US 11,840,759 B2
Method of forming tungsten film and system therefor
Masafumi Takahashi, Nirasaki (JP); Kenji Suzuki, Nirasaki (JP); Tsuyoshi Takahashi, Nirasaki (JP); and Masaki Sano, Nirasaki (JP)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Mar. 7, 2022, as Appl. No. 17/653,690.
Claims priority of application No. 2021-037737 (JP), filed on Mar. 9, 2021.
Prior Publication US 2022/0290294 A1, Sep. 15, 2022
Int. Cl. C23C 16/02 (2006.01); C23C 16/455 (2006.01); C23C 16/14 (2006.01)
CPC C23C 16/0272 (2013.01) [C23C 16/14 (2013.01); C23C 16/45527 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method of forming a tungsten film, comprising:
preparing a substrate, which includes a vertical groove formed on a surface of the substrate and horizontal grooves formed in the vertical groove and arranged in a thickness direction of the substrate, wherein each of the horizontal grooves has an opening formed on a sidewall of the vertical groove and is formed as a recess extending horizontally from the opening;
forming a titanium nitride base film containing silicon in the recess of each of the horizontal grooves by alternately repeating:
precipitation of titanium nitride by alternately and repeatedly supplying a titanium-containing gas, which is a metal raw material-containing gas containing a titanium raw material, and supplying a nitriding gas to the substrate; and
precipitation of silicon nitride by alternately and repeatedly supplying a silicon-containing gas, which is a metal raw material-containing gas containing a silicon raw material, and supplying a nitriding gas to the substrate; and
subsequently, forming a tungsten film so as to bury tungsten in the recess of the each of the horizontal grooves, by alternately and repeatedly supplying a raw material gas containing a tungsten raw material and a reaction gas, which reacts with the raw material gas to precipitate the tungsten, to the substrate,
wherein a supply flow rate of the silicon-containing gas is adjusted so that a content of the silicon in the titanium nitride base film is high on an opening side of the recess rather than on an inner side of the recess.