Method for Forming Ti-Containing Film by PEALD using TDMAT or TDEAT

• US 20150099072A1
• Filed: 10/09/2013
• Published: 04/09/2015
• Est. Priority Date: 10/09/2013
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Takamure, Noboru, Okabe, Tatsuhiro
• Granted Patent: US 9,556,516 B2
• Time in Patent Office: Days
• US Class Current: 427/577
• CPC Class Codes: C23C 16/308 Oxynitrides
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/4554 Plasma being used non-continuously in between ALD reactions C23C16/56 takes precedence
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence

Abstract

A method for forming a Ti-containing film on a substrate by plasma-enhanced atomic layer deposition (PEALD) using tetrakis(dimethylamino)titanium (TDMAT) or tetrakis(diethylamino)titanium (TDEAT), includes: introducing TDMAT and/or TDEAT in a pulse to a reaction space where a substrate is placed; continuously introducing a NH₃-free reactant gas to the reaction space; applying RF power in a pulse to the reaction space wherein the pulse of TDMAT and/or TDEAT and the pulse of RF power do not overlap; and repeating the above steps to deposit a Ti-containing film on the substrate.

Claims

1. A method for forming a Ti-containing film on a substrate by plasma-enhanced atomic layer deposition (PEALD) using tetrakis(dimethylamino)titanium (TDMAT) or tetrakis(diethylamino)titanium (TDEAT), comprising:

(i) introducing TDMAT and/or TDEAT in a pulse to a reaction space where a substrate is placed;

(ii) continuously introducing a NH₃-free reactant gas to the reaction space;

(iii) applying RF power in a pulse to the reaction space wherein the pulse of TDMAT and/or TDEAT and the pulse of RF power do not overlap; and

(iv) repeating steps (i) to (iii) to deposit a Ti-containing film on the substrate.

2. The method according to claim 1, wherein the NH₃-free reactant gas is H₂ and/or N₂.

3. The method according to claim 1, wherein the NH₃-free reactant gas contains no nitrogen or no oxygen.

4. The method according to claim 1, wherein the NH₃-free reactant gas comprises oxygen.

5. The method according to claim 2, wherein the NH₃-free reactant gas consists of H₂ and a rare gas, thereby depositing a TiN crystalline film as the Ti-containing film in step (iv).

6. The method according to claim 2, wherein the NH₃-free reactant gas consists of H₂, N₂, and a rare gas, thereby depositing a TiCN amorphous film as the Ti-containing film in step (iv).

7. The method according to claim 1, wherein the Ti-containing film has a film stress of −

2,500 MPa to 800 MPa.

8. The method according to claim 1, further comprising:

setting a target film stress for the Ti-containing film, which is greater than a film stress of a TiN crystalline film being deposited by steps (i) to (iv) under deposition conditions including a reference flow rate of H₂ used as the reactant gas in step (ii), reference RF power used in step (iii), and a reference deposition temperature throughout steps (i) to (iii); and

setting a flow rate of H₂ used as the reactant gas in step (ii), RF power used in step (iii), and a deposition temperature throughout steps (i) to (iii), wherein only one or more of the flow rate of H₂, the RF power, and the deposition temperature are used as control parameters for changing the film stress, and are different from the reference flow rate of H₂, the reference RF power, and the reference deposition temperature, followed by conducting steps (i) to (iv) for depositing the Ti-containing film.

9. The method according to claim 8, wherein the Ti-containing film has tensile film stress.

10. The method according to claim 9, wherein the set flow rate of H₂ is lower than the reference flow rate of H₂ used for the TiN crystalline film.

11. The method according to claim 9, wherein the set RF power is lower than the reference RF power used for the TiN crystalline film.

12. The method according to claim 9, wherein the set deposition temperature is higher than the reference deposition temperature used for the TiN crystalline film.

13. The method according to claim 9, wherein the Ti-containing film contains about 4% to about 9% carbon.

14. The method according to claim 9, wherein the Ti-containing film shows a peak at 2,000 cm⁻

1 and substantially no peak at 1,400 cm<sup>−

1</sup> in a Fourier Transform Infrared Spectroscopy (FT-IR) graph.

15. The method according to claim 1, wherein the NH₃-free reactant gas is comprised of a reactant gas containing no oxygen and a reactant gas containing oxygen, and in step (iv), when steps (i) to (iii) are repeated, the NH₃-free oxygen-free reactant gas and the NH₃-free oxygen-containing gas are alternately used at set intervals.

16. The method according to claim 15, wherein the NH₃-free oxygen-free reactant gas is hydrogen gas without nitrogen gas, and the NH₃-free oxygen-containing gas is oxygen gas, thereby forming a TiON film consisting of TiO films and TiN films deposited alternately at set intervals.

17. The method according to claim 15, wherein the NH₃-free oxygen-free reactant gas is hydrogen gas and nitrogen gas, and the NH₃-free oxygen-containing gas is oxygen gas thereby forming a TiOCN film consisting of TiO films and TiCN films deposited alternately at set intervals.

18. The method according to claim 1, further comprising annealing the Ti-containing film on the substrate in an atmosphere of oxygen after step (iv) so as to form a TiO film having an anatase crystal as the Ti-containing film in step (iv).