Self‐contained measurement of thin‐film superconducting penetration depths and nonsuperconducting film thicknesses in Josephson integrated circuits

摘要

In measurements of superconducting thin‐film penetration depths, the need for a reference penetration depth has been eliminated by a modification of the direct‐coupled SQUID technique. Furthermore, the technique is convenient for accurate measurements of insulator and thin‐film resistor thicknesses in superconducting integrated circuits. Measurements of the penetration depths and insulator thicknesses have been obtained on different chips from a few wafers of a single fabrication run. The results indicate for the first time, on a small scale, the degree of chip‐to‐chip and wafer‐to‐wafer control presently obtainable for these parameters.