TY - JOUR
T1 - Role of insoluble atoms in the formation of a three-dimensional buffer layer in inverted Stranski–Krastanov mode
AU - Yamashita, Naoto
AU - Mitsuishi, Ryo
AU - Nakamura, Yuta
AU - Takeda, Keigo
AU - Hori, Masaru
AU - Kamataki, Kunihiro
AU - Okumura, Takamasa
AU - Koga, Kazunori
AU - Shiratani, Masaharu
N1 - Funding Information:
This work was supported in part by the Japan Society for the Promotion of Science KAKENHI grant numbers JP21H01372, JP18H01206, JP22K14292), and Iketani Science and Technology Foundation. The authors thank Dr. Naho Itagaki for experimental support including VUVAS measurements, fabrication, and analysis of thin films. We thank Michael Scott Long, PhD, from Edanz ( https://jp.edanz.com/ac ) for editing a draft of this manuscript.
Funding Information:
This work was supported in part by the Japan Society for the Promotion of Science KAKENHI grant numbers JP21H01372, JP18H01206, JP22K14292), and Iketani Science and Technology Foundation. The authors thank Dr. Naho Itagaki for experimental support including VUVAS measurements, fabrication, and analysis of thin films. We thank Michael Scott Long, PhD, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.
Funding Information:
This work was partly supported by JSPS KAKENHI (Grant Numbers JP21H01372, JP18H01206, JP22K14292), and Iketani Science and Technology Foundation.
Publisher Copyright:
© 2023, The Author(s), under exclusive licence to The Materials Research Society.
PY - 2023/3/14
Y1 - 2023/3/14
N2 - The inverted Stranski–Krastanov (SK) mode is useful for heteroepitaxial growth of single-crystalline ZnO films on 18% lattice-mismatched sapphire substrates. We studied the role of nitrogen atoms during fabrication of a three-dimensional island-shaped buffer layer. We found an unprecedented maximum in the substrate temperature dependence of the density of the crystal grains, which facilitated the growth of flat ZnO layers. To reveal the mechanism of the aforementioned maximum, we measured the absolute N atom density in Ar/N2 sputtering plasma [N]plasma by vacuum-ultraviolet absorption spectroscopy. At [N]plasma = 2.2 × 1010 cm−3, we fabricated a ZnO film with a pit-free surface, attributable to the large surface reaction probability and small incorporation ratio of N atoms into the ZnO films. To describe these results, we applied an Ising model. The analytical calculations provide insights for inverted SK mode and clearly reveal the critical effects of the flux densities. Graphical abstract: [Figure not available: see fulltext.]
AB - The inverted Stranski–Krastanov (SK) mode is useful for heteroepitaxial growth of single-crystalline ZnO films on 18% lattice-mismatched sapphire substrates. We studied the role of nitrogen atoms during fabrication of a three-dimensional island-shaped buffer layer. We found an unprecedented maximum in the substrate temperature dependence of the density of the crystal grains, which facilitated the growth of flat ZnO layers. To reveal the mechanism of the aforementioned maximum, we measured the absolute N atom density in Ar/N2 sputtering plasma [N]plasma by vacuum-ultraviolet absorption spectroscopy. At [N]plasma = 2.2 × 1010 cm−3, we fabricated a ZnO film with a pit-free surface, attributable to the large surface reaction probability and small incorporation ratio of N atoms into the ZnO films. To describe these results, we applied an Ising model. The analytical calculations provide insights for inverted SK mode and clearly reveal the critical effects of the flux densities. Graphical abstract: [Figure not available: see fulltext.]
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U2 - 10.1557/s43578-022-00886-7
DO - 10.1557/s43578-022-00886-7
M3 - Article
AN - SCOPUS:85146031464
SN - 0884-2914
VL - 38
SP - 1178
EP - 1185
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 5
ER -