2010 Fiscal Year Final Research Report

The development of the 3D magnetic sensor using the nano-SQUID

Research Project

Project/Area Number	21710143
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Microdevices/Nanodevices
Research Institution	National Institute of Advanced Industrial Science and Technology
Principal Investigator	MATSUMOTO Tetsuro National Institute of Advanced Industrial Science and Technology, エレクトロニクス研究部門, 産総研特別研究員 (50450672)
Project Period (FY)	2009 – 2010
Keywords	ナノSQUID / 弱結合 / ジョセフソン接合 / 磁気センサー
Research Abstract	We develop a fabrication process of Nb based nano-SQUIDs that can be applied for three dimensional magnetic sensor. The SQUIDs were fabricated using Nb, Nb/W, Nb/Au films and patterned by a conventional lithography and a focused ion beam (FIB) process. The bilayer films were found to be effective to reduce the effects of the self-heating and to avoid the degradation due to the Ga ion diffusion during the FIB process. We succeeded in fabricating bilayer nano-SQUIDs having nonhysteretic I-V characteristics with Ic down to 30mA at 4.2K. Ic values could be easily tuned by changing the FIB pattern. Therefore, the present fabrication process has the flexibility to optimize the SQUID design for various measurement environments, such as for high magnetic field (～1T) and for low temperature (0.1K).