Method for forming silazane-based dielectric film

• US 7,651,959 B2
• Filed: 12/03/2007
• Issued: 01/26/2010
• Est. Priority Date: 12/03/2007
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Ha, Jeongseok, Matsuki, Nobuo, Fukazawa, Atsuki
• Primary Examiner(s): Garber; Charles D
• Assistant Examiner(s): Abdelaziez; Yasser A
• Application Number:
  US11/949,701
• Publication Number:
  US 20090142935A1
• Time in Patent Office: 785 Days
• Field of Search: 438792-794, 438/782, 438/769, 257/77, 257/639, 257/649, 257/E21.267, 427/255.29
• US Class Current: 438/786
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/45512 Premixing before introduction in the reaction chamber
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• 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 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02315 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/3125 layers comprising silazane compounds
• CPC Class Codes: H01L 21/3185 of siliconnitrides

Abstract

A method of forming a dielectric film includes: introducing a source gas essentially constituted by Si, N, H, and optionally C and having at least one bond selected from Si—N, Si—Si, and Si—H into a reaction chamber where a substrate is placed; depositing a silazane-based film essentially constituted by Si, N, H, and optionally C on the substrate by plasma reaction at −50° C. to 50° C., wherein the film is free of exposure of a solvent constituted essentially by C, H, and optionally O; and heat-treating the silazane-based film on the substrate in a heat-treating chamber while introducing an oxygen-supplying source into the heat-treating chamber to release C from the film and increase Si—O bonds in the film.

Claims

1. A method of forming a dielectric film, comprising:

introducing a source gas comprising Si, N, H, and optionally C and having at least one bond selected from Si—

N, Si—

Si, and Si—

H into a reaction chamber where a substrate is placed;

depositing a silazane-based film comprising Si, N, H, and optionally C on the substrate in a liquid or flowable state by plasma reaction at −

50°

C. to 50°

C., wherein the film is free of exposure of a solvent comprising C, H, and optionally O;

heat-treating the silazane-based film on the substrate in a heat-treating chamber while introducing an oxygen-supplying source into the heat-treating chamber to release C from the film and increase Si—

O bonds in the film; and

high heat-treating the film at a temperature of 700°

C.-1,000°

C. in an inert gas environment upon the heat treatment step.

2. The method according to claim 1, wherein the heat-treatment step comprises introducing O₂, O₃, CO₂, N₂O, and/or H₂O as the oxygen-supplying source and an inert gas into the heat-treating chamber and annealing the film by UV curing.

3. The method according to claim 1, wherein the substrate is placed between capacitively-coupled electrodes, between which a plasma is generated in the deposition step, and a gap between the electrodes is set at 16 mm or less in the deposition step.

4. The method according to claim 1, wherein the substrate is placed between capacitively-coupled electrodes, between which a plasma is generated in the deposition step, and the source gas is a mixture of a gas comprising Si, H, and N and a gas comprising Si, H, N, and C.

5. The method according to claim 1, wherein the source gas is a mixture of a gas constituted by Si, H, and optionally C, and a gas constituted by N and optionally H.

6. The method according to claim 5, wherein the gas constituted by N and optionally H is NH₃ or/and N₂.

7. The method according to claim 1, wherein the heat-treatment step comprises introducing H₂O as the oxygen-supplying source into the heat-treating chamber and annealing the film at a temperature of 85°

C.-150°

C.

8. The method according to claim 1, wherein the heat-treatment step comprises introducing O₂, O₃, CO₂, N₂O, and/or H₂O as the oxygen-supplying source and an inert gas into the heat-treating chamber and annealing the film at a temperature of 200°

C.-600°

C.

9. A method of forming a dielectric film, comprising:

introducing a source gas comprising Si, N, H, and optionally C and having at least one bond selected from Si—

N, Si—

Si, and Si—

H into a reaction chamber where a substrate is placed; and

depositing a silazane-based film comprising Si, N, H, and optionally C on the substrate in a liquid or flowable state by plasma reaction at −

50°

C. to 50°

C., wherein the film is free of exposure of a solvent comprising C, H, and optionally O,

wherein the substrate is placed between capacitively-coupled electrodes, between which a plasma is generated in the deposition step,

the source gas comprises Si, H, N, and C, and a gap between the electrodes is set at 16 mm or more in the deposition step, and

no hydrocarbon gas is introduced into the reaction chamber.

10. The method according to claim 9, wherein RF power applied to the electrodes is 600 W or less in the deposition step.

11. The method according to claim 9, wherein the substrate is a semiconductor substrate which has an irregular surface including a concave portion.

12. The method according to claim 11, wherein the concave portion is filled with the film by conducting the gas-introducing step and the deposition step once or by repeating the gas-introducing step and the deposition step multiple times, and then the heating-treatment step is conducted.

13. The method according to claim 11, 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 inorganic silazane-based film.

14. The method according to claim 9, wherein the substrate has a silicon oxide conformal film formed from a siloxane material, on which the silazane-based film is deposited in the deposition step.

15. The method according to claim 9, wherein the silazane-based film is comprised of multiple silazane-based films which are constituted by Si, N, and H, and/or constituted by Si, N, H, and C.

16. The method according to claim 9, wherein in the gas-introducing step, an inert gas is added.

17. The method according to claim 9, further comprising treating a surface of the substrate with a plasma using He, Ar, or N₂ for improving affinity to the silazane-based film prior to the gas-introducing step.

18. The method according to claim 9, wherein in the gas-introducing step, no oxygen-supplying gas is introduced into the reaction chamber.

19. The method according to claim 9, further comprising cleaning the reaction chamber at a temperature of higher than 50°

C. after the film depositing step is repeated multiple times.

20. The method according to claim 9, further comprising heat-treating the silazane-based film on the substrate in a heat-treating chamber while introducing N₂ into the heat-treating chamber and annealing the film by UV curing.

21. A method for forming an interconnect structure, comprising:

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 9, followed by

heat-treating the silazane-based film on the substrate in a heat-treating chamber while introducing an oxygen-supplying source into the heat-treating chamber to release C from the film and increase Si—

O bonds in the film.

22. The method according to claim 21, further comprising wet-etching the insulation film.

23. The method according to claim 21, 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.

24. A method of forming a dielectric film, comprising:

introducing a source gas comprising Si, N, H, and optionally C and having at least one bond selected from Si—

N, Si—

Si, and Si—

H into a reaction chamber where a substrate is placed; and

depositing a silazane-based film comprising Si, N, H, and optionally C on the substrate in a liquid or flowable state by plasma reaction at −

50°

C. to 50°

C., wherein the film is free of exposure of a solvent comprising C, H, and optionally O,

wherein the substrate is placed between capacitively-coupled electrodes, between which a plasma is generated in the deposition step,

the source gas comprises Si, H, N, and C, and a gap between the electrodes is set at 16 mm or more in the deposition step, and

the source gas is comprised of a gas constituted by Si, N, H, and C, and a gas constituted by N and optionally H.

25. The method according to claim 24, wherein the source gas is further comprised of a gas constituted by Si and H.