Conformal deposition of silicon carbide films
Disclosed are methods and systems for providing silicon carbide films. A layer of silicon carbide can be provided under process conditions that employ one or more silicon-containing precursors that have one or more silicon-hydrogen bonds and/or silicon-silicon bonds. The silicon-containing precursors may also have one or more silicon-oxygen bonds and/or silicon-carbon bonds. One or more radical species in a substantially low energy state can react with the silicon-containing precursors to form the silicon carbide film. The one or more radical species can be formed in a remote plasma source.
1. A method of depositing a silicon carbide film on a substrate, the method comprising:
(a) providing the substrate to a reaction chamber;
(b) flowing one or more silicon-containing precursors to the substrate, wherein each of the one or more silicon-containing precursors have (i) one or more silicon-hydrogen bonds and/or silicon-silicon bonds, (ii) one or more silicon-carbon bonds, silicon-nitrogen bonds, and/or silicon-oxygen bonds, (iii) no carbon-oxygen bonds, and (iv) no carbon-nitrogen bonds;
(c) flowing a source gas and a first co-reactant into a plasma source, wherein the source gas comprises hydrogen and the first co-reactant comprises an oxygen-containing species that does not contain silicon;
(d) generating, from the source gas and the first co-reactant, radicals of hydrogen and radicals of oxygen in the plasma source;
(e) flowing the radicals of hydrogen onto the substrate, wherein all or at least 90% of the radicals of hydrogen are radicals of hydrogen in the ground state that react with the one or more silicon-containing precursors under conditions that break the silicon-containing precursor's silicon-hydrogen bonds or silicon-silicon bonds but preserve the silicon-containing precursor's silicon-carbon bonds, silicon-nitrogen bonds, and/or silicon-oxygen bonds; and
(f) forming, from the reaction, a silicon oxycarbide (SiOC) film, silicon nitricarbide (SiNC) film, or silicon oxynitricarbide (SiONC) film on the substrate, wherein the one or more silicon-containing precursors include an alkylcarbosilane, a siloxane, a silazane, or any combination thereof when forming SiOC film, SiNC film, or SiONC film, wherein the SiOC film, SiNC film, or SiONC film has a conformality of at least 90%.
2. The method of claim 1 , wherein oxygen-containing species includes carbon dioxide, carbon monoxide, water, methanol, oxygen, ozone, or combinations thereof.
3. The method of claim 1 , wherein oxygen-containing species includes oxygen.
4. The method of claim 3 , wherein a ratio between the flow rate of hydrogen and a flow rate of oxygen is between 40:1 and 100:1.
5. The method of claim 3 , wherein a ratio between the flow rate of hydrogen and a flow rate of oxygen is between 40:1 and 200:1.
6. The method of claim 3 , wherein a ratio between the flow rate of hydrogen and a flow rate of oxygen is between 100:1 and 500:1.
7. The method of claim 3 , wherein a ratio between the flow rate of hydrogen and a flow rate of oxygen is between 200:1 and 500:1.
8. The method of claim 1 , further comprising generating, from the first co-reactant, radicals of oxygen in the plasma source.
9. The method of claim 8 , wherein generating the radicals of hydrogen and generating the radicals of oxygen comprises exposing the source gas and first co-reactant to a remote plasma.
10. The method of claim 1 , further comprising flowing a second co-reactant with the one or more silicon-containing precursors, wherein the second co-reactant includes carbon dioxide, carbon monoxide, water, methanol, oxygen, ozone, nitrogen, nitrous oxide, ammonia, methane, ethane, acetylene, ethylene, diborane, or combinations thereof.
11. The method of claim 10 , wherein the second co-reactant includes one or both of carbon dioxide and oxygen.
12. The method of claim 1 , wherein the silicon oxycarbide film, silicon nitricarbide film, or silicon oxynitricarbide film is formed without performing atomic layer deposition.
13. The method of claim 1 , wherein the one or more silicon containing precursors have no alkoxy groups (—C—O—R), where R is an organic moiety, and no amine groups (—C—NR1R2), where R1 and R2 are each independently hydrogen or an organic moiety.
14. The method of claim 1 , wherein the one or more silicon-containing precursors include a cyclic siloxane.
15. The method of claim 14 , wherein the cyclic siloxane is selected from the group consisting of heptamethylcyclotetrasiloxane and tetramethylcyclotetrasiloxane.
16. The method of claim 1 , wherein the one or more silicon containing precursors include a linear siloxane.
17. The method of claim 16 , wherein the linear siloxane is selected from the group consisting of disiloxanes and trisiloxanes.
18. The method of claim 1 , wherein the one or more silicon-containing precursors include an alkyl silane.
19. The method of claim 1 , wherein the one or more silicon-containing precursors include a silazane.
20. The method of claim 1 , wherein during (b) through (e), no compound containing a carbon-oxygen bond or a carbon-nitrogen bond is provided to the substrate.