23rd IMEKO TC 4 International Symposium and the 5th Chinese Conference on Electromagnetic Metrology Technical (IMEKO TC4 2019)

134 / 2019-01-24 21:06:13

Investigation of nano-SQUIDs with Dayem bridges by e-beam lithography and reaction ion etching

Nano-SQUID, E-beam, RIE, Measurement

Plenary track > Direct Current and Low Frequency Measurements

Nano-SQUIDs are sensitive devices for quantum detection and precision measurements due to the ultra-low noise level. This paper reports the fabrication and characterization of nano-SQUIDs by e-beam lithography and reaction ion etching (RIE). Nano-SQUIDs were comprised by two Dayem nanobridges and a loop based on monolayer Nb film. The width of the nanobridges was 94 nm and the diameter of the loop was 20 μm. A measurement system based on a physical properties measurement system and source-meters. The voltage-bias current (Ibias-V) at different temperatures showed that the working range of the nano-squid was 8.3 K to 7.0 K. The voltage-modulation flux (V-Ф) were characterized at 8.2 K and the flux modulation depth was large to be 74.5% with the bias current 287 μA. The Ibias-V and V-Ф (Icoil) showed that the e-beam lithography and RIE process were befitting for fabrication of nano-SQUIDs.