor with improved reliability while reducing a leak current by controlling a shape at the upper end of a lower electrode of a DRAM capacitor without adding a special process, and to provide a method of manufacturing the same. <P>SOLUTION: The method of manufacturing the semiconductor storage device includes as follows. The lower electrode 51, which is formed on the inner wall of a cylinder hole cylindrically opened to an interlayer insulating film, is formed of a laminated-structure conductive film comprising a first titanium nitride film and a second titanium nitride film having a nitrogen content ratio higher than that of the first titanium nitride film. Next, the conductive film is left only on the inner face of the hole by etching with a reactive-ion etching method on the condition that an etching rate of the second titanium nitride film is higher than that of the first titanium nitride film. The cup-shaped lower electrode, in which an angle formed by the upper end face of the conductive film left only on the inner face of the hole and the internal face of the hole is ≤45°, is formed. In that state, the capacitor is composed by sequentially forming a capacitance insulating film and an upper electrode on the lower electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT |
