Ahn Min-Joo, Jeong Woo-Seop, Shim Kyu-Yeon, Kang Seongho, Kim Hwayoung, Kim Dae-Sik, Jhin Junggeun, Kim Jaekyun, Byun Dongjin
Department of Materials Science and Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Natural Science Research, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Materials (Basel). 2023 Mar 20;16(6):2462. doi: 10.3390/ma16062462.
This study provides experimental evidence regarding the mechanism of gallium nitride (GaN) selective-area growth (SAG) on a polished plateau-patterned sapphire substrate (PP-PSS), on which aluminum nitride (AlN) buffer layers are deposited under the same deposition conditions. The SAG of GaN was only observed on the plateau region of the PP-PSS, irrespective of the number of growth cycles. Indirect samples deposited on the bare c-plane substrate were prepared to determine the difference between the AlN buffer layers in the plateau region and silicon oxide (SiO2). The AlN buffer layer in the plateau region exhibited a higher surface energy, and its crystal orientation is indicated by AlN [001]. In contrast, regions other than the plateau region did not exhibit crystallinity and presented lower surface energies. The direct analysis results of PP-PSS using transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) are similar to the results of the indirect samples. Therefore, under the same conditions, the GaN SAG of the deposited layer is related to crystallinity, crystal orientation, and surface energy.
本研究提供了关于在抛光的平台图案化蓝宝石衬底（PP-PSS）上氮化镓（GaN）选择性区域生长（SAG）机制的实验证据，在该衬底上，在相同沉积条件下沉积了氮化铝（AlN）缓冲层。无论生长周期数如何，GaN的SAG仅在PP-PSS的平台区域观察到。制备沉积在裸c面衬底上的间接样品，以确定平台区域的AlN缓冲层与氧化硅（SiO2）之间的差异。平台区域的AlN缓冲层表现出更高的表面能，其晶体取向由AlN [001]表示。相比之下，平台区域以外的区域没有表现出结晶性，并且表面能较低。使用透射电子显微镜（TEM）和电子背散射衍射（EBSD）对PP-PSS进行的直接分析结果与间接样品的结果相似。因此，在相同条件下，沉积层的GaN SAG与结晶性、晶体取向和表面能有关。
