Ex situ tunnel junction process technique characterized by Coulomb blockade thermometry

摘要: The authors investigate a wafer scale tunnel junction fabrication method, where plasma etched via through dielectric layer covering bottom Al electrode defines the area. ex situ barrier is formed by oxidation of in Room temperature resistance mapping over 150 mm gives local deviation values that fall below 7.5% with an average 1.3%. further investigated sub-1 K measurements device, which has one connected to four arrays consisting N junctions (N=41, diameter 700 nm). differential conductance measured single-junction and array Coulomb blockade thermometer operation modes. By fitting experimental data theoretical models, found upper limit for ∼5% 2N+1 junctions. This value same order as minimum detectable defined ...