Atomic layer deposition of silicon carbon nitride based materials

• US 10,199,211 B2
• Filed: 11/22/2017
• Issued: 02/05/2019
• 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, Savitr
• Application Number:
  US15/820,916
• Publication Number:
  US 20180082838A1
• Time in Patent Office: 440 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 for forming a plasma-treated film on a substrate comprising:

depositing a thin film on the substrate by a plurality of deposition cycles each comprising alternately and sequentially contacting the substrate with a first vapor-phase silicon precursor comprising two silicon atoms bound to a hydrocarbon in an Si—

R—

Si—

structure, where R comprises a C₁ to C₈ hydrocarbon, and a second vapor-phase nitrogen reactant; and

subsequently exposing the substrate to a hydrogen-containing plasma generated from a reactant gas that comprises H₂,

wherein a ratio of a wet etch rate of the plasma-treated film on the sidewall region of a three-dimensional structure to a wet etch rate of the treated thin film on the top region of 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 %.

2. The method of claim 1, wherein the plasma-treated 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 %.

3. The method of claim 1, wherein the plasma-treated film 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 %.

4. The method of claim 1, wherein the plurality of deposition cycles are part of a thermal atomic layer deposition (ALD) process.

5. The process of claim 1, wherein the thin film is deposited at a temperature of 300 to 600°

C.

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

7. The method of claim 6, wherein the reactant gas comprises one or more of N₂, H₂ and Ar.

8. The method of claim 6, wherein the reactant gas consists of hydrogen gas (H₂) and a noble gas.

9. The method of claim 1, wherein the thin film is exposed to the hydrogen-containing plasma for at least 30 seconds.

10. The method of claim 9, wherein the thin film is exposed to the hydrogen-containing plasma for at least 10 minutes.

11. 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.

12. The method of claim 1, wherein exposing the thin 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.

13. The method of claim 12, wherein the duration in which the plasma is turned on differs in two or more cycles.

14. The method of claim 1, wherein the deposited thin film comprises carbon.

15. The method of claim 1, wherein the nitrogen reactant comprises a hydrogen atom bonded to a nitrogen atom.

16. The method of claim 1, wherein the nitrogen reactant is NH₃.

17. The method of claim 1, wherein in the silicon precursor R comprises a C₁ to C₃ alkyl chain.

18. The method of claim 1, wherein the silicon precursor is a halogen substituted silylalkane.

19. The method of claim 1, wherein the silicon precursor comprises an unsubstituted silylalkane.

20. The method of claim 19, wherein the silicon precursor comprises bis(silyl)alkane, tris(silyl)alkane or tetrakis(silyl)alkane.

21. The method of claim 1, wherein the silicon precursor comprises bis(trichlorosilyl)methane (BTCSMe) or 1,2-bis(trichlorosilyl)ethane (BTCSEt).