Tungsten deposition without barrier layer
Methods for depositing a metal film without the use of a barrier layer are disclosed. Some embodiments comprise forming an amorphous nucleation layer comprising one or more of silicon or boron and forming a metal layer on the nucleation layer.
1. A processing method comprising:
exposing a substrate surface to a boron precursor to form an amorphous boron layer, the substrate surface being substantially free of a barrier layer;
exposing the amorphous boron layer to a first metal precursor to convert the amorphous boron layer to a first metal layer; and
forming a second metal layer on the first metal layer by exposing the first metal layer to a second metal precursor.
2. The method of claim 1 , wherein the boron precursor comprises one or more of a borane, an alkyl borane or a haloborane.
3. The method of claim 1 , wherein the boron precursor comprises one or more species with a general formula of B c H d X e R f , where each X is a halogen independently selected from F, Cl, Br and I, each R is an independently selected C1-C4 alkyl group, c is any integer greater than or equal to 2, each of d, e and f are less than or equal to c+2 and d+e+f is equal to c+2.
4. The method of claim 1 , wherein the amorphous boron layer forms a continuous layer.
5. The method of claim 1 , wherein the amorphous boron layer forms a conformal layer.
6. The method of claim 1 , wherein the amorphous boron layer has a thickness less than or equal to about 50 Å.
7. The method of claim 1 , wherein the first metal precursor and the second metal precursor independently comprise one or more of WF 6 , WCl 6 , WCl 5 , MoF 6 , MoCl 5 , or Mo(CO) 6 .
8. The method of claim 1 , wherein the first metal precursor comprises substantially no fluorine.
9. The method of claim 1 , wherein the first metal precursor and the second metal precursor comprise the same metal.
10. The method of claim 1 , wherein the second metal layer is formed by separately exposing the substrate surface to a second metal precursor and a reactant.
11. A processing method comprising:
exposing a substrate surface to a silicon precursor to form an amorphous silicon layer, the substrate surface being substantially free of a barrier layer;
exposing the amorphous silicon layer to a first metal precursor to convert the amorphous silicon layer to a first metal layer; and
forming a second metal layer on the first metal layer by exposing the first metal layer to a second metal precursor.
12. The method of claim 11 , wherein the silicon precursor comprises one or more of a polysilane or a halosilane.
13. The method of claim 11 , wherein the silicon precursor comprises one or more species with a general formula of Si g H h X i , where each X is a halogen independently selected from F, Cl, Br and I, g is any integer greater than or equal to 1, h and i are each less than or equal to 2g+2 and h+i is equal to 2g+2.
14. The method of claim 11 , wherein the amorphous silicon layer forms a continuous layer.
15. The method of claim 11 , wherein the amorphous silicon layer forms a conformal layer.
16. The method of claim 11 , wherein the amorphous silicon layer has a thickness less than or equal to about 50 Å.
17. The method of claim 11 , wherein the first metal precursor and the second metal precursor independently comprise one or more of WF 6 , WCl 6 , WCl 5 , MoF 6 , MoCl 5 , or Mo(CO) 6 .
18. The method of claim 11 , wherein the first metal precursor comprises substantially no fluorine.
19. The method of claim 11 , wherein the first metal precursor and the second metal precursor comprise the same metal.
20. The method of claim 11 , wherein the second metal layer is formed by separately exposing the substrate surface to a second metal precursor and a reactant.