Method and system for etching high-k dielectric materials
A system and a method to remove a layer of high-k dielectric material during the manufacturing of an integrated circuit. In one embodiment of the invention, an etch reactant is employed to form volatile etch products when reacted with high-k layers. Alternately, high-k layers can be anisotropically etched of in accordance with a patterned photoresist or hard mask, where a hyperthermal beam of neutral atoms is used to aid in the reaction of an etch reactant with a high-k layer. Alternately, a hyperthermal beam of neutral atoms or a plasma treatment can used to modify a high-k layer, and subsequently etch the modified high-k layer utilizing an etch reactant that reacts with the modified high-k layer. In still another embodiment of the invention, the hyperthermal beam of neutral atoms is used to etch a high-k layer through physical bombardment of the high-k layer.
1. A method of processing a layer containing a high-permittivity material, the method comprising:
modifying a layer containing a high-permittivity material by exposing the layer to a first process gas in a plasma; and
etching the modified high-permittivity layer in the absence of a plasma by exposing the layer to a second process gas comprising an etch reactant.
2. The method according to claim 1 , wherein the layer containing a high-permittivity material overlies another layer in a substrate.
3. The method according to claim 2 , farther comprising providing the substrate in a process chamber.
4. The method as claimed in claim 1 , wherein the modifying step partially removes the layer containing the high-permittivity material.
5. The method as claimed in claim 1 , wherein the modifying step partially disassociates the layer containing the high-permittivity material.
6. The method according to claim 1 , wherein the first process gas comprises a reactive gas.
7. The method according to claim 4 , wherein the reactive gas comprises at least one of HBr and HCI.
8. The method according to claim 6 , wherein the first process gas further comprises an inert gas.
9. The method according to claim 8 , wherein the inert gas is selected from He, Ne, Ar, Kr, Xe, and N 2 , or mixtures thereof.
10. The method according to claim 1 , wherein the first process gas comprises an inert gas.
11. The method according to claim 10 , wherein the inert gas comprises at least one of He, Ne, Ar, Kr, Xe, and N 2 .
12. The method according to claim 1 , wherein the high-permittivity material comprises at least one of Ta 2 O s , TiO 2 , ZrO 2 , A 1 2 O 3 , HfSiO, and HfO 2 .
13. The method according to claim 12 , wherein the high-permittivity material comprises HfO 2 .
14. The method according to claim 1 , wherein the etch reactant comprises a β-diketone.
15. The method according to claim 14 , wherein the β-diketone comprises at least one of acacH, ifacH, and hfacH.
16. The method according to claim 15 , wherein the β-diketone comprises hfacH.
17. The method according to claim 1 , wherein the second process gas further comprises an inert gas.
18. The method according to claim 17 , wherein the inert gas comprises at least one of He, Ne, Ar, Kr, Xc, and N 2 .
19. The method according to claim 1 , wherein the second process gas further comprises an oxygen-containing gas.
20. The method according to claim 19 , wherein the oxygen-containing gas comprises at least one of O 2 , H 2 O, and H 2 O 2 .
21. The method according to claim 3 , further comprising modifying the substrate temperature at less than about 400° C.
22. The method according to claim 3 , further comprising modifying the substrate temperature at less than about 200° C.
23. The method according to claim 1 , wherein the modifying and the etching are carried out in the same process chamber.
24. The method according to claims 1 , wherein the modifying and the etching are carried out in different process chambers.
25. The method according to claim 1 , further comprising modifying a flow rate of the second process gas at less than 2000 sccm.
26. The method according to claim 14 , further comprising modifying a flow rate of a β-diketone-containing carrier gas at less than 1000 sccm.
27. The method according to claim 1 , further comprising modifying a flow rate of the etch reactant at less than 1000 sccm.
28. The method according to claim 3 , wherein the process chamber has a chamber pressure less than 10 Torr.
29. The method according to claim 23 , wherein the process chamber has a chamber pressure less than 10 Torr.
30. The method according to claim 24 , wherein at least one of the process chambers has a chamber pressure less than 10 Torr.