TREATMENTS FOR DECREASING ETCH RATES AFTER FLOWABLE DEPOSITION OF SILICON-CARBON-AND-NITROGEN-CONTAINING LAYERS

• US 20130217241A1
• Filed: 08/21/2012
• Published: 08/22/2013
• Est. Priority Date: 09/09/2011
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Underwood, Brian S., Wang, Linlin, Kamath, Sanjay, Mallick, Abhijit Basu, Ingle, Nitin K.
• Application Number:
  US13/590,702
• Publication Number:
  US 20130217241A1
• Time in Patent Office: Days
• US Class Current: 438/778
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02208 the precursor containing a compound comprising Si
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02222 the compound being a silazane
• 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 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02318 post-treatment
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/02351 treatment by exposure to corpuscular radiation, e.g. exposure to electrons, alpha-particles, protons or ions
• CPC Class Codes: H01L 21/31111 by chemical means

Abstract

Methods are described for forming and curing a flowable silicon-carbon-and-nitrogen-containing layer on a semiconductor substrate. The silicon and carbon constituents may come from a silicon and carbon containing precursor while the nitrogen may come from a nitrogen-containing precursor that has been activated to speed the reaction of the nitrogen with the silicon-and-carbon-containing precursor at lower deposition chamber temperatures. The initially-flowable silicon-carbon-and-nitrogen-containing layer is treated to remove components which enabled the flowability, but are no longer needed after deposition. Removal of the components increases etch resistance in order to allow the gapfill silicon-carbon-and-nitrogen-containing layer to remain intact during subsequent processing. The treatments have been found to decrease the evolution of properties of the film upon exposure to atmosphere.

Claims

1. A method of forming a silicon-carbon-and-nitrogen-containing layer on a semiconductor substrate, the method comprising:

forming an as-deposited silicon-carbon-and-nitrogen-containing layer on the semiconductor substrate, wherein the silicon-carbon-and-nitrogen-containing layer is initially flowable during deposition; and

treating the as-deposited silicon-carbon-and-nitrogen-containing layer to form an etch resistant silicon-carbon-and-nitrogen-containing layer, wherein the etch resistance of the etch resistant silicon-carbon-and-nitrogen-containing layer exceeds that of the as-deposited silicon-carbon-and-nitrogen-containing layer.

2. The method of claim 1, wherein the as-deposited silicon-carbon-and-nitrogen-containing layer comprises Si—

H bonds.

3. The method of claim 2, wherein the treating of the flowable silicon-carbon-and-nitrogen-containing layer reduces the number of Si—

H bonds in the material.

4. The method of claim 1, wherein treating the as-deposited silicon-carbon-and-nitrogen-containing layer comprises exposing the material to a plasma.

5. The method of claim 4, wherein the plasma for treating the as-deposited silicon-carbon-and-nitrogen-containing layer is located in the chemical vapor deposition chamber.

6. The method of claim 4, wherein the plasma for treating the as-deposited silicon-carbon-and-nitrogen-containing layer is an inductively-coupled plasma or a capacitively-coupled plasma.

7. The method of claim 4, wherein the plasma for treating the as-deposited silicon-carbon-and-nitrogen-containing layer is a high density plasma.

8. The method of claim 4, wherein the plasma for treating the as-deposited silicon-carbon-and-nitrogen-containing layer is formed from at least one of helium, argon, nitrogen or neon.

9. The method of claim 4, wherein the plasma has an ion density greater than or about 10¹¹ ions/cm³.

10. The method of claim 1, wherein treating the as-deposited silicon-carbon-and-nitrogen-containing layer comprises at least one of exposing the layer to a high-density plasma, exposing the material to an electron beam, exposing the material to UV light, or heating the semiconductor substrate.

11. The method of claim 1, wherein forming the as-deposited silicon-carbon-and-nitrogen-containing layer comprises:

flowing a silicon-containing precursor to a substrate processing region;

flowing a nitrogen-containing precursor into a remote plasma region to form plasma effluents;

flowing the plasma effluents into the substrate processing region; and

reacting the silicon-containing precursor and the energized nitrogen-containing precursor in the chemical vapor deposition chamber to form the as-deposited silicon-carbon-and-nitrogen-containing layer on the semiconductor substrate.

12. The method of claim 11, wherein the silicon-containing precursor comprises disilacyclobutane, trisilacyclohexane, 3-methylsilane, silacyclopentene, silacyclobutene, 1,3,5-trisilapentane, 1,4,7-trisilaheptane, or trimethylsilylacetylene.

13. The method of claim 11, wherein the nitrogen-containing precursor comprises ammonia.

14. The method of claim 11, wherein the substrate processing region and the remote plasma region are compartments within a deposition chamber and the substrate processing region is separated from the substrate processing region by a showerhead.

15. A method of forming a silicon-carbon-and-nitrogen-containing layer on a semiconductor substrate, the method comprising:

forming an as-deposited silicon-carbon-and-nitrogen-containing layer on the semiconductor substrate, wherein the silicon-carbon-and-nitrogen-containing layer is initially flowable during deposition; and

exposing the as-deposited silicon-carbon-and-nitrogen-containing layer to a high density plasma to form an etch resistant silicon-carbon-and-nitrogen-containing layer, wherein the etch resistance of the etch resistant silicon-carbon-and-nitrogen-containing layer exceeds that of the as-deposited silicon-carbon-and-nitrogen-containing layer.

16. The method of claim 15, wherein the flowable silicon-containing precursor comprises disilacyclobutane, trisilacyclohexane, 3-methylsilane, silacyclopentene, silacyclobutene, 1,3,5-trisilapentane, 1,4,7-trisilaheptane, or trimethylsilylacetylene.

17. The method of claim 15, wherein the temperature of the semiconductor substrate during the exposing operation is about 300°

C. or less.

18. The method of claim 15, wherein the total source RF plasma power may be greater than or about 2000 Watts.

19. The method of claim 15, wherein a thickness of the treated silicon-carbon-and-nitrogen-containing layer is greater than or about 25 Å

in relatively open areas.

20. The method of claim 15, wherein the etch rate of the treated silicon-carbon-and-nitrogen-containing layer is about 15 Å

/min or less in a hot phosphoric acid solution.

21. The method of claim 15, wherein the etch rate of the treated silicon-carbon-and-nitrogen-containing layer is about 15 Å

/min or less in a buffered oxide etch solution.