Method for making semiconductor device having ferroelectric capacitor therein
A ferroelectric capacitor provided with a ferroelectric film ( 10 a ) is formed above a semiconductor substrate, and thereafter a wiring ( 17 ) directly connected to electrodes ( 9 a, 11 a ) of a ferroelectric capacitor is formed. Then, a silicon oxide film ( 18 ) covering the wiring ( 17 ) is formed. As the silicon oxide film ( 18 ), a film which has processability higher than that of an aluminum oxide film is formed. Besides, a degree of damage that occurs in the ferroelectric capacitor when the insulating film is formed is equal to or less than that when an aluminum oxide film is formed.
1. A method for manufacturing a semiconductor device, comprising:
forming a ferroelectric capacitor provided with a ferroelectric film above a semiconductor substrate;
forming a wiring on and directly connected to an electrode of the ferroelectric capacitor;
forming a silicon oxide film with a thickness of between 20 nm and 100 nm covering at least an upper surface of the wiring by sputtering method; and
forming a first plasma oxide film over the silicon oxide film by plasma CVD method, a lower surface of the first plasma oxide film being in contact with an upper surface of the silicon oxide film;
wherein the method further comprises forming an aluminum oxide film over and in contact with the first plasma oxide film.
2. The method for manufacturing a semiconductor device according to claim 1 , wherein a film containing at least one kind of impurities selected from the group consisting of phosphorous and boron is formed as the silicon oxide film.
3. The method for manufacturing a semiconductor device according to claim 1 , wherein:
the ferroelectric capacitor includes a lower electrode, the ferroelectric film on the lower electrode and an upper electrode on the ferroelectric film;
the wiring is a first wiring, the electrode is the lower electrode, wherein the device further includes a second wiring which is connected to the upper electrode; and
a part of the plasma oxide film is located between the first wiring and the second wiring.
4. A method for manufacturing a semiconductor device, comprising:
forming a ferroelectric capacitor provided with a ferroelectric film above a semiconductor substrate;
forming a wiring on and directly connected to an electrode of the ferroelectric capacitor;
forming a silicon oxide film with a thickness of between 20 nm and 100 nm covering at least an upper surface of the wiring by sputtering method; and
forming a first plasma oxide film over the silicon oxide film by plasma CVD method, a lower surface of the first plasma oxide film being in contact with an upper surface of the silicon oxide film;
further comprising performing nitrogen gas (N 2 ) annealing to said silicon oxide film.