The hybrid SET activity at INRIM

The hybrid Single Electron Transistor is a promising device for the realization of an accurate standard for the electrical current. Recently, it has been demonstrated that SET in hybrid configuration SINIS or NISIN (S= Superconductor, N=Normal metal) can work as electron turnstile, with a very low uncertainties due to uncontrolled tunnelling events. At INRIM Single Electron Transistors (SET) are realized by means of two alternative approaches. The first consists in the shadow mask evaporation technique. The second is the Self aligning in-line technique. The two approaches employed at INRIM in realizing hybrid SETs will be described in detail, and critically discussed.