Si precursors for deposition of SiN at low temperatures

Patent metadata

Field	Value
Publication number	US-9905416-B2
Application number	US-201715414485-A
Country	US
Kind code	B2
Filing date	Jan 24, 2017
Priority date	Mar 14, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Methods and precursors for depositing silicon nitride films by atomic layer deposition (ALD) are provided. In some embodiments the silicon precursors comprise an iodine ligand. The silicon nitride films may have a relatively uniform etch rate for both vertical and the horizontal portions when deposited onto three-dimensional structures such as FinFETS or other types of multiple gate FETs. In some embodiments, various silicon nitride films of the present disclosure have an etch rate of less than half the thermal oxide removal rate with diluted HF (0.5%).

First claim

What is claimed is:

1. A plasma enhanced atomic layer deposition (PEALD) process for depositing a silicon nitride thin film on a substrate in a reaction space comprising:
contacting the substrate with a vapor phase silicon reactant comprising iodine; and
contacting the substrate with reactive species generated by a plasma from a nitrogen precursor;
wherein a ratio of an etch rate of the silicon nitride thin film in 0.5% aqueous HF deposited on a sidewall of a three-dimensional feature to an etch rate of the silicon nitride film in 0.5% aqueous HF deposited on a top surface of the three-dimensional feature is less than about 2.

2. The process of claim 1 , wherein the contacting steps comprise a deposition cycle, the process comprising one or more deposition cycles.

3. The process of claim 2 , further comprising repeating the deposition cycle until a silicon nitride thin film of a desired thickness has been formed.

4. The process of claim 2 , wherein the deposition cycle further comprises removing excess silicon reactant and reaction byproducts, if any, after contacting the substrate with the silicon reactant and removing excess reactive species and reaction byproducts, if any, after contacting the substrate with reactive species.

5. The process of claim 1 , wherein the reactive species comprises hydrogen, hydrogen atoms, hydrogen plasma, hydrogen radicals, N*, NH* or NH 2 * radicals.

6. The process of claim 1 , wherein the nitrogen precursor is selected from the group consisting of NH 3 , N 2 H 4 , an N 2 /H 2 mixture, N 2 , and any mixtures thereof.

7. The process of claim 1 , wherein the silicon reactant comprises an organic ligand.

8. The process of claim 1 , wherein the silicon reactant comprises an iodosilane.

9. The process of claim 8 , wherein the silicon reactant comprises H 2 SiI 2 .

10. The process of claim 1 , wherein an etch rate of the silicon nitride thin film is less than 4 nm/min in 0.5% aqueous HF.

11. The process of claim 1 , wherein the silicon nitride thin film exhibits a step coverage and pattern loading effect of at least 80%.

12. The process of claim 1 , wherein the ratio is about 1.

13. A plasma enhanced atomic layer deposition (PEALD) process for forming a silicon nitride thin film on a substrate in a reaction space comprising a plurality of deposition cycles, each deposition cycle comprising:
alternately and sequentially contacting the substrate with a vapor phase silicon reactant comprising iodine and reactive species comprising nitrogen;
wherein a ratio of an etch rate of the silicon nitride thin film in 0.5% aqueous HF deposited on a vertical surface of a three-dimensional feature to an etch rate of the silicon nitride film in 0.5% aqueous HF deposited on a horizontal surface of the three-dimensional feature is less than about 2.

14. The process of claim 13 , wherein the reactive species are generated by a plasma from a nitrogen precursor.

15. The process of claim 14 , wherein the nitrogen precursor is selected from the group consisting of NH 3 , N 2 H 4 , an N 2 /H 2 mixture, N 2 , and any mixtures thereof.

16. The process of claim 13 , wherein the silicon reactant comprises an iodosilane.

17. The process of claim 13 , wherein the reactive species are generated directly above the substrate.

18. The process of claim 13 , wherein the reactive species are generated in a remote plasma generator.

19. The process of claim 13 , wherein the silicon nitride thin film is deposited during the formation a FinFET.

Assignees

• Asm Ip Holding Bv

Inventors

• Niskanen Antti J
• Chen Shang
• Pore Viljami
• Fukazawa Atsuki
• Fukuda Hideaki
• Haukka Suvi P

Classifications

• H10P50/283

  by chemical means · CPC title

• H10P14/6682

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

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10P14/69433 Primary

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