Miniature vector magnetometer for scanning squid microscopy

Abstract

We have demonstrated a miniature vector magnetometer for imaging three orthogonal components of the magnetic field in close proximity to a planar sample. This magnetometer consists of three separate SQUIDs fabricated adjacent to each other on a planar substrate using a planarized three-level-of-metal Iow-Tc process with features as small as 0. 8 μn. The z-axis SQUID has a conventional single square pick-up loop approximately 10 μn in size that connects to remotely located tunnel junctions via a totally enclosed planar coaxial lead structure. The x- and y-axis SQUIDs are of similar design except that the pick-up structures are in the form of multiple-turn planar solenoids about 10 ftm in size. In this paper we will discuss the design fabrication and characterization of the devices along with initial results of the imaging of individual trapped flux quanta. © 1997 IEEE.