Deposition of conformal films by atomic layer deposition and atomic layer etch

Patent metadata

Field	Value
Publication number	US-2016293398-A1
Application number	US-201514678736-A
Country	US
Kind code	A1
Filing date	Apr 3, 2015
Priority date	Apr 3, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Methods for depositing conformal films using a halogen-containing etchant during atomic layer deposition are provided. Methods involve exposing a substrate to a halogen-containing etchant such as nitrogen trifluoride between exposing the substrate to a first precursor and exposing the substrate to a second plasma-activated reactant. Examples of conformal films that may be deposited include silicon-containing films and metal-containing films. Related apparatuses are also provided.

First claim

1 . A method of processing substrates in a chamber, the method comprising:
(a) providing a substrate having one or more features, each feature comprising a feature opening; (b) exposing the substrate to a silicon-containing precursor under conditions allowing the silicon-containing precursor to adsorb onto the surface of the substrate, thereby forming an adsorbed layer of the silicon-containing precursor; (c) after exposing the substrate to the silicon-containing precursor, exposing the substrate to a halogen-containing etchant; and (d) exposing the substrate to a nitrogen-containing reactant and igniting a plasma to selectively etch the adsorbed layer of the silicon-containing precursor at or near the feature openings and form a silicon nitride film.

2 . The method of claim 1 , wherein the substrate is exposed to the halogen-containing etchant under conditions allowing the halogen-containing etchant to selectively adsorb onto the adsorbed layer of the silicon-containing precursor.

3 . The method of claim 1 , wherein the halogen-containing etchant is selected from the group consisting of nitrogen trifluoride, chlorine, fluoroform, carbon tetrafluoride, and combinations thereof.

4 . The method of claim 1 , wherein the halogen-containing etchant comprises a compound with a chemical formula of C n F 2n+2 or C n F 2n , where n>1.

5 . The method of claim 1 , wherein the chamber is purged after exposing the substrate to the halogen-containing etchant.

6 . The method of claim 5 , wherein the chamber is purged by flowing a purge gas selected from the group consisting of argon, helium, nitrogen, and hydrogen.

7 . The method of claim 1 , wherein the silicon-containing precursor is selected from the group consisting of silane, disilane, trisilane, tetrasilane, trisilylamine, aminosilanes, and halosilanes.

8 . The method of claim 1 , wherein the nitrogen-containing reactant is selected from the group consisting of nitrogen, ammonia, hydrazine, and amines.

9 . The method of claim 1 , further comprising repeating (a)-(d).

10 . The method of claim 1 , wherein (a)-(d) are performed in the same chamber.

11 . A method of processing substrates in a chamber, the method comprising:
depositing a film by performing one or more cycles, a cycle comprising: (a) providing a substrate having one or more features, each feature comprising a feature opening; (b) exposing the substrate to a first precursor under conditions allowing the first precursor to adsorb onto the surface of the substrate, thereby forming an adsorbed layer of the first precursor; (c) after exposing the substrate to the first precursor, exposing the substrate to a halogen-containing etchant; and (d) exposing the substrate to a second reactant and igniting a plasma to selectively etch the adsorbed layer of the first precursor at or near the feature openings and form a film.

12 . The method of claim 11 , wherein the halogen-containing etchant is selected from the group consisting of nitrogen trifluoride, chlorine, fluoroform, carbon tetrafluoride, and combinations thereof.

13 . The method of claim 11 , wherein the chamber is purged before (d).

14 . The method of claim 11 , wherein the film is a dielectric or metal film.

15 . The method of claim 11 , wherein the film is selected from the group consisting of silicon nitride, silicon carbide, and silicon oxide.

16 . The method of claim 11 , wherein the second reactant is an oxidant or reductant.

17 . The method of claim 11 , wherein (d) is performed every n cycles, where n is an integer equal to or greater than 1.

18 . An apparatus for processing substrates, the apparatus comprising:
(a) at least one process chamber comprising a pedestal for holding a substrate; (b) at least one outlet for coupling to a vacuum; (c) one or more process gas inlets coupled to one or more silicon-containing precursor sources and one or more halogen-containing etchants; (d) a radio frequency (RF) generator; and (e) a controller for controlling operations in the apparatus, comprising machine-readable instructions for:
(i) introducing a silicon-containing precursor to a process chamber;
(ii) after introducing the silicon-containing precursor, introducing a halogen-containing etchant to the chamber; and
(iii) introducing a nitrogen-containing reactant to the chamber and igniting a plasma to form a silicon nitride film.

19 . The apparatus of claim 18 , wherein the controller further comprises machine-readable instructions for introducing a purge gas prior to introducing the nitrogen-containing reactant to purge the chamber.

20 . The apparatus of claim 18 , wherein the halogen-containing etchant is selected from the group consisting of nitrogen trifluoride, chlorine, fluoroform, carbon tetrafluoride, and combinations thereof.

Assignees

• Lam Res Corp

Inventors

• Danek Michal
• Henri Jon
• Tang Shane

Classifications

• H10P72/0468

  comprising a chamber adapted to a particular process · CPC title

• H10P72/0466

  characterised by the construction of the load-lock chamber · CPC title

• H10P72/0421

  for drying etching · CPC title

• H10P14/69433 Primary

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title

• H10P14/6682

  the compound being a silane, e.g. disilane, methylsilane or chlorosilane · CPC title