Flexible single-crystalline GaN substrate by direct deposition of III-N thin films on polycrystalline metal tape
Flexible single-crystalline GaN substrate by direct deposition of III-N thin films on polycrystalline metal tape
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DOI：
10.1039/d0tc04634e
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发表时间：
2021-03
影响因子：
6.4
通讯作者：
Shahab Shervin;Mina Moradnia;Md Kamrul Alam;T. Tong;M. Ji;Jie Chen;S. Pouladi;T. Detchprohm;R. Forrest;J. Bao;R. Dupuis;J. Ryou
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文献类型：
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作者：
Shahab Shervin;Mina Moradnia;Md Kamrul Alam;T. Tong;M. Ji;Jie Chen;S. Pouladi;T. Detchprohm;R. Forrest;J. Bao;R. Dupuis;J. Ryou
基于III-N族半导体材料的柔性电子和机械可弯曲器件正在出现;然而，在制造中存在若干挑战，例如降低成本、器件稳定性和柔性以及器件性能改进。为了克服这些限制，有必要用单晶柔性模板取代脆性和昂贵的半导体晶片，以用于新的带隙半导体平台。半导体材料的新概念中的衬底具有由柔性金属带衬底上的单晶III-N薄膜组成的混合结构，其提供方便且可扩展的卷对卷沉积工艺。我们提出了一个独特的和简单的直接外延生长技术的结晶度转换提供单晶GaN薄膜的高度取向晶粒沿着两个轴和c轴方向上的灵活和多晶铜带的详细研究。具有与纤锌矿结构的（0001）基面相同的原子构型的2维（2D）石墨烯被用作在随后的III-N外延生长中起关键作用的晶种层。然后，在优化的条件下，应用直流反应磁控溅射方法来存款AlN层，以实现择优取向生长。最后，采用金属有机化学气相沉积（MOCVD）技术在双轴织构缓冲层上外延生长了单晶GaN层（~ 1 μm）。使用该方法获得的柔性单晶GaN薄膜为追求柔性、高性能和多功能器件技术的宽带隙半导体平台提供了新的途径。
Flexible electronics and mechanically bendable devices based on Group III-N semiconductor materials are emerging; however, there are several challenges in manufacturing, such as cost reduction, device stability and flexibility, and device-performance improvement. To overcome these limitations, it is necessary to replace the brittle and expensive semiconductor wafers with single-crystalline flexible templates for a new-bandgap semiconductor platform. The substrates in the new concept of semiconductor materials have a hybrid structure consisting of a single-crystalline III-N thin film on a flexible metal tape substrate which provides a convenient and scalable roll-to-roll deposition process. We present a detailed study of a unique and simple direct epitaxial growth technique for crystallinity transformation to deliver single-crystalline GaN thin film with highly oriented grains along both a-axis and c-axis directions on a flexible and polycrystalline copper tape. A 2-dimensional (2D) graphene having the same atomic configuration as the (0001) basal plane of wurtzite structure is employed as a seed layer which plays a key role in following the III-N epitaxy growth. The DC reactive magnetron sputtering method is then applied to deposit an AlN layer under optimized conditions to achieve preferred-orientation growth. Finally, single-crystalline GaN layers (∼1 μm) are epitaxially grown using metal organic chemical vapor deposition (MOCVD) on the biaxially-textured buffer layer. The flexible single-crystalline GaN film obtained using this method provides a new way for a wide-bandgap semiconductor platform pursuing flexible, high-performance, and versatile device technology.