Low cost flowable dielectric films

• US 8,889,566 B2
• Filed: 11/05/2012
• Issued: 11/18/2014
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chatterjee, Amit, Mallick, Abhijit Basu, Ingle, Nitin K., Underwood, Brian, Thadani, Kiran V., Chen, Xiaolin, Dube, Abhishek, Liang, Jingmei
• Primary Examiner(s): WILCZEWSKI, MARY A
• Application Number:
  US13/668,657
• Publication Number:
  US 20140073144A1
• Time in Patent Office: 743 Days
• Field of Search: 438/793, 438/778, 427/249.15, 427/255.18, 427/255.17, 427/255.393, 427/255.394
• US Class Current: 438/778
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• 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 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]

Abstract

A method of forming a dielectric layer is described. The method deposits a silicon-containing film by chemical vapor deposition using a local plasma. The silicon-containing film is flowable during deposition at low substrate temperature. A silicon precursor (e.g. a silylamine, higher order silane or halogenated silane) is delivered to the substrate processing region and excited in a local plasma. A second plasma vapor or gas is combined with the silicon precursor in the substrate processing region and may include ammonia, nitrogen (N₂), argon, hydrogen (H₂) and/or oxygen (O₂). The equipment configurations disclosed herein in combination with these vapor/gas combinations have been found to result in flowable deposition at substrate temperatures below or about 200° C. when a local plasma is excited using relatively low power.

Claims

1. A method of forming a dielectric layer on a patterned substrate, the method comprising:

Transferring the patterned substrate into a substrate processing region;

flowing a silicon precursor into the substrate processing region;

flowing a plasma vapor/gas into the substrate processing region, wherein flowing the plasma vapor/gas and flowing the silicon precursor occur concurrently;

striking a plasma in the substrate processing region by applying a plasma power less than or about 0.3 W per square centimeter of patterned substrate area; and

forming the dielectric layer on the patterned substrate, wherein the dielectric layer comprises silicon and one of nitrogen or carbon and the dielectric layer is flowable during deposition,

wherein flowing the silicon precursor comprises supplying a continuous flow of the silicon precursor to the substrate processing region throughout formation of the flowable dielectric layer, and wherein striking a plasma comprises applying a plasma power continuously throughout formation of the flowable dielectric layer.

2. The method of claim 1 wherein a temperature of the patterned substrate is less than 200°

C. while forming the flowable dielectric layer.

3. The method of claim 1 wherein the plasma vapor/gas comprises one of ammonia, hydrogen (H₂), argon, nitrogen (N₂), a hydrocarbon or oxygen (O₂).

4. The method of claim 1 wherein the silicon precursor is one of trisilylamine, disilylamine or monosilylamine.

5. The method of claim 1 wherein the silicon precursor comprises a higher order silane containing three or more silicon atoms.

6. The method of claim 1 wherein the silicon precursor comprises a halogen-substituted silane.

7. The method of claim 6 wherein the halogen-substituted silane is hexachlorodisilane.

8. The method of claim 1 wherein the dielectric layer is one of silicon carbide, silicon nitride or SiCN.

9. The method of claim 1 wherein the dielectric layer consists of silicon, nitrogen, and hydrogen.

10. The method of claim 1 wherein the dielectric layer consists of silicon, carbon, nitrogen, and hydrogen.

11. The method of claim 1 wherein striking the plasma comprises applying radio frequencies (RF) to the substrate processing region by either capacitive or inductive means.

12. The method of claim 1 wherein striking the plasma comprises shining ultraviolet (UV) light into the substrate processing region.

13. The method of claim 1 wherein striking the plasma comprises applying 0.025 W to 0.30 W (per square centimeter of patterned surface area) of plasma power to the substrate processing region.

14. The method of claim 1 wherein striking the plasma comprises applying plasma power continuously throughout while forming the dielectric layer.

15. The method of claim 1 wherein the substrate is patterned and has a trench having a width of about 50 nm or less.

16. The method of claim 1 further comprising solidifying the dielectric layer after the operation of forming the dielectric layer.

17. The method of claim 16 wherein a thickness of the dielectric layer after solidification is about 25 nm or less perpendicular to the major plane of the patterned substrate.

18. The method of claim 1 wherein the silicon precursor, the plasma vapor/gas and the dielectric layer are each carbon-free.

19. The method of claim 1 wherein a temperature of the patterned substrate is less than 100°

C. while forming the flowable dielectric layer.

20. The method of claim 1 wherein a temperature of the patterned substrate is less than 30°

C. while forming the flowable dielectric layer.