Pre-clean of silicon germanium for pre-metal contact at source and drain and pre-high K at channel

• US 10,615,034 B2
• Filed: 12/26/2018
• Issued: 04/07/2020
• Est. Priority Date: 09/15/2014
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Zheng, Bo, Gelatos, Avgerinos V., Vyas, Anshul, Hung, Raymond Hoiman
• Primary Examiner(s): Movva, Amar
• Application Number:
  US16/232,609
• Publication Number:
  US 20190326115A1
• Time in Patent Office: 468 Days
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/481 by radiant heating of the substrate
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02049 with gaseous HF
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/02661 In-situ cleaning
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/67184 characterized by the presence of more than one transfer chamber
• CPC Class Codes: H01L 21/67207 comprising a chamber adapted to a particular process

Abstract

The present disclosure generally relates to methods for removing contaminants and native oxides from substrate surfaces. The method includes exposing a surface of the substrate to first hydrogen radical species, wherein the substrate is silicon germanium having a concentration of germanium above about 30%, then exposing the surface of the substrate to a plasma formed from a fluorine-containing precursor and a hydrogen-containing precursor, and then exposing the surface of the substrate to second hydrogen radical species.

Claims

1. A method for processing a substrate, comprising:

exposing a surface of the substrate to hydrogen radical species;

exposing the surface of the substrate to a plasma formed from a first fluorine-containing precursor and a first hydrogen-containing precursor;

annealing the substrate;

forming an epitaxial layer on the surface of the substrate; and

between annealing the substrate and forming an epitaxial layer on the surface of the substrate, exposing the surface of the substrate to a plasma formed from a second fluorine-containing precursor and a second hydrogen-containing precursor in a first processing chamber.

2. The method of claim 1, wherein the substrate is silicon germanium having a concentration of germanium in silicon above about 30%.

3. The method of claim 1, wherein the hydrogen radical species are formed by exposing a hydrogen-containing gas to a hot wire chemical vapor deposition (HWCVD) source.

4. The method of claim 1, wherein the hydrogen radical species are formed by exposing a hydrogen-containing gas to a UV light.

5. The method of claim 1, wherein exposing the surface of the substrate to hydrogen radical species is performed in a first processing chamber.

6. The method of claim 5, wherein the hydrogen radical species are formed in a remote plasma source separated from the first processing chamber.

7. The method of claim 5, wherein exposing a surface of the substrate to a plasma formed from a first fluorine-containing precursor and a first hydrogen-containing precursor is performed in the first processing chamber.

8. The method of claim 7, wherein exposing the surface of the substrate to a plasma formed from a first fluorine-containing precursor and a first hydrogen-containing precursor is performed in a second processing chamber.

9. The method of claim 8, wherein forming an epitaxial layer on the surface of the substrate in performed in a third processing chamber.

10. The method of claim 9, wherein the substrate is transferred between the first, second, and third processing chambers within one processing system without breaking vacuum.

11. The method of claim 1, wherein the substrate comprises doped silicon, undoped silicon, polysilicon, crystalline silicon, silicon oxide, strained silicon, silicon germanium, doped polysilicon, germanium, sapphire (Al₂O₃), silicon carbide (SiC), spinel, zinc oxide, gallium-arsenide (GaAs), lithium gallate, indium phosphide (InP), single-crystal GaN, aluminum nitride (AlN), GdScO₃ (GSO), MoSe₂, Ge₂Sb₂Te₅ (GST), or combinations thereof.

12. The method of claim 1, wherein the first and second fluorine-containing precursors comprise nitrogen trifluoride (NF₃), hydrogen fluoride (HF), diatomic fluorine (F₂), monatomic fluorine (F) and fluorine-substituted hydrocarbons, or combinations thereof.

13. A method for processing a substrate, comprising:

exposing a surface of the substrate to a plurality of plasma treatments, wherein one or more of the plasma treatments comprise exposing the surface of the substrate to a plasma formed from a fluorine-containing precursor and a hydrogen-containing precursor;

exposing the surface of the substrate to hydrogen radical species between at least two of the plurality of plasma treatments;

and then

forming an epitaxial layer on the surface of the substrate.

14. The method of claim 13, further comprising

annealing the substrate between plasma treatments.

15. The method of claim 13, wherein the substrate is silicon germanium having a concentration of germanium in silicon above about 30%.

16. The method of claim 13, wherein the hydrogen radical species are formed by exposing a hydrogen-containing gas to a hot wire chemical vapor deposition (HWCVD) source.

17. The method of claim 13, wherein the hydrogen radical species are formed by exposing a hydrogen-containing gas to a UV light.

18. A method for processing a substrate, comprising:

performing a plurality of contaminant removal processes on a surface of a substrate, wherein each contaminant removal process comprises exposing the surface of the substrate to plasma formed radical species of a fluorine-containing precursor and a hydrogen-containing precursor;

between contaminant removal processes, treating the surface of the substrate with a pre-treatment process comprising exposing a surface of the substrate to hydrogen radical species; and

then

forming an epitaxial layer on the surface of the substrate.

19. The method of claim 18, wherein the substrate is silicon germanium having a concentration of germanium in silicon above about 30%.