Flowable dielectric using oxide liner

• US 8,647,992 B2
• Filed: 12/21/2010
• Issued: 02/11/2014
• Est. Priority Date: 01/06/2010
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Liang, Jingmei, Ingle, Nitin K.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): JEFFERSON, QUOVAUNDA
• Application Number:
  US12/974,495
• Publication Number:
  US 20110165781A1
• Time in Patent Office: 1,148 Days
• Field of Search: 438/622, 438/787, 438/791, 438/758, 438/778, 438/786, 438/788, 438/792, 438/FOR.385, 438/FOR.394, 438/FOR.398, 257/E21.271, 257/E21.273, 257/E21.278, 257/E21.292, 257/E21.293
• US Class Current: 438/763
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02326 into a nitride layer, e.g. changing SiN to SiON
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour

Abstract

Methods of forming silicon oxide layers are described. The methods include mixing a carbon-free silicon-containing precursor with a radical-nitrogen precursor, and depositing a silicon-and-nitrogen-containing layer on a substrate. The radical-nitrogen precursor is formed in a plasma by flowing a hydrogen-and-nitrogen-containing precursor into the plasma. Prior to depositing the silicon-and-nitrogen-containing layer, a silicon oxide liner layer is formed to improve adhesion, smoothness and flowability of the silicon-and-nitrogen-containing layer. The silicon-and-nitrogen-containing layer may be converted to a silicon-and-oxygen-containing layer by curing and annealing the film. Methods also include forming a silicon oxide liner layer before applying a spin-on silicon-containing material.

Claims

1. A method of forming a flowable dielectric layer on a substrate, the method comprising the sequential steps of:

forming a generally conformal silicon oxide liner layer on silicon nitride on the substrate by exposing the substrate to a silicon-containing liner precursor and an oxygen-containing liner precursor, wherein the substrate is maintained at a liner deposition temperature;

forming a carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer on the silicon oxide liner layer using radical-component chemical vapor deposition, wherein the substrate is maintained at a bulk deposition temperature, wherein the bulk-deposition temperature is less than 120°

C.;

curing the substrate at a substrate temperature below or about 400°

C. in an ozone-containing atmosphere, and

raising a temperature of the substrate to an oxygen anneal temperature above or about 600°

C. in an oxygen-containing atmosphere.

2. The method of claim 1 wherein forming the carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer comprises:

flowing a nitrogen-and-hydrogen-containing gas into a plasma region to produce a radical-nitrogen precursor;

combining a carbon-free silicon-containing precursor with the radical-nitrogen precursor in a plasma-free substrate processing region; and

depositing a silicon-and-nitrogen-containing layer on the substrate.

3. The method of claim 2 wherein the nitrogen-and-hydrogen-containing gas comprises ammonia (NH₃).

4. The method of claim 2 wherein the nitrogen-and-hydrogen-containing gas comprises at least one of nitrogen (N₂), hydrogen (H₂), hydrazine (N₂H₄) and ammonia (NH₃).

5. The method of claim 1 wherein a thickness of the generally conformal silicon oxide liner is less than or about 100 Å

.

6. The method of claim 2 wherein the carbon-free silicon-containing precursor comprises N(SiH₃)₃.

7. The method of claim 1 wherein the carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer comprises a carbon-free Si—

N—

H layer.

8. The method of claim 1 wherein the bulk-deposition temperature is lower than the liner deposition temperature.

9. The method of claim 1 wherein the oxygen-containing liner precursor comprises oxygen (O₂).

10. The method of claim 1 wherein the liner deposition temperature is greater than 400°

C.

11. The method of claim 1 wherein the silicon-containing liner precursor comprises TEOS.

12. The method of claim 1 wherein the oxygen-containing atmosphere comprises one or more gases selected from the group consisting of atomic oxygen, ozone, and steam (H₂O).

13. The method of claim 2 wherein the plasma region is in a remote plasma system.

14. The method of claim 2 wherein the plasma region is a partitioned portion of the substrate processing chamber separated from the plasma-free substrate processing region by a showerhead.

15. The method of claim 1 wherein the oxygen-containing liner precursor comprises ozone.