  We have developed a novel Josephson junction geometry with minimal volume of
lossy isolation dielectric, being suitable for higher quality trilayer
junctions implemented in qubits. The junctions are based on in-situ deposited
trilayers with thermal tunnel oxide, have micron-sized areas and a low subgap
current. In qubit spectroscopy only a few avoided level crossings are observed,
and the measured relaxation time of $T_1\approx400\;\rm{nsec}$ is in good
agreement with the usual phase qubit decay time, indicating low loss due to the
additional isolation dielectric.

Superconductivity