In-situ ozone cure for radical-component CVD

• US 8,304,351 B2
• Filed: 12/20/2010
• Issued: 11/06/2012
• Est. Priority Date: 01/07/2010
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wang, Linlin, Mallick, Abhijit Basu, Ingle, Nitin K., Venkataraman, Shankar
• Primary Examiner(s): Coleman, William D
• Assistant Examiner(s): Enad, Christine
• Application Number:
  US12/972,711
• Publication Number:
  US 20120003840A1
• Time in Patent Office: 687 Days
• Field of Search: 438/761, 438/762, 438/775, 438/778, 438/784, 438/786, 438/787, 438/798, 427/255.18, 427/255.27, 257/E21.241
• US Class Current: 438/761
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• 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 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02326 into a nitride layer, e.g. changing SiN to SiON
• 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

Abstract

Methods of forming a dielectric layer are described. The methods include the steps of mixing a silicon-containing precursor with a plasma effluent, and depositing a silicon-and-nitrogen-containing layer on a substrate. The silicon-and-nitrogen-containing layer is converted to a silicon-and-oxygen-containing layer by curing in an ozone-containing atmosphere in the same substrate processing region used for depositing the silicon-and-nitrogen-containing layer. Another silicon-and-nitrogen-containing layer may be deposited on the silicon-and-oxygen-containing layer and the stack of layers may again be cured in ozone all without removing the substrate from the substrate processing region. After an integral multiple of dep-cure cycles, the conversion of the stack of silicon-and-oxygen-containing layers may be annealed at a higher temperature in an oxygen-containing environment.

Claims

1. A method of forming a silicon-and-oxygen-containing layer on a substrate in a substrate processing region in a substrate processing chamber, the method comprising:

forming a silicon-and-nitrogen-containing layer on the substrate in the substrate processing region, wherein forming the silicon-and-nitrogen-containing layer comprises;

flowing a stable gas into a plasma region to produce plasma effluents,

combining a silicon-containing precursor with the plasma effluents in the plasma-free substrate processing region, wherein the silicon-containing precursor is carbon-free, and

depositing a silicon-and-nitrogen-containing layer on the substrate; and

curing the silicon-and-nitrogen-containing layer in an ozone-containing atmosphere in the same substrate processing region in the substrate processing chamber to form the silicon-and- oxygen-containing layer, wherein a substrate temperature during the curing operation is less than 50°

C. higher than a substrate temperature during the operation of depositing the silicon-and-nitrogen-containing layer.

2. The method of claim 1 further comprising forming a second silicon-and-nitrogen-containing layer on the substrate in the substrate processing region, wherein forming the second silicon-and-nitrogen-containing layer comprises:

flowing the stable gas into the plasma region to produce plasma effluents,

combining a silicon-containing precursor with the plasma effluents in the substrate processing region, and

depositing the second silicon-and-nitrogen-containing layer on the substrate in the substrate processing region; and

curing the second silicon-and-nitrogen-containing layer in an ozone-containing atmosphere in the substrate processing region.

3. The method of claim 1 wherein the substrate processing region is plasma-free during the operation of forming the silicon-and-nitrogen-containing layer to avoid direct plasma-excitation of the silicon-containing precursor.

4. The method of claim 1 wherein the substrate processing region is plasma-free during the operation of curing the silicon-and-nitrogen-containing layer.

5. The method of claim 1 wherein a substrate temperature during the operation of depositing the silicon-and-nitrogen-containing layer is less than 100°

C.

6. The method of claim 1 wherein a substrate temperature during the curing operation is less than 200°

C.

7. The method of claim 1 wherein a thickness of the silicon-and-nitrogen-containing layer is less than or about 1500Å

.

8. The method of claim 1 wherein the substrate is raised towards a heated showerhead to heat the substrate during the curing operation.

9. The method of claim 1 wherein the stable gas is a nitrogen-and-hydrogen-containing gas and the plasma effluents comprise a radical-nitrogen precursor.

10. The method of claim 9 wherein the nitrogen-and-hydrogen-containing gas comprises ammonia.

11. The method of claim 1 wherein the silicon-containing precursor comprises a silicon-and-nitrogen-containing precursor.

12. The method of claim 1 wherein the silicon-containing precursor comprises N(SiH₃)₃.

13. The method of claim 1 wherein the silicon-and-nitrogen-containing layer comprises a carbon-free Si—

N—

H layer.

14. The method of claim 1 further comprising raising a temperature of the substrate to an oxygen anneal temperature above or about 600°

C. in an oxygen-containing atmosphere after the curing operation.

15. The method of claim 14 wherein the oxygen-containing atmosphere comprises one or more gases selected from the group consisting of atomic oxygen, ozone, and steam (H₂O).

16. The method of claim 1 wherein the substrate is patterned and has a trench having a width of about 45 nm or less, and wherein the silicon oxide layer formed in the trench is substantially void-free.

17. The method of claim 1 wherein the plasma region is in a remote plasma system.

18. The method of claim 1 wherein the plasma region is a partitioned portion of the substrate processing chamber separated from the plasma-free substrate processing region by a showerhead.