SURFACE MODIFICATION TO IMPROVE AMORPHOUS SILICON GAPFILL

• US 20200075329A1
• Filed: 11/11/2019
• Published: 03/05/2020
• Est. Priority Date: 04/07/2017
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: MANNA, Pramit, JIANG, Shishi, MALLICK, Abhijit Basu
• Granted Patent: US 10,643,841 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02592 amorphous
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264

Abstract

Methods for gapfilling semiconductor device features, such as high aspect ratio trenches, with amorphous silicon (a-Si) film that involves pretreating the surface of the substrate to modify the underlying hydroxy-terminated silicon (Si—OH) or hydrogen-terminated silicon (Si—H) surface to oxynitride-terminated silicon (Si—ON) or nitride-terminated silicon (Si—N) and enhance the subsequent a-Si deposition are provided. First, a substrate having features formed in a first surface of the substrate is provided. The surface of the substrate is then pretreated to enhance the surface of the substrate for the flowable deposition of amorphous silicon that follows. A flowable deposition process is then performed to deposit a flowable silicon layer over the surface of the substrate. Methods described herein generally improve overall etch selectivity by the conformal silicon deposition and the flowable silicon deposition process to realize seam-free gapfilling between features with high quality amorphous silicon film.

Claims

1. A semiconductor device, comprising:

a substrate having at least one feature formed in a surface of the substrate, wherein the at least one feature is defined by sidewalls and a bottom surface;

an oxynitride-terminated silicon layer disposed over the surface of the substrate and the sidewalls and the bottom surface of the at least one feature; and

a flowable silicon film disposed over the oxynitride-terminated silicon layer, wherein the flowable silicon film fills the at least one feature and comprises amorphous silicon.

2. The semiconductor device of claim 1, wherein the at least one feature has an aspect ratio of 5:

1 or more.

3. The semiconductor device of claim 1, wherein the at least one feature has an aspect ratio of greater than or equal to 10:

1.

4. The semiconductor device of claim 1, wherein the oxynitride-terminated silicon layer is disposed on and in contact with the surface of the substrate and the sidewalls and the bottom surface of the at least one feature.

5. The semiconductor device of claim 4, wherein the flowable silicon film is disposed on and in contact with the oxynitride-terminated silicon layer and fills the at least one feature.

6. The semiconductor device of claim 5, wherein the flowable silicon film filling the at least one feature is seam-free.

7. The semiconductor device of claim 1, wherein the flowable silicon film has a Hydrogen concentration of greater than about 30%.

8. A semiconductor device, comprising:

a substrate having at least one feature formed in a surface of the substrate, wherein the at least one feature is defined by sidewalls and a bottom surface;

a nitride-terminated-silicon layer disposed over the surface of the substrate and the sidewalls and the bottom surface of the at least one feature; and

a flowable silicon film disposed over the nitride-terminated-silicon layer, wherein the flowable silicon film fills the at least one feature and comprises amorphous silicon.

9. The semiconductor device of claim 8, wherein the at least one feature has an aspect ratio of 5:

1 or more.

10. The semiconductor device of claim 8, wherein the at least one feature has an aspect ratio of greater than or equal to 10:

1.

11. The semiconductor device of claim 8, wherein the nitride-terminated-silicon layer is disposed on and in contact with the surface of the substrate and the sidewalls and the bottom surface of the at least one feature.

12. The semiconductor device of claim 11, wherein the flowable silicon film is disposed on and in contact with the nitride-terminated-silicon layer and fills the at least one feature.

13. The semiconductor device of claim 12, wherein the flowable silicon film filling the at least one feature is seam-free.

14. The semiconductor device of claim 8, wherein the flowable silicon film has a Hydrogen concentration of greater than about 30%.

15. A semiconductor device, comprising:

a substrate having at least one feature formed in a surface of the substrate, wherein the at least one feature is defined by sidewalls and a bottom surface;

a silicon pretreated surface layer disposed over the surface of the substrate and the sidewalls and the bottom surface of the at least one feature; and

a flowable silicon film disposed over the silicon pretreated surface layer, wherein the flowable silicon film fills the at least one feature and comprises amorphous silicon.

16. The semiconductor device of claim 15, wherein the silicon pretreated surface layer is an oxynitride-terminated silicon layer or a nitride-terminated-silicon layer.

17. The semiconductor device of claim 15, wherein the at least one feature has an aspect ratio of greater than or equal to 10:

1.

18. The semiconductor device of claim 15, wherein

the silicon pretreated surface layer is disposed on and in contact with the surface of the substrate and the sidewalls and the bottom surface of the at least one feature, and

the flowable silicon film is disposed on and in contact with the silicon pretreated surface layer and fills the at least one feature.

19. The semiconductor device of claim 18, wherein the flowable silicon film filling the at least one feature is seam-free.

20. The semiconductor device of claim 15, wherein the flowable silicon film has a Hydrogen concentration of greater than about 30%.