Scanning SQUID microscopy of integrated circuits
Abstract
We have used a scanning YBa2Cu3O7 superconducting quantum interference device (SQUID) at 77 K to image currents in room-temperature integrated circuits. We acquired magnetic field data and used an inversion technique to convert the field data to a two-dimensional current density distribution, allowing us to locate current paths. With an applied current of 1 mA at 3 kHz, and a 150 μm separation between the sample and the SQUID, we found a spatial resolution of 50 μm in the converted current density images. This was about three times smaller than the SQUID-sample separation, i.e., three times better than the standard near-field microscopy limit, and about 10 times sharper than the raw magnetic field images.
- Publication:
-
Applied Physics Letters
- Pub Date:
- April 2000
- DOI:
- 10.1063/1.126327
- Bibcode:
- 2000ApPhL..76.2304C
- Keywords:
-
- 85.40.Qx;
- 85.25.Dq;
- 07.50.-e;
- 07.07.Df;
- Microcircuit quality noise performance and failure analysis;
- Superconducting quantum interference devices;
- Electrical and electronic instruments and components;
- Sensors;
- remote sensing