Films of desired composition and film properties
Provided are methods and systems for providing silicon-containing films. The composition of the silicon-containing film can be controlled by the choice of the combination of precursors and the ratio of flow rates between the precursors. The silicon-containing films can be deposited on a substrate by flowing two different organo-silicon precursors to mix together in a reaction chamber. The organo-silicon precursors react with one or more radicals in a substantially low energy state to form the silicon-containing film. The one or more radicals can be formed in a remote plasma source.
1. A method of depositing a silicon-carbon-containing film, the method comprising:
flowing a first organo-silicon precursor and a second organo-silicon precursor to a substrate in a reaction chamber, wherein each of the first organo-silicon precursor and the second organo-silicon precursor comprises one or both of a silicon-silicon (Si—Si) bond and a silicon-hydrogen (Si—H) bond;
generating hydrogen radicals in a plasma source that is separate from the reaction chamber;
introducing the hydrogen radicals to the substrate in the reaction chamber so that the hydrogen radicals react with the first and second organo-silicon precursors to deposit the silicon-carbon-containing film on the substrate; and
modulating relative atomic concentrations of silicon, carbon, oxygen, and nitrogen in the silicon-carbon-containing film based on at least one of the following: a chemistry of the first organo-silicon precursor, a chemistry of the second organo-silicon precursor, and a ratio of flow rates between the first organo-silicon precursor and the second organo-silicon precursor.
2. The method of claim 1 , wherein the relative atomic concentrations of silicon, carbon, oxygen, and nitrogen in the silicon-carbon-containing film is modulated based on the ratio of flow rates between the first organo-silicon precursor and the second organo-silicon precursor.
3. The method of claim 1 , wherein the relative atomic concentrations of silicon, carbon, oxygen and nitrogen in the silicon-carbon-containing film is modulated to tune at least one of the following film properties: a breakdown voltage, a leakage current, a dielectric constant, a hermeticity, a density, an adhesion to metal surfaces, an intrinsic stress, a Young's modulus, and a hardness.
4. The method of claim 3 , wherein modulating the relative atomic concentrations of silicon, carbon, oxygen, and nitrogen in the silicon-carbon-containing film comprises reducing a carbon concentration in the silicon-carbon-containing film to reduce the dielectric constant of the silicon-carbon-containing film.
5. The method of claim 1 , wherein the first organo-silicon precursor comprises an organo-silicon oxide precursor, and wherein the silicon-carbon-containing film comprises an oxygen-doped silicon carbide film.
6. The method of claim 1 , wherein the first organo-silicon precursor comprises an organo-silicon nitride precursor, and wherein the silicon-carbon-containing film comprises a nitrogen-doped silicon carbide film.
7. The method of claim 1 , wherein the first organo-silicon precursor comprises an organo-silicon oxide precursor and the second organo-silicon precursor comprises an organo-silicon nitride precursor, and wherein the silicon-carbon-containing film comprises an oxygen-doped and nitrogen-doped silicon carbide film.
8. The method of claim 1 , further comprising:
changing a flow rate of the second organo-silicon precursor over time so that the hydrogen radicals react with the first and second organo-silicon precursors to deposit the silicon-carbon-containing film having varying relative atomic concentrations of silicon, carbon, oxygen, and nitrogen across a thickness of the silicon-carbon-containing film.
9. The method of claim 1 , further comprising:
changing a composition of the second organo-silicon precursor over time so that the hydrogen radicals react with the first and second organo-silicon precursors to deposit the silicon-carbon-containing film having varying relative atomic concentrations of silicon, carbon, oxygen, and nitrogen across a thickness of the silicon-carbon-containing film.
10. The method of claim 1 , wherein the first and second organo-silicon precursors are flowed simultaneously together into the reaction chamber.
11. The method of claim 1 , wherein the first and second organo-silicon precursors are flowed sequentially into the reaction chamber.
12. The method of claim 1 , wherein the hydrogen radicals have sufficient energy to break Si—Si bonds and Si—H bonds but preserve Si—O bonds, Si—N bonds, and Si—C bonds.
13. A method of depositing a silicon-carbon-containing film, the method comprising:
flowing an organo-silicon precursor to a substrate in a reaction chamber;
flowing a co-reactant gas to the substrate in the reaction chamber;
generating hydrogen radicals in a plasma source that is separate from the reaction chamber, wherein the hydrogen radicals are generated from a source gas of hydrogen;
introducing the hydrogen radicals to the substrate in the reaction chamber, wherein the co-reactant gas and the hydrogen radicals react with the organo-silicon precursor in an environment adjacent to the substrate; and
changing a flow rate of the co-reactant gas over time, wherein the co-reactant gas and the hydrogen radicals react with the organo-silicon precursor to deposit the silicon-carbon-containing film having a varying composition across a thickness of the silicon-carbon-containing film.
14. The method of claim 13 , wherein the silicon-carbon-containing film has a varying concentration of oxygen and nitrogen between an upper surface and a lower surface of the silicon-carbon-containing film.
15. The method of claim 13 , wherein the hydrogen radicals comprise hydrogen radicals in a ground state in the environment adjacent to the substrate.
16. The method of claim 13 , wherein the environment adjacent to the substrate is free or substantially free of ions and ultraviolet (UV) radiation.
17. The method of claim 13 , wherein the organo-silicon precursor comprises a siloxane.
18. The method of claim 17 , wherein the siloxane comprises pentamethyldisiloxane (PMDSO) or tetramethyldisiloxane (TMDSO).
19. The method of claim 13 , wherein the organo-silicon precursor is flowed into the reaction chamber through a first gas inlet coupled to the reaction chamber and a vessel, and wherein the radicals are introduced into the reaction chamber through a second gas inlet coupled to the reaction chamber and the plasma source.
20. The method of claim 13 , wherein the silicon-carbon-containing film has an effective dielectric constant equal to or less than about 4.0.