Shunt-protected single-electron tunneling circuits fabricated on a quartz wafer

We address fabrication challenges for the single-electron tunneling (SET) devices, based on ultrasmall junctions Al/AlO
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/Al. Nanoscale SET components are known to be very fragile in respect to electrostatic breakdown, which turns out to be a critical problem for devices, fabricated on insulating substrates. For the breakdown prevention, we successfully realized on-chip silicon shunts, whose conductivity advantageously vanished at low temperatures, making possible undisturbed SET operation at T ~ 100 mK.