DEPOSITION OF CONFORMAL FILMS BY ATOMIC LAYER DEPOSITION AND ATOMIC LAYER ETCH

• US 20160293398A1
• Filed: 04/03/2015
• Published: 10/06/2016
• Est. Priority Date: 04/03/2015
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Danek, Michal, Henri, Jon, Tang, Shane
• Granted Patent: US 9,502,238 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: H01J 2237/332 Coating
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67201 characterized by the construction of the load-lock chamber
• CPC Class Codes: H01L 21/67207 comprising a chamber adapted to a particular process

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.

Claims

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_nF_2n+2 or C_nF_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.