Silicon pretreatment for nitride removal

• US 10,128,086 B1
• Filed: 10/24/2017
• Issued: 11/13/2018
• Est. Priority Date: 10/24/2017
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Huang, Jiayin, Chen, Zhijun, Wang, Anchuan, Ingle, Nitin
• Primary Examiner(s): Malek, Maliheh
• Application Number:
  US15/792,290
• Time in Patent Office: 385 Days
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/401 containing silicon
• 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 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/4554 Plasma being used non-continuously in between ALD reactions C23C16/56 takes precedence
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01J 37/32422 Arrangement for selecting ions or species in the plasma
• 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 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02315 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288

Abstract

Exemplary methods for treating a silicon-containing substrate may include flowing plasma effluents of a hydrogen-containing precursor into a processing region of the semiconductor processing chamber. A silicon-containing substrate may be positioned within the processing region and include a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide exposing a portion of the silicon-containing substrate. The methods may include contacting the exposed portion of the silicon-containing substrate with the plasma effluents. The methods may include flowing an oxygen-containing precursor into the processing region of the semiconductor processing chamber. The methods may include contacting the exposed portion of the silicon-containing substrate with the oxygen-containing precursor. The methods may also include converting the exposed portion of the silicon-containing substrate to silicon oxide.

Claims

1. A method of treating a silicon-containing substrate, the method comprising:

flowing a hydrogen-containing precursor into a remote plasma region of a semiconductor processing chamber;

forming a plasma within the remote plasma region to generate plasma effluents of the hydrogen-containing precursor;

flowing the plasma effluents into a processing region of the semiconductor processing chamber, wherein a silicon-containing substrate is positioned within the processing region, and wherein the silicon-containing substrate comprises a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide exposing a portion of the silicon-containing substrate;

contacting the exposed portion of the silicon-containing substrate with the plasma effluents;

flowing an oxygen-containing precursor into the processing region of the semiconductor processing chamber;

contacting the exposed portion of the silicon-containing substrate with the oxygen-containing precursor; and

converting the exposed portion of the silicon-containing substrate to silicon oxide.

2. The method of treating a silicon-containing substrate of claim 1, further comprising laterally etching the layers of silicon nitride from sidewalls of the trench subsequent the converting.

3. The method of treating a silicon-containing substrate of claim 2, wherein the etching at least partially removes the converted silicon oxide.

4. The method of treating a silicon-containing substrate of claim 2, further comprising repeating the method for at least one additional cycle.

5. The method of treating a silicon-containing substrate of claim 4, wherein the silicon-containing substrate is etched less than 5 nm during the method.

6. The method of treating a silicon-containing substrate of claim 1, wherein the exposed portion of the silicon-containing substrate converted to silicon oxide is characterized by a thickness of silicon oxide less than or about 5 nm.

7. The method of treating a silicon-containing substrate of claim 1, wherein the exposed portion of the silicon-containing substrate converted to silicon oxide is beneath a layer of native oxide formed on the silicon-containing substrate.

8. The method of treating a silicon-containing substrate of claim 1, wherein the method is performed at a chamber operating pressure of less than or about 10 Torr.

9. The method of treating a silicon-containing substrate of claim 1, wherein the method is performed at a chamber temperature greater than or about 100°

C.

10. The method of treating a silicon-containing substrate of claim 1, wherein the oxygen-containing precursor is water vapor.

11. The method of treating a silicon-containing substrate of claim 10, wherein the water vapor is flowed into the processing region without plasma enhancement.

12. The method of treating a silicon-containing substrate of claim 1, wherein the hydrogen-containing precursor is hydrogen.

13. A method of treating a substrate, the method comprising:

forming a plasma within a remote plasma region of a semiconductor processing chamber containing a hydrogen-containing precursor to generate plasma effluents of the hydrogen-containing precursor;

flowing the plasma effluents into a processing region of the semiconductor processing chamber, wherein a substrate is positioned within the processing region, and wherein the substrate comprises a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide exposing a portion of the substrate;

contacting the exposed portion of the substrate with the plasma effluents;

flowing water vapor into the processing region of the semiconductor processing chamber;

contacting the exposed portion of the substrate with the water vapor; and

forming a layer of oxide on the exposed portion of the substrate.

14. The method of treating a substrate claim 13, further comprising laterally etching the layers of silicon nitride from sidewalls of the trench subsequent forming the layer of oxide.

15. The method of treating a substrate of claim 14, wherein the etching at least partially removes the layer of oxide.

16. The method of treating a substrate of claim 14, further comprising repeating the method.

17. The method of treating a substrate of claim 16, wherein repeating flowing the plasma effluents into the processing region of the semiconductor processing chamber comprises contacting exposed surfaces of the layers of silicon oxide with the plasma effluents.

18. The method of treating a substrate of claim 17, wherein the plasma effluents remove fluorine from the layers of silicon oxide.

19. The method of treating a substrate of claim 13, wherein the water vapor is flowed into the processing region without plasma enhancement.

20. The method of treating a substrate of claim 13, wherein the method is performed at a chamber temperature greater than or about 200°

C.