Abbreviated GaN metalorganic vapor phase epitaxy growth mode on nano-patterned sapphire for enhanced efficiency of InGaN-based light-emitting diodes

Abstract

Metalorganic vapor phase epitaxy (MOVPE) nucleation studies of GaN on planar sapphire and nano-patterned AGOG (Deposition of Aluminum, Growth of Oxide, and Grain growth) sapphire substrates were conducted. The use of abbreviated GaN growth mode, which utilizes a process of using 15nm low temperature GaN buffer and bypassing etchback and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.