Methods and Mask Structures for Substantially Defect-Free Epitaxial Growth

• US 20130233238A1
• Filed: 02/15/2013
• Published: 09/12/2013
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: IMEC International
• Original Assignee: IMEC International
• Inventors: Vincent, Benjamin, Witters, Liesbeth, Thean, Aaron
• Granted Patent: US 9,476,143 B2
• Time in Patent Office: Days
• US Class Current: 117/58
• CPC Class Codes: C30B 19/00 Liquid-phase epitaxial-layer growth
• CPC Class Codes: C30B 19/12 characterised by the substrate
• CPC Class Codes: C30B 23/04 Pattern deposit, e.g. by using masks
• CPC Class Codes: C30B 25/04 Pattern deposit, e.g. by using masks
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02538 Group 13/15 materials
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/02647 Lateral overgrowth
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/762 Dielectric regions , e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7851 with the body tied to the substrate

Abstract

Disclosed are methods and mask structures for epitaxially growing substantially defect-free semiconductor material. In some embodiments, the method may comprise providing a substrate comprising a first crystalline material, where the first crystalline material has a first lattice constant; providing a mask structure on the substrate, where the mask structure comprises a first level comprising a first opening extending through the first level (where a bottom of the first opening comprises the substrate), and a second level on top of the first level, where the second level comprises a plurality of second trenches positioned at a non-zero angle with respect to the first opening. The method may further comprise epitaxially growing a second crystalline material on the bottom of the first opening, where the second crystalline material has a second lattice constant different than the first lattice constant and defects in the second crystalline material are trapped in the first opening.

Claims

1. A method comprising:

providing a substrate comprising a first crystalline material, wherein the first crystalline material has a first lattice constant;

providing a mask structure on the substrate, wherein the mask structure comprises;

a first level comprising a first opening extending through the first level, wherein a bottom of the first opening comprises the substrate, and

a second level on top of the first level, wherein the second level comprises a plurality of second trenches positioned at a non-zero angle with respect to the first opening; and

epitaxially growing a second crystalline material on the bottom of the first opening until the second crystalline material covers at least a portion of the plurality of second trenches, wherein;

the second crystalline material has a second lattice constant different than the first lattice constant, and

epitaxially growing the second crystalline material on the bottom of the first opening comprises trapping defects in the second crystalline material in at least one direction in the first opening.

2. The method of claim 1, wherein the non-zero angle comprises substantially 90°

.

3. The method of claim 1, wherein the plurality of second trenches comprises two arrays of second trenches separated by the first opening.

4. The method of claim 1, wherein the plurality of second trenches extend continuously across the first opening.

5. The method of claim 1, wherein the first opening comprises a first trench.

6. The method of claim 1, wherein the first opening comprises a plurality of first openings.

7. The method of claim 1, wherein epitaxially growing the second crystalline material until the second crystalline material covers at least a portion of the plurality of second trenches comprises growing the second crystalline material until the second crystalline material overgrows the plurality of second trenches.

8. The method of claim 7, further comprising planarizing the second crystalline material.

9. The method of claim 1, wherein the at least one direction in the first opening comprises a direction along a length of the first opening.

10. The method of claim 1, wherein each of the first crystalline material and the second crystalline material comprises a semiconductor material.

11. A method comprising:

providing a substrate comprising a first crystalline material, wherein the first crystalline material has a first lattice constant;

providing a mask structure on the substrate, wherein the mask structure comprises;

a first level comprising a first opening extending through the first level, wherein a bottom of the first opening comprises the substrate, and

a second level on top of the first level, wherein the second level comprises two barriers positioned on opposite sides of the first opening; and

epitaxially growing a second crystalline material on the bottom of the first opening until the second crystalline material covers at least a portion of the two barriers, wherein;

the second crystalline material has a second lattice constant different than the first lattice constant, and

epitaxially growing the second crystalline material on the bottom of the first opening comprises trapping defects in the second crystalline material in at least one direction in the first opening.

12. The method of claim 11, wherein:

the first level further comprises an array of first openings including the first opening; and

the second level further comprises an array of barriers including the two barriers, wherein barriers in the array of barriers are positioned on opposite sides of first openings in the array of first openings.

13. The method of claim 12, wherein epitaxially growing the second crystalline material until the second crystalline material covers at least a portion of the two barriers comprises growing the second crystalline material until the second crystalline material overgrows the two barriers.

14. The method of claim 13, further comprising planarizing the second crystalline material.

15. A mask structure comprising:

a first level comprising a first opening extending through the first level, wherein a bottom of the first opening comprises the substrate, and

a second level on top of the first level, wherein the second level comprises a plurality of second trenches positioned at a non-zero angle with respect to the first opening, wherein the mask structure is configured for epitaxial growth of a second crystalline material on the bottom of the first opening until the second crystalline material covers at least a portion of the plurality of second trenches.

16. The mask structure of claim 15, wherein the first opening has a height that is at least three times a width of the first opening.

17. The mask structure of claim 15, wherein:

the plurality of second trenches comprises an array of second trenches; and

the array is positioned at a non-zero angle with respect to the first opening.

20. The mask structure of claim 15, wherein the second level further comprises two additional barriers positioned on additional opposite sides of the first opening such that the two barriers and the two additional barriers are positioned concentrically around the first opening.

18. A mask structure comprising:

a first level comprising a first opening extending through the first level, wherein a bottom of the first opening comprises the substrate, and

a second level on top of the first level, wherein the second level comprises two barriers positioned on opposite sides of the first opening, wherein the mask structure is configured for epitaxial growth of a second crystalline material on the bottom of the first opening until the second crystalline material covers at least a portion of the barriers.

19. The mask structure of claim 18, wherein the first opening has a height that is at least three times a width of the first opening.