METHODS FOR FORMING SILICON GERMANIUM LAYERS

• US 20100317177A1
• Filed: 06/15/2010
• Published: 12/16/2010
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: ISHII, MASATO, HUANG, YI-CHIAU, SANCHEZ, ERROL
• Granted Patent: US 8,501,594 B2
• Time in Patent Office: Days
• US Class Current: 438/478
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: C30B 29/08 Germanium
• 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 21/02636 Selective deposition, e.g. simultaneous growth of mono- and non-monocrystalline semiconductor materials
• 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

Embodiments of methods for depositing silicon germanium (SiGe) layers on a substrate are disclosed herein. In some embodiments, the method may include depositing a first layer comprising silicon and germanium (e.g., a seed layer) atop the substrate using a first precursor comprising silicon and chlorine; and depositing a second layer comprising silicon and germanium (e.g., a bulk layer) atop the silicon germanium seed layer using a second precursor comprising silicon and hydrogen. In some embodiments, the first silicon precursor gas may comprise at least one of dichlorosilane (H₂SiCl₂), trichlorosilane (HSiCl₃), or silicon tetrachloride (SiCl₄). In some embodiments, the second silicon precursor gas may comprise at least one of silane (SiH₄), or disilane (Si₂H₆).

Claims

1. A method for depositing a silicon germanium layer on a substrate, comprising:

depositing a first layer comprising silicon and germanium atop the substrate using a first process gas mixture including a first silicon precursor comprising silicon and chlorine; and

depositing a second layer comprising silicon and germanium atop the first layer using a second process gas mixture including a second silicon precursor comprising silicon and hydrogen, wherein the first layer and the second layer form the silicon germanium layer.

2. The method of claim 1, wherein the first layer and the second layer are epitaxially grown.

3. The method of claim 1, wherein the first layer is deposited to a thickness of up to about 100 Angstroms.

4. The method of claim 1, wherein the second layer is deposited to a thickness of between about 200 to about 1000 Angstroms.

5. The method of claim 1, wherein the first silicon precursor gas comprises at least one of dichlorosilane (H₂SiCl₂), trichlorosilane (HSiCl₃), or silicon tetrachloride (SiCl₄).

6. The method of claim 1, wherein the second silicon precursor gas comprises at least one of silane (SiH₄) or disilane (Si₂H₆).

7. The method of claim 1, wherein the first silicon precursor gas is dichlorosilane and the second silicon precursor gas is silane.

8. The method of claim 1, wherein the substrate comprises silicon.

9. The method of claim 8, wherein a surface of the substrate is patterned.

10. The method of claim 9, wherein the first layer is deposited on an exposed silicon portion of the patterned substrate surface.

11. The method of claim 1, wherein the first layer is deposited at a first deposition rate and the second layer is deposited at a second deposition rate greater than the first deposition rate.

12. The method of claim 11, wherein the first deposition rate is between about 25 to about 150 Angstroms/minute.

13. The method of claim 11, wherein the second deposition rate is between about 150 to about 300 Angstroms/minute.

14. The method of claim 1, wherein the concentration of germanium in the first layer is between about 10 to about 35 percent, and wherein the concentration of germanium in the second layer is between about 10 to about 35 percent.

15. The method of claim 1, wherein the concentrations of germanium in the first layer and the second layer are substantially equal.

16. The method of claim 1, wherein at least one of the first process gas mixture and the second process gas mixture further comprises a dilutant/carrier gas.

17. The method of claim 16, wherein the dilutant/carrier gas comprises at least one of hydrogen (H₂), nitrogen (N₂), helium (He), or argon (Ar).

18. The method of claim 1, wherein at least one of the first process gas mixture and the second process gas mixture further comprises an etch gas.

19. The method of claim 18, wherein the etch gas comprises at least one of hydrogen chloride (HCl) or chlorine (Cl₂).

20. A computer readable medium having instructions stored thereon that, when executed by a processor, causes a semiconductor process tool to perform a method of forming a silicon germanium layer, comprising:

depositing a first layer comprising silicon and germanium atop the substrate using a first precursor comprising silicon and chlorine; and

depositing a second layer comprising silicon and germanium atop the first layer using a second precursor comprising silicon and hydrogen, wherein the first layer and the second layer form the silicon germanium layer.