A technique relates to protecting a tunnel junction. A first electrode paddle and a second electrode paddle are on a substrate. The first and second electrode paddles oppose one another. A sacrificial shorting strap is formed on the substrate. The sacrificial shorting strap connects the first electrode paddle and the second electrode paddle; The tunnel junction is formed connecting the first electrode paddle and the second electrode paddle, after forming the sacrificial shorting strap. The substrate is mounted on a portion of a quantum cavity. The portion of the quantum cavity is placed in a vacuum chamber. The sacrificial shorting strap is etched away in the vacuum chamber while the substrate is mounted to the portion of the quantum cavity, such that the sacrificial shorting strap no longer connects the first and second electrode paddles. The tunnel junction has been protected from electrostatic discharge by the sacrificial shorting strap.