Selective growth of silicon nitride

• US 10,490,413 B2
• Filed: 01/23/2018
• Issued: 11/26/2019
• Est. Priority Date: 03/17/2017
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Smith, David Charles, Hausmann, Dennis M.
• Primary Examiner(s): McCall-Shepard, Sonya D.
• Application Number:
  US15/878,349
• Publication Number:
  US 20180269058A1
• Time in Patent Office: 672 Days
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/32 using masks
• CPC Class Codes: H01L 21/321 After treatment

Abstract

Methods and apparatuses for selectively depositing silicon nitride on silicon surfaces relative to silicon oxide surfaces and selectively depositing silicon nitride on silicon oxide surfaces relative to silicon surfaces are provided herein. Methods involve blocking one surface while leaving another surface unblocked and selectively depositing silicon nitride on the unblocked surface. The blocked surface may include an organic moiety having an Si—C bond. The method may include blocking one of an exposed hydroxyl-terminated silicon-containing surface and an exposed hydrogen-terminated silicon-containing surface of the substrate. Apparatuses include a process chamber having a pedestal, an outlet, and a controller for providing instructions for causing delivery of a semiconductor substrate to the pedestal, causing introduction of a silicon-containing precursor and causing introduction of a nitrogen-containing reactant without igniting a plasma.

Claims

1. A method of depositing silicon nitride on a semiconductor substrate, the method comprising:

providing the semiconductor substrate having a blocked surface and an unblocked surface, the blocked surface comprising an organic moiety having an Si—

C bond; and

selectively depositing silicon nitride on the unblocked surface by one or more thermal atomic layer deposition cycles, each cycle comprising;

exposing the semiconductor substrate having the blocked and unblocked surfaces to a silicon-containing precursor to adsorb the silicon-containing precursor to the unblocked surface; and

exposing the semiconductor substrate to a nitrogen-containing reactant without igniting a plasma to form silicon nitride selectively on the unblocked surface relative to the blocked surface.

2. The method of claim 1, wherein the unblocked surface is a non-silicon surface.

3. The method of claim 1, wherein the unblocked surface is a non-silicon-oxide surface.

4. The method of claim 1, wherein the unblocked surface comprises hydroxyl groups.

5. The method of claim 1, further comprising preparing the blocked surface by exposing the semiconductor substrate to an alkene.

6. The method of claim 5, wherein the alkene is 1-octadecene.

7. The method of claim 1, further comprising preparing the blocked surface by exposing the semiconductor substrate to an alkylsilylhalide having a chemical structure

8. The method of claim 7, wherein the alkylsilylhalide is octadecyltrichlorosilane.

9. The method of claim 7, further comprising, after selectively depositing the silicon nitride, removing the organic moiety by exposing the semiconductor substrate to a mixture of a fluorine-containing gas and an oxygen-containing gas and igniting a plasma at a plasma power between about 75 W and about 200 W.

10. The method of claim 9, wherein the plasma is ignited in a remote plasma generator.

11. The method of claim 9, wherein the plasma is ignited in situ.

12. The method of claim 1, further comprising, after selectively depositing the silicon nitride, removing the organic moiety.

13. The method of claim 12, wherein removing the organic moiety comprises exposing the semiconductor substrate to an inert gas selected from the group consisting of helium and argon and igniting a plasma at a plasma power between about 500 W and about 2000 W.

14. A method of depositing silicon nitride on a semiconductor substrate, the method comprising:

providing the semiconductor substrate having an exposed hydroxyl-terminated silicon-containing surface and an exposed hydrogen-terminated silicon-containing surface;

exposing the semiconductor substrate to a blocking reagent to block one of the exposed hydroxyl-terminated silicon-containing surface and the exposed hydrogen-terminated silicon-containing surface by forming an organic moiety on the one of the exposed hydroxyl-terminated silicon-containing surface and the exposed hydrogen-terminated silicon-containing surface while the other of the exposed hydroxyl-terminated silicon-containing surface and the exposed hydrogen-terminated silicon-containing surface remains unblocked; and

selectively depositing silicon nitride on the other of the exposed hydroxyl-terminated silicon-containing surface and the exposed hydrogen-terminated silicon-containing surface by one or more thermal atomic layer deposition cycles, each cycle comprising;

exposing the semiconductor substrate having the blocked and unblocked surfaces to a silicon-containing precursor to adsorb the silicon-containing precursor to the unblocked surface; and

exposing the semiconductor substrate to a nitrogen-containing reactant without igniting a plasma to form silicon nitride selectively on the unblocked surface relative to the blocked surface.

15. The method of claim 14, further comprising, prior to exposing the semiconductor substrate to the blocking reagent, exposing the semiconductor substrate to hydrogen to form the exposed hydrogen-terminated silicon-containing surface.

16. The method of claim 14, further comprising, prior to exposing the semiconductor substrate to the blocking reagent, exposing the semiconductor substrate to ambient air to form the exposed hydroxyl-terminated silicon-containing surface.

17. The method of claim 14, further comprising, prior to exposing the semiconductor substrate to the blocking reagent, exposing the semiconductor substrate to 1% hydrofluoric acid diluted in water to form the exposed hydroxyl-terminated silicon-containing surface.

18. The method of claim 14, wherein the blocking reagent is an alkene.

19. The method of claim 14, wherein the blocking reagent is an alkylsilylhalide having a chemical structure