METHOD FOR FORMING SILICON CARBIDE FILM CONTAINING OXYGEN

• US 20080038485A1
• Filed: 08/08/2006
• Published: 02/14/2008
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: KATO, Manabu, MATSUKI, Nobuo, FUKAZAWA, Atsuki
• Granted Patent: US 8,080,282 B2
• Time in Patent Office: Days
• US Class Current: 427/585
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/325 Silicon carbide

Abstract

A method for forming a silicon carbide film containing Si, C, O, H, and optionally N on a substrate placed in a reaction space, includes the steps of: introducing into the reaction space a precursor containing Si, C, O, and H and having at least one Si—O bond in its molecule; introducing into the reaction space an inert gas; applying RF power in the reaction space, wherein a ratio of a flow rate (sccm) of the inert gas to the RF power (W/cm²) is controlled at 30-850; and thereby depositing on the substrate a silicon carbide film containing Si, C, O, H, and optionally N.

Claims

1. A method for forming a silicon carbide film containing Si, C, O, H, and optionally N on a substrate placed in a reaction space, comprising the steps of:

introducing into the reaction space a precursor containing Si, C, O, and H and having at least one Si—

O bond in its molecule;

introducing into the reaction space an inert gas;

applying RF power in the reaction space, wherein a ratio of a flow rate (sccm) of the inert gas to the RF power (W/cm²) is controlled at more than zero but no more than 850; and

thereby depositing on the substrate a silicon carbide film containing Si, C, O, H, and optionally N.

2. The method according to claim 1, wherein the ratio of the flow rate of the inert gas to the RF power is controlled to adjust a dielectric constant (k) and a density (ρ

, g/cm³) of the depositing silicon carbide film to satisfy the following equation;

1.6·

ρ

≦

k≦

1.6·

ρ

+1.0.

3. The method according to claim 1, wherein in the reaction space, the RF power is applied at 0.3-7 W/cm², and the inert gas is introduced at a flow rate of 20-1,100 sccm.

4. The method according to claim 1, wherein the ratio of the flow rate (sccm) of the inert gas to the RF power (W/cm²) is controlled at 30-550.

5. The method according to claim 1, wherein no oxidizing gas is added to the precursor.

6. The method according to claim 1, wherein the precursor and the inert gas are exclusively introduced into the reaction space.

7. The method according to claim 1, wherein the depositing silicon carbide film has a dielectric constant of 2.8-3.8.

8. The method according to claim 1, wherein the depositing silicon carbide film has a density of 1.4-2.0 g/cm³.

9. The method according to claim 1, further comprising forming a copper layer prior to the step of forming the silicon carbide film, wherein the silicon carbide film is formed on top of the copper layer as a barrier layer.

10. The method according to claim 1, further comprising forming a layer-to-be-etched by photolithography prior to the step of forming the silicon carbide film, wherein the silicon carbide film is formed on the layer-to-be-etched as an antireflection layer.

11. The method according to claim 10, wherein the antireflection layer has an n value of 1.4 to 2.0 and a k value of 0.10 to 0.45 at 193 nm.

12. The method according to claim 1, wherein the silicon carbide film is deposited at a thickness of 10-50 nm.

13. The method according to claim 1, wherein the precursor gas is an organosilicon gas having a general formula Si_aO_bC_xH_y wherein, a, b, x, and y are arbitrary integers.

14. The method according to claim 13, wherein the organosilicon gas is at least one member selected from the group consisting of:

wherein R¹, R², R³ and R⁴ are independently any one of CH₃, C₂H₅, C₃H₇, C₆H₅, C₂H₃, C₃H₅, C₄H₇ and C₄H₅,

wherein R¹, R², R³ and R⁴ are independently any one of CH₃, C₂H₅, C₃H₇, C₆H₅, C₂H₃, C₃H₅, C₄H₇ and C₄H₅;

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are independently any one of CH₃, C₂H₅, C₃H₇, C₆H₅, C₂H₃, C₃H₅, C₄H₇ and C₄H₅;

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are independently any one of CH₃, C₂H₅, C₃H₇, C₆H₅, C₂H₃, C₃H₅, C₄H₇ and C₄H₅;

15. The method according to claim 1, wherein the inert gas is selected from the group consisting of He, Ar, Kr, and Xe.

16. The method according to claim 1, wherein the RF power has a high frequency and a low frequency, said high frequency being 13.56 MHz, 27 MHz, or 60 MHz, said low frequency being 5 MHz or lower.

17. The method according to claim 1, wherein the inert gas is nitrogen gas to incorporate N in the silicon carbide film which contains Si, C, O, H, and N.

18. A method for forming a silicon carbide film containing Si, C, O, H, and optionally N on a substrate placed in a reaction space, comprising:

a step of introducing into the reaction space a precursor containing Si, C, O, and H and having at least one Si—

O bond in its molecule and an inert gas;

a step of applying RF power in the reaction space; and

a step for depositing on the substrate a silicon carbide film containing Si, C, O, H, and optionally N, while adjusting a dielectric constant (k) and a density (ρ

, g/cm³) of the depositing silicon carbide film to satisfy the following equation;

1.6·

ρ

≦

k≦

1.6·

ρ

+1.0.

19. The method according to claim 18, wherein the step for depositing the silicon carbide film comprises controlling a ratio of a flow rate (sccm) of the inert gas to the RF power (W/cm²) at 30-850.

20. The method according to claim 18, wherein the step of introducing the precursor and the inert gas uses no gas other than the precursor gas and the inert gas.

21. A silicon carbide film having a dielectric constant (k) and a density (ρ

, g/cm³) which satisfy the following equation;

1.6·

ρ

≦

k≦

1.6·

ρ

+1.0.

22. The silicon carbide film according to claim 21, which has a dielectric constant of 2.8-3.8.

23. The silicon carbide film according to claim 21, which has a density of 1.4-2.0 g/cm³.

24. The silicon carbide film according to claim 21, which has a copper penetration depth of 20 nm or less as measured when the silicon carbide film is deposited on a copper layer and kept at 400°

C. for four hours.

25. The silicon carbide film according to claim 21, which has a moisture penetration inhibition property.

26. The silicon carbide film according to claim 21, which has a refractive index (n) of 1.4 to 2.0 and an extinction coefficient (k) of 0.10 to 0.45 at 193 nm.

27. The silicon carbide film according to claim 26, which contains no nitrogen.