Manufacturing method of semiconductor device
View Patent ↗A first structure is formed, having a contact plug formed on the bottom of a first opening in an interlayer insulating film, a second opening formed through the interlayer insulating film to reach a semiconductor substrate, and a third opening formed through the interlayer insulating film to reach a polymetal gate electrode. A cobalt layer is deposited on the surface of the structure, and thermally treated to form a cobalt silicide layer on the surface of the contact plug and on the bottom face of the second opening. The structure is then treated to remove the cobalt, in the state in which the cobalt silicide layer is formed, with the use of a chemical solution capable of dissolving cobalt but not the polymetal.
1. A manufacturing method of a semiconductor device having a silicide film, comprising at least:
a first step of forming a first structure having a first opening formed through an interlayer insulating film to reach a contact plug, a second opening formed through the interlayer insulating film to reach a semiconductor substrate, and a third opening formed through the interlayer insulating film to reach a polymetal gate electrode;
a second step of depositing a cobalt (Co) layer on the surface of the first structure;
a third step of performing heat treatment to form a cobalt silicide layer on the surface of the contact plug and on the surface of the semiconductor substrate; and
a fourth step of removing unreacted cobalt (Co) from said third opening and exposing the surface of said polymetal gate electrode with the use of a chemical solution capable of dissolving cobalt (Co) but not the polymetal.
2. The manufacturing method of a semiconductor device according to claim 1 , wherein a metal film for preventing oxidation of cobalt (Co) is formed on the cobalt (Co) layer subsequent to the second step, and, after performing the third step, the metal film is removed by treating with a chemical solution prior to the fourth step.
3. The manufacturing method of a semiconductor device according to claim 1 , wherein the surface of the gate electrode is formed of tungsten (W).
4. The manufacturing method of a semiconductor device according to claim 1 , wherein the chemical solution capable of dissolving cobalt (Co) is a chemical solution having no oxidation effect on the surface of the gate electrode.
5. The manufacturing method of a semiconductor device according to claim 1 , wherein the chemical solution for dissolving cobalt is a mixed solution of sulfuric acid and water.
6. The manufacturing method of a semiconductor device according to claim 1 , wherein the chemical solution for dissolving cobalt is a mixed solution of hydrochloric acid and water.
7. A manufacturing method of a semiconductor device, comprising:
forming a plurality of openings through an interlayer insulating film, the openings exposing surfaces of different conductive materials;
depositing a cobalt layer on each of the exposed surfaces;
performing a heat treatment to form a cobalt silicide layer on a first group of the exposed surfaces; and
removing unreacted cobalt from a second group of the exposed surfaces using a chemical solution capable of dissolving cobalt to re-expose the second group of the exposed surfaces,
wherein the first group of the exposed surfaces includes a silicon substrate and a polysilicon plug.
8. The manufacturing method according to claim 7 , wherein the second group of the exposed surfaces includes tungsten.
9. The manufacturing method according to claim 7 , wherein the chemical solution capable of dissolving cobalt is a chemical solution having no oxidation effect on the second group of the exposed surfaces.
10. The manufacturing method according to claim 7 , wherein the chemical solution for dissolving cobalt is a mixed solution of sulfuric acid and water.
11. The manufacturing method according to claim 7 , wherein the chemical solution for dissolving cobalt is a mixed solution of hydrochloric acid and water.
12. The manufacturing method according to claim 7 , wherein the polysilicon plug contacts the silicon substrate.