[11p-W934-1~8] 先端イオン顕微鏡技術のナノスケール材料・デバイスへの展開

▲ [11p-W934-6] YBa₂Cu₃O₇ nano SQUIDs fabricated with a focused helium ion beam

〇Shane Andrew Cybart¹、Hao Li¹、Ethan Cho¹ (1.UC Riverside)

キーワード：superconductor, ybco, helium ion micrscope

Direct write patterning of high-transition temperature (high-T_C) superconducting oxide thin films with a focused helium ion beam is a formidable approach for the scaling of high-T_C circuit feature sizes down to the nano-scale. Here we present the use of this technique to create nano-scale superconducting quantum interference devices (SQUID) with pick-up loops as small as 10 x 10nm. The SQUID is defined entirely by helium ion irradiation from a gas field ion source focused to a sub-nm diameter. The irradiation converts the superconductor to an insulator, and no material is milled away or etched. In this manner, the device is created entirely within the plane of the film. SQUID properties such as critical current, dynamic resistance and inductance can be precisely controlled to optimize performance.Electrical measurements reveal large (0.8mV) modulation voltages with applied magnetic field and white noise values below 1μ φ_0 per √(Hz).