High quality nitride semiconductors grown on novel ScAlMgO₄ substrates and their light emitting diodes

Abstract

III-N semiconductors growth on high quality ScAlMgO 4 (SCAMO) substrates was studied. The GaN epitaxial layer grown on the SCAMO substrate showed a low defect density of 5.6 × 10 7 cm −2 evaluated by cathode luminescence and had a distinct improvement in crystallinity compared to the GaN layer on a sapphire substrate. LEDs on both SCAMO and sapphire substrates were grown, and their optical properties were compared. The LED on the SCAMO substrate showed high luminescence efficiency by photoluminescence, and it was 14.3% at 300 K. Bright emission from the LED on the SCAMO substrate was observed under current injection and the electroluminescence properties revealed that the external efficiency of the LED on the SCAMO substrate was 15% higher than that of the LED on the sapphire substrate.

Research Progress of ScAlMgO4 Crystal: a Novel GaN and ZnO Substrate

“…Ohnishi [58] 等采用 AFM 对其表面的粗糙度进行测试， 如图 11(h)。在 20×20 μm 2 的区域内，其平均粗糙度 (Ra)为 0.08 nm，表明通过刀片剥离的 SCAM 表面为 原子级平面。因此，SCAM 衬底是生长高质量 GaN 外延薄膜的最佳选择 [48,[58][59][60] 。 图 11 SCAM 衬底的再利用过程 [58] Fig. 11 SCAM substrate reuse process [58] (a [79][80][81][82] 。因此采 用低温生长方法对于以 SCAM 为衬底获得高质量 GaN 薄膜至关重要。 脉冲激光沉积(Pulsed Laser Deposition, PLD)技 术采用脉冲激光烧蚀 GaN 靶材会导致在衬底表面迁 移的前驱体具有较高的能量 [80,[83][84] ，使薄膜可以在 较低的温度下进行外延生长。2016 年 Wang 等 [85] [85] Fig.…”

Recent progress in red light-emitting diodes by III-nitride materials

“…A c c e p t e d M a n u s c r i p t with In0.17Ga0.83N and 1.8% lattice-mismatched with GaN. Using MOVPE growth, InGaNbased blue LEDs on (0001) ScAlMgO4 substrates were demonstrated [90,91]. GaN layers can be obtained with high crystal quality, which is comparable with GaN on sapphire [90,92].…”

Substrate Terrace Width Dependence of Direct Growth of GaN on ScAlMgO4 by Radio‐Frequency Molecular Beam Epitaxy

“…[ 1,14,15 ] Several studies have considered the growth of (In)GaN on SAM substrates using hydride vapor phase epitaxy (HVPE), [ 1,14,15 ] metal–organic VPE (MOVPE), [ 7,8,18–21 ] molecular beam epitaxy (MBE), [ 22,23 ] and pulsed‐laser deposition (PLD), [ 24,25 ] and the fabrication of light‐emitting diode (LED) structures. [ 26–29 ]…”

“…[1,14,15] Several studies have considered the growth of (In)GaN on SAM substrates using hydride vapor phase epitaxy (HVPE), [1,14,15] metal-organic VPE (MOVPE), [7,8,[18][19][20][21] molecular beam epitaxy (MBE), [22,23] and pulsed-laser deposition (PLD), [24,25] and the fabrication of light-emitting diode (LED) structures. [26][27][28][29] In these procedures, a low-temperature (LT) buffer layer [30][31][32] is generally used in the heteroepitaxial growth of (In)GaN. The LT buffer layer suppresses the effects caused by lattice mismatch and improves the wettability and the sticking probability of the grown material to the heterosubstrates.…”

“…[29] The LT buffer layer is effective at suppressing solid-phase diffusion, and numerous reports have been published on the growth of (In)GaN on SAM substrates using an LT buffer layer. [1,7,8,14,15,18,[26][27][28][29] However, high-quality (In)GaN can be grown directly without an LT buffer layer because the lattice mismatch between SAM and (In)GaN is small, as mentioned above.…”