METHODS OF FORMING A LAYER OF SILICON ON A LAYER OF SILICON/GERMANIUM

• US 20140057415A1
• Filed: 08/24/2012
• Published: 02/27/2014
• Est. Priority Date: 08/24/2012
• Status: Active Grant

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Kronholz, Stephan, Patzer, Joachim
• Granted Patent: US 8,969,190 B2
• Time in Patent Office: Days
• US Class Current: 438/478
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0245 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/66636 with source or drain recessed by etching or first recessed by etching and then refilled
• CPC Class Codes: H01L 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 29/7848 the means being located in the source/drain region, e.g. SiGe source and drain

Abstract

Disclosed herein are various methods of forming a layer of silicon on a layer of silicon/germanium. In one example, a method disclosed herein includes forming a silicon/germanium material on a semiconducting substrate, after forming the silicon/germanium material, performing a heating process to raise a temperature of the substrate to a desired silicon formation temperature while flowing a silicon-containing precursor and a chlorine-containing precursor into the deposition chamber during the heating process, and, after the temperature of the substrate reaches the desired silicon formation temperature, forming a layer of silicon on the silicon/germanium material.

Claims

1. A method of forming a transistor, comprising:

performing a deposition process in a deposition chamber to form a silicon/germanium material on a semiconducting substrate;

after forming said silicon/germanium material, performing a heating process to raise a temperature of the substrate to a desired silicon formation temperature while flowing a silicon-containing precursor and a chlorine-containing precursor into said deposition chamber during said heating process; and

after said temperature of said substrate reaches said desired silicon formation temperature, forming a layer of silicon on said silicon/germanium material.

2. The method of claim 1, wherein forming said layer of silicon/germanium comprises forming a single layer of silicon/germanium.

3. The method of claim 1, wherein forming said layer of silicon/germanium comprises forming multiple layers of silicon/germanium.

4. The method of claim 3, wherein each of said multiple layers of silicon/germanium have a different germanium content.

5. The method of claim 1, wherein said silicon/germanium material has a germanium concentration that falls within the range of 15-50%.

6. The method of claim 1, wherein said desired silicon formation temperature falls within the range of about 750-900°

C.

7. The method of claim 6, wherein said silicon-containing precursor is comprised of one of silane (SiH₄), dichlorosilane (H₂SiCl₂,”

) or trichlorsilane.

8. The method of claim 7, wherein a flow rate of said silicon-containing precursor falls within the range of about 50-500 sscm.

9. The method of claim 7, wherein said chlorine-containing precursor is comprised of one of hydrogen chlorine (HCl) or chlorine (Cl₂).

10. The method of claim 9, wherein a flow rate of said chlorine-containing precursor falls within the range of about 50-500 sscm.

11. The method of claim 1, further comprising flowing hydrogen into said chamber during said heating process.

12. The method of claim 11, wherein a flow rate of said hydrogen falls within the range of about 50-500 sscm.

13. A method of forming a transistor, comprising:

performing a first deposition process in a deposition chamber to form a silicon/germanium material on a semiconducting substrate at a first deposition temperature that falls within the range of about 680-750°

C.;

after forming said silicon/germanium material, performing a heating process to raise a temperature of said substrate to a desired silicon formation temperature that falls within the range of about 750-900°

C. while flowing a silicon-containing precursor and a chlorine-containing precursor into said deposition chamber during said heating process; and

after said temperature of said substrate reaches said desired silicon formation temperature, forming a layer of silicon on said silicon/germanium material.

14. The method of claim 13, wherein said silicon/germanium material has a germanium concentration that falls within the range of 15-50%.

15. The method of claim 13, wherein said silicon-containing precursor is comprised of one of silane (SiH₄), dichlorosilane (H₂SiCl₂) or trichlorsilane.

16. The method of claim 15, wherein a flow rate of said silicon-containing precursor falls within the range of about 50-500 sscm.

17. The method of claim 13, wherein said chlorine-containing precursor is comprised of one of hydrogen chlorine (HCl) or chlorine (Cl₂).

18. The method of claim 17, wherein a flow rate of said chlorine-containing precursor falls within the range of about 50-500 sscm.

19. The method or claim 17, further comprising flowing hydrogen into said chamber during said heating process.

20. The method of claim 19, wherein a flow rate of said hydrogen falls within the range of about 50-500 sscm.

21. A method of forming a transistor, comprising:

performing a first deposition process in a deposition chamber to form a silicon/germanium material on a semiconducting substrate at a first deposition temperature that falls within the range of about 680-750°

C.;

after forming said silicon/germanium material, performing a heating process to raise a temperature of said substrate to a desired silicon formation temperature that falls within the range of about 750-900°

C. while flowing a silicon-containing precursor, a chlorine-containing precursor and hydrogen into said deposition chamber during said heating process, wherein a flow rate of said silicon-containing precursor, said chlorine-containing precursor and said hydrogen falls within the range of about 50-500 sscm, 50-500 sscm and 50-500 sscm, respectively; and

after said substrate reaches said desired silicon formation temperature, forming a layer of silicon on said silicon/germanium material.

22. The method of claim 21, wherein said silicon/germanium material has a germanium concentration that falls within the range of 15-50%.

23. The method of claim 21, wherein said silicon-containing precursor is comprised of one of silane (SiH₄), dichlorosilane (H₂SiCl₂,”

) or trichlorsilane.

24. The method of claim 21, wherein said chlorine-containing precursor is comprised of one of hydrogen chlorine (HCl) or chlorine (Cl₂).