Method of manufacturing a semiconductor device and a semiconductor manufacturing equipment
View Patent ↗A method of manufacturing a semiconductor device has polishing a film, and cleaning a polished surface by carrying out a first exposing the polished surface to an acidic first cleaning fluid having an effect of etching at least a partial region of the polished surface, and a second exposing the polished surface to an alkaline second cleaning fluid after the first exposing.
1. A method of manufacturing a semiconductor device, comprising:
forming a film over a semiconductor substrate;
polishing the film; and
cleaning a polished surface, which is formed by the polishing, by carrying out
a first exposing the polished surface to an acidic first cleaning fluid having an effect of etching at least a partial region of the polished surface; and
a second exposing the polished surface to an alkaline second cleaning fluid after the first exposing.
2. The method according to claim 1 , wherein the first exposing and the second exposing are carried out while holding the semiconductor substrate in an upright position.
3. The method according to claim 1 , wherein the first exposing is carried out without applying a cleaning brush to the polished surface.
4. The method according to claim 1 , wherein the second exposing is carried out while applying a cleaning brush to the polished surface.
5. The method according to claim 1 , wherein a silicon oxide film is exposed in the partial region of the polished surface, and hydrofluoric acid is used as the first cleaning fluid.
6. The method according to claim 1 , wherein ammonia water is used as the second cleaning fluid.
7. The method according to claim 1 , wherein a stepped portion is formed by the polishing in the polished surface in a boundary between the partial region and another region adjacent to the partial region.
8. The method according to claim 1 , wherein the polished surface is constructed from a silicon nitride film formed in another region adjacent to the partial region and a silicon oxide film formed in the partial region.
9. The method according to claim 8 , further comprising:
forming the silicon nitride film over the silicon semiconductor substrate;
forming an opening in the silicon nitride film in the partial region; and
forming a device isolation groove by etching the semiconductor substrate through the opening, wherein
when forming the film, the silicon oxide film is formed in the device isolation groove and over the silicon nitride film as the film, and
when polishing the film, the silicon oxide film is polished to be left in the device isolation groove as a device isolation insulating film, while using the silicon nitride film as a polishing stopper film.
10. The method according to claim 1 , wherein the polished surface is constructed from a tungsten film formed in another region adjacent to the partial region and a silicon oxide film formed in the partial region.
11. The method according to claim 10 , further comprising:
forming the silicon oxide film over the semiconductor substrate; and
forming a hole in the silicon oxide film in a portion other than the partial region, wherein
when forming the film, the tungsten film is formed in the hole and over the silicon oxide film as the film, and
when polishing the film, the tungsten film is polished to be left in the hole as a conductive plug, and the silicon oxide film is exposed in the partial region.
12. The method according to claim 11 , wherein the polishing of the tungsten film comprises:
a first polishing using a slurry in which a polishing rate of the tungsten film is faster than a polishing rate of the silicon oxide film; and
a second polishing using a slurry in which a polishing rate of the silicon oxide film is faster than a polishing rate of the tungsten film, after the first polishing step.