Method of manufacturing semiconductor memory device

1. A method of manufacturing a semiconductor memory device comprising:

forming a first selection transistor and a second selection transistor;

forming a variable resistance element by sequentially laminating a first electrode that is connected to the first selection transistor, a variable resistance layer that contacts the first electrode, and a second electrode that contacts the variable resistance layer; and

forming a capacitance element by sequentially laminating a third electrode that is connected to the second selection transistor, a dielectric layer that contacts the third electrode and consists of the same material as the variable resistance layer, and a fourth electrode that contacts the dielectric layer;

wherein either one of the first electrode or the second electrode is formed with the same material as the third electrode and the fourth electrode, while the other one of the first electrode or the second electrode is formed with a different material than the third electrode and the fourth electrode, and

the semiconductor memory device is formed on a same semiconductor substrate with a non-volatile semiconductor memory element and a volatile semiconductor memory element, the non-volatile semiconductor memory element including the first selection transistor and the variable resistance element that is connected to the first selection transistor, and the volatile semiconductor memory element including the second selection transistor and the capacitance element that is connected to the second selection transistor.

2. The method of manufacturing a semiconductor memory device according to claim 1 , wherein other than forming the other one of the first electrode or the second electrode with a different material than the third electrode and the fourth electrode, the step of forming the volatile semiconductor memory element and the step of forming the non-volatile semiconductor memory element are essentially the same.

3. The method of manufacturing a semiconductor memory device according to claim 1 , the forming the variable resistance element and the forming the capacitance element further comprising:

simultaneously forming a first electrode dummy electrode and the third electrode with the same material;

forming the first electrode with a different material than the third electrode after removing the first electrode dummy electrode;

simultaneously forming the dielectric layer and the variable resistance layer on the first electrode and the third electrode, respectively; and

simultaneously forming the second electrode and the fourth electrode each consisting of the same material as the third electrode on the dielectric layer and the variable resistance layer, respectively.

4. The method of manufacturing a semiconductor memory device according to claim 1 , the forming the variable resistance element and the forming the capacitance element further comprising:

simultaneously forming the first electrode and the third electrode with the same material;

simultaneously forming the dielectric layer and the variable resistance layer on the first electrode and the third electrode, respectively;

simultaneously forming a second electrode dummy electrode and the fourth electrode with the same material as the first electrode and the third electrode on the dielectric layer and the variable resistance layer, respectively; and

forming the second electrode with a different material than the first, third, and fourth electrodes after removing the second electrode dummy electrode.

5. The method of manufacturing a semiconductor memory device according to claim 1 , the forming the variable resistance element and the forming the capacitance element further comprising:

simultaneously forming the first electrode and the third electrode with the same material;

simultaneously forming the dielectric layer and the variable resistance layer on the first electrode and the third electrode, respectively;

simultaneously forming the second electrode and a fourth electrode dummy electrode with a different material than the first and third electrodes on the dielectric layer and the variable resistance layer, respectively; and

forming the fourth electrode with the same material as the first and third electrodes after removing the fourth electrode dummy electrode.

6. The method of manufacturing a semiconductor memory device according to claim 5 , wherein the fourth electrode is laminated on the second electrode.

7. The method of manufacturing a semiconductor memory device according to claim 1 , the forming the variable resistance element and the forming the capacitance element further comprising:

simultaneously forming a first electrode dummy electrode and the third electrode with the same material;

removing a portion of the first electrode dummy electrode and forming the first electrode on the remaining first electrode dummy electrode with a different material than the third electrode;

simultaneously forming the dielectric layer and the variable resistance layer on the first electrode and the third electrode, respectively; and

simultaneously forming the second electrode and the fourth electrode each consisting of the same material as the third electrode on the dielectric layer and the variable resistance layer, respectively.

8. The method of manufacturing a semiconductor memory device according to claim 1 , wherein the material that constitutes the dielectric layer and the variable resistance layer includes any one or a mixture of a transition metal oxide, an aluminum oxide, and a silicone oxide.

9. The method of manufacturing a semiconductor memory device according to claim 8 , wherein the transition metal oxide consists of any one or a mixture of tantalum oxide, niobium oxide, hafnium oxide, and zirconium oxide.

10. The method of manufacturing a semiconductor memory device according to claim 1 , wherein the third electrode and the fourth electrode and either one of the first electrode and the second electrode are formed with any of tungsten, titanium, platinum, and gold.

11. The method of manufacturing a semiconductor memory device according to claim 1 , wherein the other one of the first electrode or the second electrode is formed with any of silver, copper, and zinc.