NUCLEATION OF ALUMINUM NITRIDE ON A SILICON SUBSTRATE USING AN AMMONIA PREFLOW

• US 20140318443A1
• Filed: 07/07/2014
• Published: 10/30/2014
• Est. Priority Date: 07/25/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Manutius IP, Inc.
• Inventors: FENWICK, William E., RAMER, Jeff
• Granted Patent: US 9,617,656 B2
• Time in Patent Office: Days
• US Class Current: 117/102
• CPC Class Codes: C30B 25/10 Heating of the reaction chamber or the substrate
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: C30B 25/183 being provided with a buffer layer, e.g. a lattice matching layer
• CPC Class Codes: C30B 25/186 being specially pre-treated by, e.g. chemical or physical means
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02502 consisting of two layers
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/0075 comprising nitride compounds

Abstract

A silicon wafer used in manufacturing crystalline GaN for light emitting diodes (LEDs) includes a silicon substrate, a buffer layer of aluminum nitride (AlN) and an upper layer of GaN, the silicon wafer has a diameter of at least 200 millimeters and an Si(111)1×1 surface. The AlN buffer layer overlies the Si(111) surface. The GaN upper layer is disposed above the buffer layer, Across the entire wafer substantially no aluminum atoms of the AlN are present in a bottom most plane of atoms of the AlN, and across the entire wafer substantially only nitrogen atoms of the AlN are present in the bottom most plane of atoms of the AlN. A method of making the AlN buffer layer includes preflowing a first amount of ammonia equaling less than 0.01% by volume of hydrogen flowing through a chamber before flowing trimethylaluminum and then a subsequent amount of ammonia through the chamber.

Claims

1-7. -7. (canceled)

8. A method comprising:

(a) heating a substrate of silicon (Si) to a temperature above 950°

C. in a chamber;

(b) flowing hydrogen (H₂) into the chamber;

(c) flowing a first amount of ammonia (NH₃) into the chamber while the hydrogen is still flowing into the chamber, wherein the first amount of ammonia is less than 0.01% by volume of the hydrogen flowing into the chamber;

(d) flowing trimethylaluminum (Al₂(CH₃)₆) into the chamber while the hydrogen is still flowing into the chamber; and

(e) flowing a subsequent amount of ammonia into the chamber while the trimethylaluminum is still flowing into the chamber, wherein the subsequent amount of ammonia is greater than 0.002% by volume of the hydrogen flowing into the chamber.

9. The method of claim 8, wherein the flowing the first amount of ammonia into the chamber is performed for between thirty seconds to three minutes.

10. The method of claim 8, wherein the substrate is a wafer having a surface, and wherein the first amount of ammonia does not exceed 0.006 cubic centimeters per minute over each square centimeter of the surface of the substrate.

11. The method of claim 8, wherein the substrate is a wafer having a surface, and wherein the flowing the hydrogen into the chamber is performed by flowing between 106 and 118 cubic centimeters of hydrogen per minute over each square centimeter of the surface of the substrate.

12. The method of claim 8, wherein the flowing the trimethylaluminum into the chamber is performed for between ten to twenty minutes.

13. The method of claim 8, wherein trimethylaluminum flows into the chamber in an amount of about ninety micromoles per minute.

14. The method of claim 8, wherein the temperature in the chamber during the flowing of hydrogen in (b) is above 1100°

C., and wherein the temperature in the chamber during the flowing of the first amount of ammonia in (c) is between 1000°

C. and 1050°

C.

21. The method of claim 8, wherein the flowing the first amount of ammonia into the chamber is performed before the flowing the trimethylaluminum into the chamber.

15-20. -20. (canceled)