Soft landing nanolaminates for advanced patterning
Methods for depositing nanolaminate protective layers over a core layer to enable deposition of high quality conformal films over the core layer for use in advanced multiple patterning schemes are provided. In certain embodiments, the methods involve depositing a thin silicon oxide or titanium oxide film using plasma-based atomic layer deposition techniques with a low high frequency radio frequency (HFRF) plasma power, followed by depositing a conformal titanium oxide film or spacer with a high HFRF plasma power.
1. A method of processing a substrate, the method comprising:
depositing a core layer;
depositing a nanolaminate layer on the core layer; and
depositing a metal nitride or metal oxide layer on the nanolaminate layer,
wherein the nanolaminate layer comprises a stack comprising two or more sublayers, and
wherein the nanolaminate layer comprises silicon oxide or titanium oxide.
2. The method of claim 1 , wherein the core layer is a patterned layer.
3. The method of claim 1 , wherein the core layer comprises amorphous carbon or a photoresist.
4. The method of claim 1 , wherein each of the more than one layer of the nanolaminate layer is deposited using plasma enhanced atomic layer deposition (PEALD) by:
exposing the substrate to a titanium-containing precursor or a silicon-containing precursor;
exposing the substrate to an oxidant; and
initiating a plasma while the substrate is exposed to the oxidant.
5. The method of claim 1 , wherein the metal nitride or metal oxide layer comprises titanium oxide or silicon oxide.
6. The method of claim 1 , wherein the metal nitride or metal oxide layer has etch selectivity to the core layer.
7. The method of claim 1 , wherein the each of the two or more sublayers of the nanolaminate layer comprises silicon oxide or titanium oxide.
8. A method of processing a substrate, the method comprising:
depositing a core layer;
depositing a nanolaminate layer on the core layer; and
depositing a metal nitride or metal oxide layer on the nanolaminate layer,
wherein the metal nitride or metal oxide layer is deposited using a metal-containing precursor by plasma enhance atomic layer deposition (PEALD),
wherein the nanolaminate layer comprises a stack comprising two or more sublayers.
9. The method of claim 8 , wherein the metal-containing precursor is a titanium-containing precursor or a silicon-containing precursor and the PEALD is performed by exposing the substrate to the titanium-containing precursor or the silicon-containing precursor;
exposing the substrate to an oxidant; and
initiating a plasma while the substrate is exposed to the oxidant.
10. The method of claim 9 , wherein the nanolaminate layer is deposited at a temperature between about 50° C. and about 150° C. and the plasma is initiated with HFRF power per square millimeter of substrate area between about 1.768 ×10 −4 W per mm 2 and about 1.768 ×10 −3 W per mm 2 .
11. The method of claim 9 , wherein the nanolaminate layer is deposited at a temperature less than about 100° C.
12. The method of claim 8 , wherein the metal nitride or metal oxide layer deposited using the metal-containing precursor by PEALD is performed by exposing the substrate to the metal-containing precursor; exposing the substrate to an oxidant; and initiating a plasma while the substrate is exposed to the oxidant at a HFRF power per square millimeter of substrate area of at least about 1.768×10 −3 W per mm 2 .
13. The method of claim 8 , wherein the two or more sublayers have different compositions.
14. A method of patterning a semiconductor substrate, the method comprising:
prior to depositing a conformal film on a core layer, depositing a nanolaminate protective layer on a patterned core layer;
depositing a conformal film on the nanolaminate protective layer;
planarizing the conformal film to expose the patterned core layer; and
selectively etching the patterned core layer to form a mask.
15. The method of claim 14 , wherein the patterned core layer comprises amorphous carbon.
16. The method of claim 14 , wherein the nanolaminate protective layer comprises silicon oxide or titanium oxide.
17. The method of claim 14 , wherein the nanolaminate protective layer is deposited using plasma enhanced atomic layer deposition (PEALD) by exposing the semiconductor substrate to a titanium-containing precursor or a silicon-containing precursor; exposing the semiconductor substrate to an oxidant; and initiating a first plasma while the semiconductor substrate is exposed to the oxidant.
18. The method of claim 17 , wherein the nanolaminate protective layer is deposited at a temperature less than about 100° C.
19. The method of claim 17 , wherein the nanolaminate protective layer is deposited at a temperature between about 50° C. and about 150° C. and the first plasma is initiated at a HFRF power per square millimeter of substrate area between about 1.768×10-4 per mm 2 and about 1.768×10-3 per mm 2 .
20. The method of claim 17 , wherein the conformal film is deposited using PEALD by exposing the semiconductor substrate to a titanium-containing precursor; exposing the semiconductor substrate to an oxidant; and initiating a second plasma while the semiconductor substrate is exposed to the oxidant at a HFRF power per square millimeter of substrate area of at least about 1.768×10 −3 W per mm2.