Fluorination during ALD high-k, fluorination post high-k and use of a post fluorination anneal to engineer fluorine bonding and incorporation
Embodiments of the present disclosure generally relate to methods for forming a high-k gate dielectric in a transistor. The high-k gate dielectric may be formed by introducing a fluorine containing gas into a processing chamber during the deposition of the high-k gate dielectric in the processing chamber. In one embodiment, the high-k gate dielectric is formed by an ALD process in a processing chamber, and a fluorine containing gas is introduced into the processing chamber during one or more stages of the ALD process. Fluorine ions, molecules or radicals from the fluorine containing gas (may be activated by a plasma) can fill the oxygen vacancies in the high-k dielectric.
1. A method, comprising:
flowing a first precursor into a processing chamber;
exposing a substrate to the first precursor to form a monolayer containing the first precursor on the substrate disposed in the processing chamber; then
flowing a second precursor into the processing chamber;
exposing the substrate to the second precursor to react the second precursor with the first precursor of the monolayer and form a dielectric layer on the substrate;
sequentially repeating exposing the substrate to the first and second precursors to grow the dielectric layer to a predetermined thickness; and
exposing the substrate to a fluorine containing gas while growing the dielectric layer and incorporating fluorine into the dielectric layer, wherein the substrate is exposed to the fluorine containing gas between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber.
2. The method of claim 1 , wherein the dielectric layer having the predetermined thickness is a fluorinated high-k dielectric.
3. The method of claim 2 , wherein the dielectric layer having the predetermined thickness is fluorinated hafnium oxide.
4. The method of claim 1 , wherein the first precursor comprises hafnium, zirconium, titanium, tantalum, lanthanum, aluminum, or silicon.
5. The method of claim 4 , wherein the fluorine containing gas comprises fluorine gas, tetrafluoromethane, or nitrogen trifluoride.
6. The method of claim 1 , further comprising flowing a third precursor into the processing chamber, and the dielectric layer is formed by reacting the third precursor with a reaction product of the second precursor and the monolayer, and the fluorine containing gas is introduced into the processing chamber between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber, between flowing the second precursor into the processing chamber and flowing the third precursor into the processing chamber, and between flowing the third precursor into the processing chamber and flowing the first precursor into the processing chamber.
7. The method of claim 1 , wherein the predetermined thickness of the dielectric layer is about 20 Å to about 40 Å.
8. A method, comprising:
flowing a first precursor into a processing chamber containing a substrate;
exposing the substrate to the first precursor to form a monolayer containing the first precursor on the substrate; then
flowing a second precursor into the processing chamber;
exposing the substrate to the second precursor to react the second precursor with the first precursor of the monolayer and form a dielectric layer on the substrate;
sequentially repeating exposing the substrate to the first and second precursors to grow the dielectric layer to a predetermined thickness; and
exposing the substrate to a fluorine containing plasma while growing the dielectric layer and incorporating fluorine into the dielectric layer, wherein the substrate is exposed to the fluorine containing plasma between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber.
9. The method of claim 8 , wherein the first precursor comprises hafnium, zirconium, titanium, tantalum, lanthanum, aluminum or silicon.
10. The method of claim 8 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a processing region of the processing chamber and activating the fluorine containing gas in the processing region, wherein the fluorine containing gas comprises fluorine gas, tetrafluoromethane, or nitrogen trifluoride.
11. The method of claim 8 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a remote plasma source of the processing chamber and activating the fluorine containing gas in the remote plasma source, wherein the fluorine containing gas comprises fluorine gas, tetrafluoromethane, or nitrogen trifluoride.
12. The method of claim 8 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a processing region of the processing chamber between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber and activating the fluorine containing gas in the processing region.
13. The method of claim 8 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a remote plasma source of the processing chamber between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber and activating the fluorine containing gas in the remote plasma source.
14. The method of claim 8 , further comprising flowing a third precursor into the processing chamber.
15. The method of claim 14 , wherein the dielectric layer is formed by reacting the third precursor with a reaction product of the second precursor and the monolayer.
16. The method of claim 15 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a processing region of the processing chamber between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber, between flowing the second precursor into the processing chamber and flowing the third precursor into the processing chamber, and between flowing the third precursor into the processing chamber and flowing the first precursor into the processing chamber, wherein the fluorine containing gas is activated in the processing region.
17. The method of claim 15 , wherein the fluorine containing plasma is formed by flowing a fluorine containing gas into a remote plasma source of the processing chamber between flowing the first precursor into the processing chamber and flowing the second precursor into the processing chamber, between flowing the second precursor into the processing chamber and flowing the third precursor into the processing chamber, and between flowing the third precursor into the processing chamber and flowing the first precursor into the processing chamber, wherein the fluorine containing gas is activated in the remote plasma source and the fluorine containing plasma is flowed from the remote plasma source to a processing region of the processing chamber.
18. The method of claim 8 , wherein the predetermined thickness of the dielectric layer is about 20 Å to about 40 Å.
19. A method, comprising:
repeating a cycle during an atomic layer deposition process to form a dielectric layer on a substrate within a processing chamber, wherein the cycle comprises:
exposing the substrate to a first precursor to form a monolayer of the first precursor on the substrate; then
exposing the substrate to a second precursor to react the second precursor with the first precursor of the monolayer and form a dielectric layer on the substrate; and
sequentially repeating exposing the substrate to the first and second precursors to form the dielectric layer to a predetermined thickness; and
exposing the substrate to a fluorine containing gas between exposing the substrate to the first precursor and exposing the substrate to the second precursor, wherein the fluorine containing gas is different than the first and second precursors.
20. The method of claim 19 , wherein the fluorine containing gas comprises fluorine gas, tetrafluoromethane, or nitrogen trifluoride.