m-Plane GaInN Light Emitting Diodes Grown on Patterneda-Plane Sapphire Substrates

Abstract

The fabrication of a blue m-plane GaInN light emitting diode (LED) grown on an m-plane GaN layer grown on a 3-in. patterned sapphire substrate is reported. The output power of the LED was approximately 3 mW at the wavelength of 461 nm, a driving current of 20 mA, and a forward voltage of 3.5 V. This is the first report of nonpolar or semipolar blue LEDs grown on hetero-substrates with milliwatt scale output power.

Growth evolution and microstructural characterization of semipolar (112̄2) GaN selectively grown on etched r-plane sapphire

“…This method has also been applied to currently more commonly used sapphire substrates [13][14][15][16]. Using this method, Saito et al [17] have produced mW range heteroepitaxial m-plane LEDs using stripe etched a-plane sapphire substrates. For growth of semipolar (112 2) GaN, as shown schematically in Fig.…”

Crystallographic Wet Chemical Etching of Semipolar GaN (11–22) Grown on <I>m</I>-Plane Sapphire Substrates

“…Figure 1(a) shows the XRD pattern of semipolar GaN with thickness of 2 m for X-ray incident toward the direction. The surface orientation of the sample was confirmed to be (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN. Figure 1(b) shows a schematic diagram of the direction, such as (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN on m-plane sapphire.…”

“…The surface orientation of the sample was confirmed to be (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN. Figure 1(b) shows a schematic diagram of the direction, such as (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN on m-plane sapphire. As reported by Baker et al the in-plane epitaxial relationship for (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN was [11][12][13][14][15][16][17][18][19][20][21] GaN 0001 sapphire and [1100] GaN sapphire.…”

“…[3][4][5][6] The absence of an internal electric field in nonpolar and semipolar GaN light emitting diodes (LEDs) is advantageous for achieving not only highly-efficient light emitters with thicker QWs, but also improved wavelength stability with injection currents. [7][8][9][10][11][12][13][14] On the other hand, to fabricate LEDs, it is important to develop well-defined etching processes that can allow reliable pattern transfer for a range of GaN planes. Most III-nitride etching currently performed employs dry * Author to whom correspondence should be addressed.…”

Electron channeling contrast imaging studies of nonpolar nitrides using a scanning electron microscope

“…4,5 On top of performance issues, cost is an important factor for producing viable device structures. To date, m-plane III-nitride LEDs have been grown on substrates such as Si, 6 m-plane SiC, 7 free standing m-plane GaN, 8 a-plane sapphire, 9 r-plane sapphire, 10,11 and c-LiAlO 2 . 4,12 Amongst these substrates, the use of Si and c-LiAlO 2 are considered to be the most economically viable.…”