Influence of Temperature‐Dependent Substrate Decomposition on Graphene for Separable GaN Growth

Abstract

voltage, high mobility, high luminous efficiency, long service life, and tunable bandgap energy by adjusting the aluminum and indium composition covering from ultraviolet to infrared. However, there are drawbacks for GaN. For example, growing GaN on a sapphire or silicon (111) substrate generates dislocation due to lattice mismatch between the GaN epitaxial layer and the substrate. In addition, the strong chemical bond at the interface makes it difficult to separate the epitaxial layer from the substrate, which limits the ability to apply GaN with excellent properties in various fields. Recently, several studies have sought to overcome these problems by adopting 2D materials between the epitaxial layer and the substrate.Xu and co-workers reported the reduced dislocation density in GaN/graphene/GaN structure using self-organized graphene as a nanomask at high-temperature in hydrogen (H 2 ) ambient with many graphene defects. [1,2] Liu and co-workers also reported that when aluminum nitride was grown on plasma-treated graphene, the dislocation density was reduced compared to when directly grown on sapphire. [3] Hong and co-workers proved that the embedded graphene oxide could be used to improve the heat dissipation in GaN light-emitting diodes. [4,5] In addition, other researchers are making efforts to separate epitaxially grown III−V films from the substrate with the help of the 2D material making the weak chemical bond between the epitaxial layer and the substrate that is transferred to the substrate such as graphene/silicon dioxide, [6] graphene/silicon carbide, [7,8] graphene/ gallium arsenide (GaAs), [9] and boron nitride/sapphire [10] structures. Very recently, Kim and co-workers reported demonstration results using various semiconductors that showed that the polarity of 2D materials and bulk play a crucial role in remote epitaxy. The article also provides the necessary general understanding of single-crystalline growth on 2D-material-coated substrates and subsequent exfoliation. [11] However, the earlyreported graphene-loss issue, particularly in GaN growth in metal-organic chemical vapor deposition (MOCVD), remains unclear and warrants investigation to take advantages of graphene in III−V compound semiconductor growth.Here, we investigated how the decomposition of substrates that support the graphene layer affect the graphene layer by Graphene has been adopted in III−V material growth since it can reduce the threading dislocations and the III−V epilayer can easily be separated from the substrate due to the weak chemical bond. However, depending on the substrate supporting the graphene, some substrates decompose in the III−V material growth environment, which results in the problem that no graphene remains. In this study, the influence of temperature-dependent substrate decomposition on graphene through an annealing process that resembles conventional growth conditions in metal-organic chemical vapor deposition (MOCVD) is investigated. It is also confirmed that trimethylgallium, hydrogen, and ammonia gases d...

Remote heteroepitaxy of GaN microrod heterostructures for deformable light-emitting diodes and wafer recycle

“…For the use of graphene substrate, because graphene does not form the covalent bonds with the overlayer NWs, the interfacial strain can be efficiently released through the small footprint (25). Furthermore, the high chemical inertness and thermal stability of graphene do not cause the contamination to the NWs even above 1000°C (26)(27)(28). Hence, graphene is one of the ideal substrate materials that can resolve the issues mentioned above for growing high-quality optoelectronic components.…”

“…However, it is well known that the use of Al 2 O 3 wafer with a large in-plane lattice mismatch of 16.1% is quite beneficial because of its large scalable and well-compatible processing for the conventional GaN growth. Meanwhile, Park et al (28) have recently reported that the sapphire wafer is more stable than GaN substrate under harsh reaction conditions of hydrogen-and ammonia-rich high growth temperature of more than 1000°C when the surface is coated with graphene, and graphene is also robust in the same ambi-ence. Thus, it is expected that such tolerance of Al 2 O 3 is exploitable to allow recycling of the wafer after the release of the overlayer.…”

Graphene Buffer Layer on SiC as a Release Layer for High-Quality Freestanding Semiconductor Membranes

“…Damaged 2D materials and the associated defective van der Waals surfaces can lead to failure in releasing the membranes. For example, the graphene used for GaN growth can be damaged by H 2 carrier gas during growth at high growth temperature and by NH 3 or nitrogen plasma during metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) growth. , Simultaneously achieving a high-quality epilayer and maintaining a robust van der Waals surface, which is the key to fabricating free-standing single-crystalline semiconductor membranes, has been one of the greatest challenges faced by the community.…”

MOVPE Growth of GaN via Graphene Layers on GaN/Sapphire Templates

“…Meanwhile, the graphene fingerprint peaks were also detected on the GaN membrane. This indicates that the damage to the graphene layer occurs not only during the growth of GaN epilayer [ 9 , 37 ], but also due to the exfoliation. The graphene interlayer was probably ripped during the exfoliation, with some flakes of graphene stuck to the GaN membrane.…”