Method for forming insulation film having high density

• US 20080076266A1
• Filed: 09/21/2006
• Published: 03/27/2008
• Est. Priority Date: 09/21/2006
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Matsuki, Nobuo, Fukazawa, Atsuki
• Granted Patent: US 7,718,553 B2
• Time in Patent Office: Days
• US Class Current: 438/780
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/3144 on silicon
• CPC Class Codes: H01L 21/3145 formed by deposition from a gas or vapour
• CPC Class Codes: H01L 21/31612 on a silicon body

Abstract

A method for forming an insulation film on a semiconductor substrate by plasma reaction includes: introducing into a reaction chamber a source gas of a silicon-containing hydrocarbon compound comprising in its molecule at least one Si—O bond and at least one bond selected from the group consisting of a Si—Si bond, Si—N bond, and Si—H bond; introducing into the reaction chamber an additive gas constituted by C, H, and optionally O; controlling a susceptor at a temperature of −50° C. to 50° C.; forming by plasma reaction an insulation film constituted by Si, O, H, and optionally N on an irregular surface of a substrate at a deposition rate of 100 nm/min or less; and heat-treating the substrate with the insulation film, thereby increasing a density of the insulation film to more than 2.1 g/cm³ as a result of the heat treatment.

Claims

1. A method for forming an insulation film on a semiconductor substrate by plasma reaction, comprising the steps of:

providing a substrate having an irregular surface including concave portions placed on a susceptor in a reaction chamber;

introducing into the reaction chamber a process gas comprising;

(i) a source gas of a silicon-containing hydrocarbon compound comprising in its molecule at least one Si—

O bond and at least one bond selected from the group consisting of a Si—

Si bond, Si—

N bond, and Si—

H bond; and

(ii) an additive gas constituted by C, H, and optionally O;

controlling the susceptor at a temperature of −

50°

C. to 50°

C.; and

depositing by plasma reaction an insulation film constituted by Si, O, H, and optionally N on the irregular surface of the substrate including the concave portions at a deposition rate of 100 nm/min or less.

2. The method according to claim 1, further comprising heat-treating the substrate with the insulation film, thereby increasing a density of the insulation film to more than 2.12 g/cm³ as a result of the heat treatment.

3. The method according to claim 1, further comprising, as a preliminary treatment, introducing an auxiliary gas selected from the group consisting of oxidizing gas, inert gas, and a gas constituted by C, H, and optionally O into the reaction chamber for plasma treatment of the substrate before introducing the reaction gas.

4. The method according to claim 1, wherein the process gas further comprises an oxidizing gas and an inert gas.

5. The method according to claim 4, wherein a flow rate of the source gas is no more than 2.8% of the total flow rate of the process gas.

6. The method according to claim 1, wherein the additive gas is isopropyl alcohol or acetone.

7. The method according to claim 1, wherein the irregular surface has a three-dimensional structure of aluminum, tungsten, or tungsten silicon.

8. The method according to claim 1, wherein the insulation film has a thickness of 25 nm to 70 nm.

9. The method according to claim 1, wherein the irregular surface with the concave portion is a patterned surface for wiring.

10. The method according to claim 1, wherein the concave portion of the irregular surface of the substrate has an aspect ratio of about 1/3 to about 1/10.

11. The method according to claim 3, wherein the auxiliary gas is He or H₂.

12. The method according to claim 3, wherein the auxiliary gas is isopropyl alcohol, acetone, or hexane.

13. The method according to claim 2, wherein the heat-treating step is performed by thermal annealing or UV curing.

14. The method according to claim 13, wherein the annealing step is performed at a temperature of 200°

C. to 1,100°

C.

15. The method according to claim 1, wherein the concave portion of the irregular surface has holes or grooves, and the deposition step is performed on the irregular surface to fill the holes or grooves with the insulation film.

16. The method according to claim 1, wherein the insulation film is a silicon oxide film.

17. The method according to claim 1, wherein said silicon-containing hydrocarbon compound is at least one compound selected from the group consisting of:

wherein each X is independently H, OH, CH₃, C₂H₅, OCH₃, or OC₂H₅, and Y is H, CH₃, or C₂H₅.

18. The method according to claim 16, wherein at least one X is neither H nor OH in each formula.

19. A method for forming an interconnect structure, comprising the steps of:

forming a three-dimensional structure for interconnect in a substrate; and

forming an insulation layer on a surface of the three-dimensional structure using the method of claim 1.

20. The method according to claim 19, further comprising wet-etching the insulation film.

21. The method according to claim 19, wherein the step of forming a three-dimensional structure comprises forming a layer of aluminum, tungsten, or tungsten silicon as a wiring layer and etching the layer in a pattern.