Method for forming insulation film using non-halide precursor having four or more silicons

• US 8,784,951 B2
• Filed: 11/16/2012
• Issued: 07/22/2014
• Est. Priority Date: 11/16/2012
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Fukazawa, Atsuki, Fukuka, Hideaki
• Primary Examiner(s): Matthews, Colleen
• Assistant Examiner(s): Rundio, Regan J
• Application Number:
  US13/679,502
• Publication Number:
  US 20140141625A1
• Time in Patent Office: 613 Days
• Field of Search: 427/579, 438/482
• US Class Current: 427/578
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• 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 21/0217 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• 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
• CPC Class Codes: H01L 21/32055 Deposition of semiconductive layers, e.g. poly - or amorphous silicon layers

Abstract

A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), includes: (i) adsorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space; (ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the reactant; and (iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and (iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate.

Claims

1. A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), which comprises:

(i) adsorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space, thereby producing a precursor-adsorbed substrate;

(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant, said oxygen-free reactant consisting of NH₃ or a combination of He and N₂; and

(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and

(iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate wherein the insulation film is constituted by SiN or SiCN.

2. The method according to claim 1, further comprising continuously supplying an inactive gas to the reaction space through the cycle.

3. The method according to claim 1, wherein the oxygen-free reactant is supplied continuously through the cycle.

4. The method according to claim 1, further comprising purging the reaction space between steps (i) and (ii) and between step (ill) and subsequent step (i) in the next cycle.

5. The method according to claim 1, wherein the non-excited non-halide precursor is a cyclic compound.

6. The method according to claim 5, wherein the non-excited non-halide precursor is cyclopentasilane.

7. The method according to claim 1, wherein the non-excited non-halide precursor is a non-cyclic compound.

8. The method according to claim 7, wherein the non-excited non-halide precursor is tris(trimethylsilyl)silane.

9. The method according to claim 1, wherein the non-excited non-halide precursor is oxygen-free and nitrogen-free.

10. The method according to claim 1, wherein the substrate is controlled continuously at a temperature lower than about 300°

C.

11. The method according to claim 1, wherein the substrate has patterned recesses on its surface, and the insulation film is deposited on the surface.

12. The method according to claim 11, wherein the insulation film has a sidewall coverage of about 90% or higher.

13. A method of forming an insulation film on a semiconductor substract by plasma enhanced atomic layer deposition (PEALD), which comprises:

(i) absorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in a reaction space, thereby producing a precursor-adsorbed substrate;

(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant; and

(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and

(iv) repeating steps (i) to (iii) as a cycle, thereby depositing and insulation film on the substrate,

said method further comprising purging the reaction space between steps (i) and (ii) and between step (iii) and subsequent step (i) in the next cycle, and further comprising applying RF power in a pulse immediately prior to step (ii) after step (i), and supplying another reactant while applying RF power immediately prior to step (ii) after step (i).

14. The method according to claim 13, wherein the another reactant is a rare gas.

15. A method of forming an insulation film on a semiconductor substrate by plasma enhanced atomic layer deposition (PEALD), which comprises:

(i) absorbing a non-excited non-halide precursor having four or more silicon atoms in its molecule onto a substrate placed in reaction space, thereby producing a precursor-absorbed substrate;

(ii) supplying an oxygen-free reactant to the reaction space without applying RF power so as to expose the precursor-adsorbed substrate to the oxygen-free reactant, said oxygen-free reactant consisting of He, H₂, or a mixture of He and H₂; and

(iii) after step (ii), applying RF power to the reaction space while the oxygen-free reactant is supplied in the reaction space; and

(iv) repeating steps (i) to (iii) as a cycle, thereby depositing an insulation film on the substrate,

wherein the insulation film is constituted by amorphous silicon.