Semiconductor device manufacturing method, semiconductor manufacturing apparatus and storage medium
View Patent ↗A seed layer is formed on a surface of an insulating film and along a recess of the insulating film, and after a copper wiring is buried in the recess, a barrier film is formed, and an excessive metal is removed from the wiring. On a surface of a copper lower layer conductive path exposed at the bottom of the recess, a natural oxide of the copper is reduced or removed. On a substrate from which the natural oxide is reduced or removed, the seed layer, composed of a self-forming barrier metal having oxidative tendency higher than that of copper or an alloy of such metal and copper, is formed. The substrate is heated after burying copper in the recess. Thus, a barrier layer is formed by oxidizing the self-forming barrier metal. An excessive portion of the self-forming barrier metal is deposited on a surface of the buried copper.
1. A semiconductor device manufacturing method comprising:
reducing or removing a natural oxide of copper on a surface of a lower layer conductive path exposed at a bottom of a recess formed in an interlayer insulating film of a surface of a substrate by supplying an organic acid to the substrate;
forming an oxygen supplying layer in the recess from organic acid;
forming a seed layer having a self-forming barrier metal along a wall surface of the recess on the substrate from which the natural oxide is reduced or removed;
after forming the oxygen supplying layer, burying, in the recess, copper forming an upper layer conductive path electrically connected to the lower layer conductive path via the seed layer; and
heating the substrate,
wherein until the seed layer is formed after the natural oxide of copper is reduced or removed, a formation of the natural oxide of copper is suppressed in an atmosphere to which the substrate is exposed.
2. The semiconductor device manufacturing method of claim 1 , wherein said heating the substrate is performed after copper is buried in the recess.
3. The semiconductor device manufacturing method of claim 1 , wherein said heating the substrate is performed while copper is buried in the recess.
4. A semiconductor device manufacturing method comprising:
reducing or removing a natural oxide of copper on a surface of a lower layer conductive path exposed at a bottom of a recess formed in an interlayer insulating film of a surface of a substrate by supplying an organic acid to the substrate;
forming an oxygen supplying layer in the recess from organic acid;
after forming the oxygen supplying layer, burying in the recess an alloy of copper and a self-forming barrier metal forming an upper layer conductive path electrically connected to the lower layer conductive path on the substrate from which the natural oxide is reduced or removed; and
heating the substrate,
wherein until the alloy is buried in the recess after the natural oxide of copper is reduced or removed, a formation of the natural oxide of copper is suppressed in an atmosphere to which the substrate is exposed.
5. The semiconductor device manufacturing method of claim 4 , wherein said heating the substrate is performed after the alloy is buried in the recess.
6. The semiconductor device manufacturing method of claim 4 , wherein said heating the substrate is performed while the alloy is buried in the recess.
7. The semiconductor device manufacturing method of claim 1 , wherein the seed layer is made of the self-forming barrier metal, or an alloy of the self-forming barrier metal and copper.
8. The semiconductor device manufacturing method of claim 1 or 4 , wherein the self-forming barrier metal has a function of preventing copper from being diffused by becoming an oxide.
9. The semiconductor device manufacturing method of claim 1 or 4 , wherein the self-forming barrier metal has oxidative tendency higher than that of copper.
10. The semiconductor device manufacturing method of claim 1 , wherein said heating the substrate is carried out to form a barrier film by oxidizing the self-forming barrier metal forming the seed layer and to deposit an excessive portion of the self-forming barrier metal on a surface of the buried copper.
11. The semiconductor device manufacturing method of claim 1 or 4 , wherein the atmosphere in which the formation of the natural oxide of copper is suppressed is an inert gas atmosphere.
12. The semiconductor device manufacturing method of claim 1 or 4 , wherein the atmosphere in which the formation of the natural oxide of copper is suppressed is a reducing atmosphere.
13. The semiconductor device manufacturing method of claim 1 or 4 , wherein the organic acid is carboxylic acid.
14. The semiconductor device manufacturing method of claim 1 or 4 , further comprising, after said heating the substrate, removing an excessive portion of the self-forming barrier metal deposited on the surface of copper.