Tungsten film forming method, semiconductor device manufacturing method, and storage medium
A tungsten film forming method includes: supplying a tungsten chloride gas as a source material of tungsten and a reducing gas towards a substrate to be processed under a depressurized atmosphere to cause reaction between the tungsten chloride gas and the reducing gas while heating the substrate to be processed, such that a main tungsten film is directly formed on a surface of the substrate to be processed without forming an initial tungsten film for nucleus generation.
1. A tungsten film forming method, comprising:
supplying a tungsten chloride gas as a source material of tungsten and a reducing gas towards a substrate to be processed under a depressurized atmosphere to cause reaction between the tungsten chloride gas and the reducing gas while heating the substrate to be processed, such that a main tungsten film is directly formed on a surface of the substrate to be processed without forming an initial tungsten film for nucleus generation,
wherein the tungsten chloride gas is selected from a group consisting of WCl 6 gas, WCl 5 gas, and WCl 4 gas,
wherein the reducing gas is at least one selected from a group consisting of H 2 gas, SiH 4 gas, B 2 H 6 gas, and NH 3 gas, and
wherein a temperature of the substrate to be processed is 250 degrees C. or higher and an inner pressure of a reaction chamber is 10 to 30 Torr.
2. The tungsten film forming method of claim 1 , wherein the substrate to be processed has a base film as a surface layer and the surface of the substrate where the tungsten film is formed is a surface of the base film.
3. The tungsten film forming method of claim 2 , wherein the base film is a TiN film or a TiSiN film.
4. The tungsten film forming method of claim 1 , wherein the substrate to be processed has a depression, and the main tungsten film is formed in the depression such that the depression is filled with the main tungsten film.
5. A semiconductor device manufacturing method, comprising:
forming a base film on a surface of a substrate to be processed, the substrate to be processed having a depression on the surface thereof; and
filling the depression by supplying a tungsten chloride gas as a source material of tungsten and a reducing gas towards the substrate to be processed, which has the base film on the surface thereof, under a depressurized atmosphere to cause reaction between the tungsten chloride gas and the reducing gas while heating the substrate to be processed, such that a main tungsten film is directly formed on a surface of the base film without forming an initial tungsten film for nucleus generation and fills the depression,
wherein the tungsten chloride gas is selected from a group consisting of WCl 6 gas, WCl 5 gas, and WCl 4 gas,
wherein the reducing gas is at least one selected from a group consisting of H 2 gas, SiH 4 gas, B 2 H 6 gas, and NH 3 gas, and
wherein filling the depression is performed under conditions that a temperature of the substrate is 250 degrees C. or higher and an inner pressure of a reaction chamber is 10 to 30 Torr.
6. The semiconductor device manufacturing method of claim 5 , wherein the base film is a TiN film or a TiSiN film.
7. A non-transitory computer-readable storage medium operating on a computer and storing a program that controls a film forming apparatus, wherein, when executed, the program allows the computer to control the film forming apparatus such that the tungsten film forming method of claim 1 is performed.