Method of forming insulation film by modified PEALD

• US 10,378,106 B2
• Filed: 11/13/2009
• Issued: 08/13/2019
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Kobayashi, Akiko, Shimizu, Akira, Kobayashi, Nobuyoshi, Lee, Woo-Jin
• Primary Examiner(s): Wieczorek, Michael P
• Assistant Examiner(s): Miller, Michael G
• Application Number:
  US12/618,355
• Publication Number:
  US 20100124621A1
• Time in Patent Office: 3,560 Days
• Field of Search: 4272481-2557
• CPC Class Codes: C23C 16/325 Silicon carbide
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD

Abstract

A method of forming an insulation film by alternating multiple times, respectively, a process of adsorbing a precursor onto a substrate and a process of treating the adsorbed surface using reactant gas and a plasma, wherein a plasma is applied in the process of supplying the precursor.

Claims

1. A method of forming an insulation film by plasma enhanced atomic layer deposition (PEALD), comprising in the following sequence:

(i) introducing a precursor without a reactant gas into a reaction space where a substrate is placed, which precursor is an aminosilane compound;

(ii) exciting the precursor in the reaction space with a plasma by applying a first RF power to the reaction space for adsorbing the precursor on a surface of the substrate;

(iii) adsorbing the plasma-treated precursor onto the surface of the substrate;

(iiia) purging the reaction space between steps (iii) and (iv) without RF power;

(iv) introducing a reactant gas without a precursor to the reaction space and exciting the reactant gas with a plasma by applying a second RF power to the reaction space to treat the precursor-adsorbed surface with the excited reactant gas to form and fix a film on the surface, wherein the reactant gas is NO₂, O₂, H₂, CO₂, N₂O, N₂ and/or NH₃,

wherein steps (i) to (iv) constitute one cycle of PEALD, wherein the first RF power is lower than the second RF power wherein the first RF power is less than 50 W so as to maintain a step coverage of the film at 90% or higher as measured for an aspect ratio (depth/opening width) of 3, and the second RF power is 100 W or more; and

(v) repeating the one cycle multiple times until an atomic layer of a desired thickness is obtained.

2. The method according to claim 1, wherein no reactant gas is supplied in steps (i) to (iii).

3. The method according to claim 1, wherein the insulation film is constituted by a silicon compound.

4. The method according to claim 3, wherein the silicon compound is SiO, SiN, SiC, SiON, SiCON, SiCO, SiBN, SiBO or SiCN.

5. The method according to claim 1, wherein the first RF power is less than 1/10 of the second RF power.

6. The method according to claim 1, wherein the first RF power is less than 0.07 W/cm² per area of the substrate.

7. The method according to claim 1, wherein the process pressures in steps (i) to (iv) are in a range of 50 to 2000 Pa.

8. The method according to claim 1, wherein the plasmas in steps (ii) and (iv) are generated in a gap between capacitively-coupled parallel plate electrodes.

9. The method according to claim 1, wherein in the one cycle, a duration of step (ii) is 0.2 to 5 seconds, a duration of step (iv) is 0.2 to 5 seconds, and an interval between step (ii) and step (iv) is 0 to 5 seconds.

10. The method according to claim 1, wherein the surface has a trench, and the method further comprises, prior to step (i), setting a target step coverage of the insulation film at the trench, and setting the first value of RF power according to the target step coverage based on a predetermined correlation between a value of RF power and step coverage for the insulation film.