Effect of aluminum carbide buffer layer on growth and self-separation ofm-plane GaN by hydride vapor phase epitaxy

✍ Scribed by Sasaki, Hitoshi ;Sunakawa, Haruo ;Sumi, Norihiko ;Yamamoto, Kazutomi ;Usui, Akira

• Book ID: 105365212
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 453 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200880834

✦ Synopsis

Abstract

An m ‐plane GaN layer with a thickness of approximately 500 μm was successfully obtained on a conventional m ‐plane sapphire substrate with a diameter of 2 inches. The GaN layer was grown by hydride vapor phase epitaxy (HVPE) on a buffer layer of low‐temperature (LT) GaN/Al~4~C~3~ structure deposited on the sapphire substrate by metalorganic chemical vapor deposition (MOCVD). The deposition temperature of the Al~4~C~3~ layer affected the appearance of the m ‐plane GaN layer. The c‐axes of the GaN layer is parallel to the a‐axis of the sapphire substrate. The thick GaN layer spontaneously separated from the sapphire substrate after its growth. Complete self‐separation of the m ‐plane GaN from the sapphire substrate was achieved with good reproducibility when the thickness of the Al~4~C~3~ layer was 70–100 nm. By lapping and polishing the self‐separated GaN crystal, a freestanding m ‐plane GaN wafer with a diameter of 45 mm was obtained. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)