Maskless Patterning of Gallium-Irradiated Superconducting Silicon Using Focused Ion Beam
Ryo Matsumoto, Shintaro Adachi, El Hadi S. Sadki, Sayaka Yamamoto, Hiromi Tanaka, Hiroyuki Takeya, Yoshihiko Takano
Abstract
A direct patterning technique of gallium-irradiated superconducting silicon has been established by a focused gallium-ion beam without any mask-based lithography process. The electrical transport measurements for line- and square-shaped patterns of gallium-irradiated silicon were carried out under self-field and magnetic field up to 7 T. Sharp superconducting transitions were observed in both patterns at a temperature of 7 K. The line pattern exhibited a signature of higher onset temperature at around 12 K. A critical dose amount to obtain the superconducting gallium-irradiated silicon was investigated by the fabrication of various samples with different doses. This technique can be used as a simple fabrication method for a superconducting device.