Method of manufacturing semiconductor device
View Patent ↗A lower electrode of a capacitor element is formed by manufacturing a crown structure while using a first conducting material such as titanium nitride or the like excellent in mechanical strength as a base material and by forming a film of a second conducting material such as ruthenium or the like, which is comparatively difficult to be oxidized, on a surface of the crown structure. First, ruthenium is deposited on a surface of the crown structure by using a sputtering method. Thereafter, the ruthenium (sputtered ruthenium) placed in a peripheral region of the crown structure is removed by etching, and a film of ruthenium is further formed on a surface of the crown structure by using a CVD method while using the sputtered ruthenium as a seed layer.
1. A method of manufacturing a semiconductor integrated circuit device having plural capacitor elements, the method comprising the steps of:
forming plural cylindrical crown structures of a first conducting material in a first insulating film on a substrate of the device, parts of the first insulating film being between bases of each of said plural cylindrical crown structures;
depositing a second conducting material on interior and exterior walls and an interior bottom of each of said cylindrical crown structures and on the first insulating material between said plural cylindrical crown structures, said second conducting material being more difficult to oxidize than said first conducting material, said second conducting material being thicker at tops of said cylindrical crown structures than at the interior bottoms thereof;
removing said second conducting material from said first insulating material between said plural cylindrical crown structures and in a same step decreasing a thickness of said second conducting material at the tops of said cylindrical crown structures while retaining at least part of said second conducting material at the tops, on the interior and exterior walls, and on the interior bottom of each of said cylindrical crown structures;
following the removing step, growing a film of said second conducting material on the tops, interior and exterior walls and interior bottom of each of said cylindrical crown structures using the previously deposited said second conducting material as a seed for said film;
applying a second insulating film on the film of said second conducting material on the tops, the interior and exterior walls and the interior bottom of each of said cylindrical crown structures and on the first insulating material between said plural cylindrical crown structures; and
introducing oxygen into said second insulating film.