Atomic layer deposition of silicon carbon nitride based materials

• US 9,401,273 B2
• Filed: 12/10/2014
• Issued: 07/26/2016
• 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:
  US14/566,491
• Publication Number:
  US 20150162185A1
• Time in Patent Office: 594 Days
• Field of Search: 438/786
• US Class Current: 1/1
• 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 process for depositing a silicon carbon nitride film on a substrate in a reaction space, the process comprising a plurality of complete deposition cycles, each complete deposition cycle comprising:

performing a SiN sub-cycle, wherein the SiN sub-cycle forms silicon nitride on the substrate, and wherein the SiN sub-cycle comprises alternately and sequentially contacting the substrate with a silicon precursor and a SiN sub-cycle nitrogen precursor to form the silicon nitride on the substrate;

performing a SiCN sub-cycle, wherein the SiCN sub-cycle forms silicon carbon nitride on the substrate, and wherein the SiCN sub-cycle comprises alternately and sequentially contacting the substrate with a precursor comprising silicon and carbon and a SiCN sub-cycle nitrogen precursor to form the silicon carbon nitride on the substrate; and

purging the reaction space, or removing at least one of excess precursors and reaction byproducts from the reaction space, after at least one of contacting the substrate with the silicon precursor, contacting the substrate with the SiN sub-cycle nitrogen precursor, contacting the substrate with the precursor comprising silicon and carbon and contacting the substrate with the SiCN sub-cycle nitrogen precursor.

2. The process of claim 1, further comprising exposing the silicon carbon nitride film to a plasma treatment.

3. The process of claim 2, wherein the plasma treatment follows completion of one or more of the plurality of complete deposition cycles.

4. The process of claim 2, wherein a reactant gas of the plasma treatment comprises at least one of hydrogen gas (H₂), nitrogen gas (N₂) and argon (Ar).

5. The process of claim 2, wherein the plasma treatment is performed for a duration of at least 10 minutes.

6. The process of claim 2, wherein the plasma treatment can be repeated a number of times.

7. The process of claim 1, wherein the SiCN sub-cycle and the SiN sub-cycle are carried out at a ratio of at least 2 in at least one of the plurality of complete-cycles.

8. The process of claim 1, wherein the SiN sub-cycle and the SiCN sub-cycle comprise an atomic layer deposition (ALD) process.

9. The process of claim 1, wherein at least one of the SiN sub-cycle nitrogen precursor and the SiCN sub-cycle nitrogen precursor comprises ammonia (NH₃).

10. The process of claim 1, wherein the precursor comprising silicon and carbon comprises a —

Si—

R—

Si—

group, wherein R comprises a C₁-C₈ hydrocarbon.

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

12. A process for forming a silicon carbon nitride film, comprising:

depositing the silicon carbon nitride film on a substrate, wherein depositing the silicon carbon nitride film comprises;

performing at least one SiCN deposition cycle, the at least one SiCN deposition cycle including alternately and sequentially contacting the substrate with a precursor comprising silicon and carbon and a SiCN deposition cycle nitrogen precursor; and

performing a SiN deposition cycle, the SiN deposition cycle including alternately and sequentially contacting the substrate with a silicon precursor and a SiN deposition cycle nitrogen precursor;

exposing the silicon carbon nitride film to a hydrogen-containing plasma,

wherein the silicon carbon nitride film is formed over a three-dimensional structure having a sidewall region and a top region, and

wherein subsequent to exposing the silicon carbon nitride film to the hydrogen-containing plasma, a ratio of a wet etch rate of the sidewall region to a wet etch rate of the top region of the silicon carbon nitride film is less than 3 in a dilute aqueous solution of hydrofluoric acid having a concentration of 0.5 weight %.

13. The process of claim 12, wherein the precursor comprising silicon and carbon comprises a —

Si—

R—

Si—

group, wherein R comprises a C₁-C₈ hydrocarbon.

14. The process of claim 12, further comprising exposing the silicon carbon nitride film to the hydrogen-containing plasma between the at least one SiCN deposition cycle and the SiN deposition cycle.

15. The process of claim 12, wherein exposing the silicon carbon nitride film to the hydrogen-containing plasma comprises a plurality of cycles, wherein each of the plurality of cycles comprises a sequence of plasma on and plasma off.

16. The process of claim 12, wherein a reactant gas for the hydrogen-containing plasma consists of hydrogen gas (H₂) and a noble gas.

17. The process of claim 12, wherein exposing the silicon carbon nitride film to the hydrogen-containing plasma is performed for a duration of at least 10 minutes.