METHODS AND APPARATUS FOR FORMING FLOWABLE DIELECTRIC FILMS HAVING LOW POROSITY

• US 20150118863A1
• Filed: 10/21/2014
• Published: 04/30/2015
• Est. Priority Date: 10/25/2013
• Status: Abandoned Application

• Current Assignee: Lam Research Corporation, Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Lam Research Corporation
• Inventors: Padhi, Deenesh, Draeger, Nerissa, Ashtiani, Kaihan, Rathod, Megha, van Schravendijk, Bart J.
• Application Number:
  US14/519,712
• Publication Number:
  US 20150118863A1
• Time in Patent Office: Days
• US Class Current: 438/778
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45574 Nozzles for more than one gas
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02315 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/67103 mainly by conduction
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/68742 characterised by a lifting arrangement, e.g. lift pins
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76837 Filling up the space between adjacent conductive structures; Gap-filling properties of dielectrics

Abstract

Provided herein are methods and apparatus for forming flowable dielectric films having low porosity. In some embodiments, the methods involve plasma post-treatments of flowable dielectric films. The treatments can involve exposing a flowable film to a plasma while the film is still in a flowable, reactive state but after deposition of new material has ceased.

Claims

1. A method of depositing a flowable dielectric film in a gap on a substrate, comprising:

introducing a dielectric precursor and a co-reactant to a deposition chamber housing the substrate under conditions such that a flowable film forms in the gap via a non-plasma-assisted condensation reaction;

after forming the flowable film, and while the film is still in a flowable state, stopping a flow of the dielectric precursor to the deposition chamber and exposing the flowable film to a plasma in the deposition chamber.

2. The method of claim 1, wherein the plasma is generated from a process gas including one or more of hydrogen (H₂), helium (He), nitrogen (N₂) and argon (Ar).

3. The method of claim 1, wherein exposure to the plasma furthers condensation of the flowable film.

4. The method of claim 1, wherein exposure to the plasma increases cross-linking of the flowable film.

5. The method of claim 1, wherein the plasma is generated from a non-oxidizing process gas.

6. The method of claim 1, wherein the co-reactant is an oxidant.

7. The method of claim 1, wherein the co-reactant is nitridizing agent.

8. The method of claim 1, wherein the exposing the flowable film to a plasma is performed no more than 30 seconds after stopping the flow of the dielectric precursor.

9. The method of claim 1, wherein the wherein exposing the flowable film to a plasma is performed no more than 15 seconds after stopping the flow of the dielectric precursor.

10. A method of depositing a flowable dielectric film in a gap on a substrate, comprising:

flowing a dielectric precursor and a co-reactant to a deposition chamber housing the substrate at substrate temperature of between about −

20°

C. and 100°

C. to thereby form a flowable film in the gap;

turning off the flow of the dielectric precursor;

immediately after turning off the flow the dielectric precursor, introducing plasma species to the deposition chamber to thereby expose the flowable film to the plasma species, wherein the substrate temperature is maintained at the deposition temperature.

11. The method of claim 10, further comprising performing a cure operation.

12. The method of claim 11, wherein the cure operation is performed at a substrate temperature at least about 100°

C. greater than the deposition temperature.

13. An apparatus comprising:

a chamber including a substrate support;

a plasma generator configured to produce plasma species;

one or more inlets to the chamber; and

a controller comprising instructions for;

a first operation of introducing a dielectric precursor and a co-reactant to the chamber via the one or more inlets at substrate support temperature of between about −

20°

C. and 100°

C. to thereby form a flowable film;

shutting off a flow of the dielectric precursor; and

introducing a process gas to the plasma generator no more than 30 seconds after shutting off the dielectric precursor.

14. The apparatus of claim 13, wherein the controller comprises instructions for introducing the process gas to the plasma generator no more than 15 seconds after shutting off the dielectric precursor.

15. The apparatus of claim 13, wherein the controller comprises instructions for introducing the process gas to the plasma generator immediately after shutting off the dielectric precursor.

16. The apparatus of claim 13, wherein the process gas comprises hydrogen (H₂).