Atomic layer deposition of silicon carbon nitride based materials

• US 9,837,263 B2
• Filed: 06/29/2016
• Issued: 12/05/2017
• Est. Priority Date: 12/11/2013
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Pore, Viljami
• Primary Examiner(s): MULPURI, SAVITRI
• Application Number:
  US15/196,985
• Publication Number:
  US 20160307751A1
• Time in Patent Office: 524 Days
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31111 by chemical means

Abstract

A process for depositing a silicon carbon nitride film on a substrate can include a plurality of complete deposition cycles, each complete deposition cycle having a SiN sub-cycle and a SiCN sub-cycle. The SiN sub-cycle can include alternately and sequentially contacting the substrate with a silicon precursor and a SiN sub-cycle nitrogen precursor. The SiCN sub-cycle can include alternately and sequentially contacting the substrate with carbon-containing precursor and a SiCN sub-cycle nitrogen precursor. The SiN sub-cycle and the SiCN sub-cycle can include atomic layer deposition (ALD). The process for depositing the silicon carbon nitride film can include a plasma treatment. The plasma treatment can follow a completed plurality of complete deposition cycles.

Claims

1. A method of treating a silicon carbon nitride film on a three-dimensional structure having a sidewall region and a top region, the method comprising:

exposing the silicon carbon nitride film on the substrate to a hydrogen-containing plasma generated from a reactant gas that comprises hydrogen gas (H₂),

wherein a ratio of a wet etch rate of the sidewall region to a wet etch rate of the top region of the treated silicon carbon nitride film on the three-dimensional structure is less than 3 as measured in a dilute aqueous solution of hydrofluoric acid having a concentration of 0.5 weight %, and

wherein the treated silicon carbon nitride film has a wet etch rate that is less than about 50% of the wet etch rate of thermal silicon oxide, as measured in dilute hydrofluoric acid having a concentration of 0.5 weight %, or has a wet etch rate of less than about 1 nm/min in a dilute aqueous solution of hydrofluoric acid having a concentration of 0.5 weight %.

2. The method of claim 1, wherein the three-dimensional structure has an aspect ratio of six or higher.

3. The method of claim 1, wherein the reactant gas comprises a noble gas.

4. The method of claim 3, wherein the reactant gas comprises N₂, H₂ and Ar.

5. The method of claim 3, wherein the reactant gas consists of hydrogen gas (H₂) and a noble gas.

6. The method of claim 1, wherein the silicon carbon nitride film is exposed to the hydrogen-containing plasma for at least 30 seconds.

7. The method of claim 6, wherein the silicon carbon nitride film is exposed to the hydrogen-containing plasma for at least 10 minutes.

8. The method of claim 1, wherein the hydrogen-containing plasma is generated by applying RF power from about 100 W to about 500 W to the reactant gas.

9. The method of claim 1, wherein the plasma treatment is repeated multiple times.

10. The method of claim 1, wherein exposing the silicon carbon nitride film to the hydrogen-containing plasma comprises a plurality of cycles in which the plasma is turned on for a first duration of time and turned off for a second duration of time.

11. The method of claim 10, wherein the duration in which the plasma is turned on differs in two or more cycles.

12. The method of claim 1, additionally comprising depositing SiN over the treated silicon carbon nitride film.

13. The method of claim 12, wherein the SiN is deposited by atomic layer deposition (ALD) after exposing the silicon carbon nitride film to the hydrogen-containing plasma.

14. The method of claim 13, wherein the atomic layer deposition process comprises at least one silicon nitride deposition cycle comprising alternately and sequentially contacting the substrate with a first silicon precursor and a second nitrogen precursor.

15. The method of claim 12, additionally comprising depositing silicon carbon nitride over the SiN by an atomic layer deposition (ALD) process.

16. The method of claim 15, wherein the ALD process comprises at least one silicon carbon nitride deposition cycle comprising alternately and sequentially contacting the substrate with a first precursor comprising silicon and carbon and a second precursor comprising nitrogen.

17. The method of claim 16, wherein the precursor comprising silicon and carbon comprises a —

Si—

R—

Si—

group, where R comprises a C₁ to C₈ hydrocarbon.

18. The method of claim 16, wherein the precursor comprising silicon and carbon comprises at least one of bis(trichlorosilyl)methane (BTCSMe) and 1,2-bis(trichlorosilyl)ethane (BTCSEt).