Epitaxial growth of superconducting MgB2 thin films with a Mg buffer layer at 110 °C

29th International Symposium on Superconductivity

Shishido, Hiroaki^1,2 ; Nakagami, Takatoshi^1 ; Yoshida, Takuya^1 ; Ishida, Takekazu^1,2

Department of Physics and Electronics, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka

599-8531, Japan^1

Institute for Nanofabrication Research, Osaka Prefecture University, Sakai, Osaka

599-8531, Japan^2

关键词: Low growth temperature;    Low substrate temperature;    Micro-fabrication techniques;    Nanofabrication techniques;    Sapphire substrates;    Superconducting electronics;    Superconducting transitions;    X-ray diffraction measurements;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/871/1/012036/pdf
DOI  :  10.1088/1742-6596/871/1/012036

来源: IOP

【 摘 要 】

Since the discovery of MgB2, its application to superconducting electronics has been limited by the absent of proper microfabrication techniques. In this study, we grew crystalline MgB2thin films using molecular beam epitaxy at a low substrate temperature of 110 °C under ultra-high vacuum of about 10-6Pa. MgB2thin films were deposited with an epitaxial Mg buffer layer on c-plane 4H-SiC or sapphire substrates. In spite of the low growth temperature, superior crystallinity and surface flatness were confirmed by in situ reflection high-energy electron diffraction and X-ray diffraction measurements. Moreover, we successfully confirmed the occurrence of a sharp superconducting transition at 27 K. The present growth temperature was lower than any in prior reports on superconducting MgB2thin films, and is lower than the applicable temperature of an organic-based lift-off resist. Our new MgB2thin film growth process is promising for the development of an alternative nanofabrication technique for MgB2thin films by means of a standard lift-off process with an organic resist.