Post-deposition treatment to enhance properties of Si-O-C low K films

• US 6,486,061 B1
• Filed: 08/07/2000
• Issued: 11/26/2002
• Est. Priority Date: 08/17/1999
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Xia, Li-Qun, Gaillard, Frederic, Yieh, Ellie, Lim, Tian H.
• Primary Examiner(s): Nguyen, Viet Q.
• Assistant Examiner(s): Nhu, David
• Application Number:
  US09/632,669
• Time in Patent Office: 841 Days
• Field of Search: 438/502, 438/503, 438/507, 438/509, 438/513, 438/680, 438/780, 438/781, 438/784, 438/789, 438/788, 438/909, 438/931, 438/935
• US Class Current: 438/680
• CPC Class Codes: C23C 16/0218 in a reactive atmosphere C23C16/0227 takes precedence
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02071 the processing being a delineation, e.g. RIE, of conductive layers
• 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 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02312 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/3146 Carbon layers, e.g. diamond-like layers
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/31633 Deposition of carbon doped silicon oxide, e.g. SiOC
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76826 : by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76837 : Filling up the space between adjacent conductive structures; Gap-filling properties of dielectrics
• CPC Class Codes: Y10S 438/931 : Silicon carbide semiconductor

Abstract

A method for providing a dielectric film having enhanced adhesion and stability. The method includes a post deposition treatment that densifies the film in a reducing atmosphere to enhance stability if the film is to be cured ex-situ. The densification generally takes place in a reducing environment while heating the substrate. The densification treatment is particularly suitable for silicon-oxygen-carbon low dielectric constant films that have been deposited at low temperature.

Claims

1. A method for forming an insulation layer over a substrate and treating the insulation layer after its formation, the method comprising:

flowing a process gas into a substrate processing chamber in which the substrate is disposed;

heating the substrate in the substrate processing chamber to form a carbon-doped silicon oxide insulation layer over the substrate with said process gas;

densifying the insulation layer by exposing the substrate to a reducing environment; and

thereafter, curing the insulation layer.

2. The method of claim 1 wherein said densifying includes heating the substrate.

3. The method of claim 2 wherein said reducing environment comprises one of ammonia (NH₃) and hydrogen (H₂).

4. The method of claim 2 wherein said reducing atmosphere comprises ammonia (NH₃) at a pressure of between 200 and 700 torr during said densification.

5. The method of claim 4 wherein the substrate is heated to a temperature of between 300 and 500°

C. during said densification.

6. The method of claim 5 wherein the substrate is heated for between 1 and 5 minutes during said densification.

7. Then method of claim 1, wherein the curing is done ex-situ in a furnace.

8. The method of claim 7 wherein said curing heats the substrate to a temperature between 300 and 500°

C. for at least 15 minutes.

9. The method of claim 1, wherein said process gas includes an organosilane precursor having at least one silicon-carbon bond.

10. The method of claim 9 wherein the organosilane precursor is selected from the group consisting of methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane and phenylmethylsilane.

11. The method of claim 9 wherein said process gas further includes ozone.

12. The method of claim 1 wherein said substrate is heated to a temperature of less than about 250°

C.

13. A method of forming a carbon-doped silicon oxide layer over a substrate, the method comprising:

depositing the carbon-doped silicon oxide layer over the substrate from a process gas that includes an organosilane precursor having at least one silicon-carbon bond and ozone while heating the substrate to a temperature less than 250°

C.;

thereafter, heating the carbon-doped silicon oxide layer in a reducing environment; and

thereafter, curing the carbon-doped silicon layer by heating the layer to a temperature between 300-500°

C. for at least 15 minutes.