Dielectric film growth with radicals produced using flexible nitrogen/hydrogen ratio

• US 8,629,067 B2
• Filed: 12/16/2010
• Issued: 01/14/2014
• Est. Priority Date: 12/30/2009
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Liang, Jingmei, Chen, Xiaolin, Miller, Matthew L., Ingle, Nitin K., Venkataraman, Shankar
• Primary Examiner(s): Swanson, Walter H
• Application Number:
  US12/969,877
• Publication Number:
  US 20110159703A1
• Time in Patent Office: 1,125 Days
• Field of Search: 438480-485, 438/513, 438/676, 438/680, 438/681, 438/771, 438/772, 438/776, 438/777, 438788-793, 257310-311, 257/374, 257/389, 257/410, 257/411, 257506-508, 257/510, 257/520, 257/524, 257632-651, 257/671, 257701-703, 257/752, 257/760, 257/E21.24
• US Class Current: 438/791
• 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 21/02274 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

Abstract

Methods of forming dielectric layers are described. The method may include the steps of mixing a silicon-containing precursor with a radical-nitrogen precursor, and depositing a dielectric layer on a substrate. The radical-nitrogen precursor is formed in a remote plasma by flowing hydrogen (H₂) and nitrogen (N₂) into the plasma in order to allow adjustment of the nitrogen/hydrogen ratio. The dielectric layer is initially a silicon-and-nitrogen-containing layer which may be converted to a silicon-and-oxygen-containing layer by curing and/or annealing the film in an oxygen-containing environment.

Claims

1. A method of forming a dielectric layer on a substrate in a plasma-free substrate processing region in a substrate processing chamber, the method comprising:

flowing precursors comprising hydrogen (H₂) and nitrogen (N₂) into a plasma region to produce a radical precursor, wherein a nitrogen;

hydrogen atomic flow ratio into the plasma region is less than 1;

3, and wherein the precursors are devoid of ammonia;

combining a vapor or gas silicon-containing precursor with the radical-nitrogen precursor in the plasma-free substrate processing region; and

depositing the dielectric layer on the substrate, wherein the dielectric layer is initially flowable as deposited.

2. The method of claim 1 wherein the vapor or gas silicon-containing precursor is a carbon-free silicon-containing precursor.

3. The method of claim 1 wherein the vapor or gas silicon-containing precursor comprises at least one of silane, disilane or trisilane.

4. The method of claim 1 wherein the nitrogen:

hydrogen atomic flow ratio is greater than or about 1;

2.

5. The method of claim 1 wherein the nitrogen:

hydrogen atomic flow ratio is less than or about 1;

5.

6. The method of claim 1 wherein the precursors are devoid of hydrazine.

7. The method of claim 1 wherein the vapor or gas silicon-containing precursor comprises a silicon-and-nitrogen-containing precursor.

8. The method of claim 1 wherein the vapor or gas silicon-containing precursor comprises a carbon-nitrogen-and-silicon-containing precursor.

9. The method of claim 1 wherein the vapor or gas silicon-containing precursor comprises at least one of H₂N(SiH₃), HN(SiH₃)₂ or N(SiH₃)₃.

10. The method of claim 1, wherein the dielectric layer comprises a carbon-free Si—

N—

H layer.

11. The method of claim 1 further comprising an operation of curing the dielectric layer by maintaining a temperature of the substrate at a curing temperature less than or about 400°

C. in an ozone-containing atmosphere.

12. 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.

13. The method of claim 12, wherein the oxygen-containing atmosphere comprises one or more gases selected from the group consisting of atomic oxygen, ozone, and steam (H₂O).

14. The method of claim 1, wherein the substrate is patterned and has a trench having a width of about 50 nm or less which is filled by the dielectric layer.

15. The method of claim 14, wherein the dielectric layer in the trench is substantially void-free.

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

17. 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.

18. A method of forming a dielectric layer on a substrate in a plasma-free substrate processing region in a substrate processing chamber, the method comprising:

flowing hydrogen (H₂) and nitrogen (N₂) into a plasma region to produce a radical precursor, wherein a nitrogen;

hydrogen atomic flow ratio into the plasma region is less than 1;

3;

combining a vapor or gas silicon-containing precursor with the radical-nitrogen precursor in the plasma-free substrate processing region;

depositing a dielectric on the substrate, wherein the dielectric is initially flowable as deposited;

increasing a flow rate of nitrogen into the plasma region to increase the nitrogen;

hydrogen atomic flow ratio;

depositing an additional dielectric on the substrate; and

curing the deposited dielectric in an oxygen environment to produce a silicon oxide film.

19. The method of claim 18, wherein during the curing operation the silicon oxide film shrinks by about 17 vol. % or less.